Citation
The Application of Green Infrastructure in Chinese Urban Stormwater Management

Material Information

Title:
The Application of Green Infrastructure in Chinese Urban Stormwater Management
Creator:
Wei, Ying
Place of Publication:
[Gainesville, Fla.]
Publisher:
College of Design, Construction and Planning, University of Florida
Publication Date:
Language:
English
Physical Description:
Project in lieu of thesis

Thesis/Dissertation Information

Degree:
Master's ( Master of Science in Architectural Studies)
Degree Grantor:
University of Florida
Degree Disciplines:
Architecture
Committee Chair:
Nawari, Nawari O
Committee Co-Chair:
Volk, Michael Ives

Subjects

Subjects / Keywords:
Bodies of water ( jstor )
Groundwater ( jstor )
Infrastructure ( jstor )
Rain ( jstor )
Stormwater ( jstor )
Stormwater management ( jstor )
Surface runoff ( jstor )
Water balance ( jstor )
Water reuse ( jstor )
Water usage ( jstor )

Notes

Abstract:
After falling down to the ground, most rainwater will be absorbed and filtered by the ground surface with high porosity, for instance, forest, meadow and soil, before running off into rivers, lakes and subterranean water. Thus, either less flood frequency or water quality are guaranteed by eco-system itself. However, as a result of rapid urbanization, those unexploited high porosity ground surface is inevitably replaced by impervious surface (asphalt roads, building footprints, paved street, etc.) which blocks rainwater from infiltrating. The drainage system has been acting as a protagonist, especially in modern urban context, to deal with flood and water management ever since invented. Nonetheless, though tons of stormwater is quickly drained though the system, yet pollutants such as general trash, substance with heavy metal element, bacteria, and phosphorus compounds collected from the imperious surface it travelled, are simultaneously drained directly into the system along with the stormwater polluting the waterways. ( ,, )
Abstract:
Green Stormwater Infrastructure (GSI) is a new approach to managing stormwater. GSI is a natural vegetation based system that can intercept stormwater, filter out pollutants and reduce runoff through ecological approaches with plants, soils and microbes. It could be green roofs, bioswales, permeable pavement and other components with the landscape that are designed to maintain natural hydrology functions by absorbing and infiltrating systems.
Abstract:
The research on stormwater management in China is still on early stage. This study focuses on solving urban waterlog problem in Wuhan, one of the big city in China, seeking to develop a stormwater management system by integrating green infrastructure, landscape elements in the neighborhood. Being able to manage runoff and other water resources, the stormwater management system will be a comprehensive, sustainable, and ecologically means to solve the complex stormwater environment problems.
General Note:
sustainable design terminal project

Record Information

Source Institution:
University of Florida
Holding Location:
University of Florida
Rights Management:
Copyright Ying Wei. Permission granted to the University of Florida to digitize, archive and distribute this item for non-profit research and educational purposes. Any reuse of this item in excess of fair use or other copyright exemptions requires permission of the copyright holder.
Resource Identifier:
1022120845 ( OCLC )

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PAGE 1

1 THE APPLICATION OF GREEN INFRASTRUCTURE IN CHINESE URBAN STORMWATER MANAGEMENT By YING WEI A THESIS PRESENTED TO THE GRADUATE SCHOOL OF THE UNIVERSITY OF FLORIDA IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE IN ARCHITECTURAL STUDIES UNIVERSITY OF FLORIDA 2015

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2 © 2015 Ying Wei

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3 To my parents, friends and colleagues

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4 ACKNOWLEDGMENTS Thank my parents for their s upport and cultivate to bring me up. Thank my committee member, Professor Nawari,Nawari, Professor Volk, Michael and Professor William Tilson for their advice, encourage and their tireless to help me writing this thesis. Besides, I would thank Mr. Michael Kung for hi s help and technic al support. Furthermore, I would thank my boyfriend, my friends and my colleagues for such as family like care and help during this year. Last but not least, I would thanks to the University of Florida and Huazhong University of Science and Techno logy to give me a chance to see the world and experience a different life.

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5 TABLE OF CONTENTS page ACKNO WLEDGMENTS ................................ ................................ ................................ . 4 TABLE OF CONTENTS ................................ ................................ ................................ .. 5 LIST OF TABLES ................................ ................................ ................................ ......... 10 LIST OF FIGURE S ................................ ................................ ................................ ........ 11 LIST OF ABBREVIATIONS ................................ ................................ .......................... 12 CHAPTER 1 ................................ ................................ ................................ .................. 15 INTRODUCTION ................................ ................................ ................................ ........... 15 Rapid Urbanization in China, Wuhan ................................ ................................ ........ 15 Green Infrastructure ................................ ................................ ................................ .. 17 Comparis on of Conventional Drainage System with Green Infrastructure ................ 20 Based Strategies ................................ ................................ ................................ ....... 20 CHAPTER 2 ................................ ................................ ................................ .................. 21 LITERATURE REVIEW ................................ ................................ ................................ 21 Policies and Laws ................................ ................................ ................................ ..... 21 Green Infrastructure Benefits ................................ ................................ .................... 22 Flooding Control ................................ ................................ .............................. 22 Water resource reuse ................................ ................................ ...................... 22 Water qu ality control ................................ ................................ ........................ 23 Functional Landscape ................................ ................................ ...................... 23 Cost Saving ................................ ................................ ................................ ..... 23 Stormwater Management in American ................................ ................................ ...... 24 Low Impact Development (LID) ................................ ................................ ....... 24 Best Management Practices (BMP) ................................ ................................ . 25

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6 Environmental Site Design (ESD) ................................ ................................ .... 25 Water Sensitive Urban Design ................................ ................................ ......... 26 United State Environmental Protection Agency (EPA) Stormwater Management Programs ................................ ................................ ................................ ........... 27 ................................ ................................ ............. 28 Plan Eas t Tennessee (PlanET) ................................ ................................ ........ 29 Water Sense ................................ ................................ ................................ .... 29 Stormwater Management in China ................................ ................................ ............ 30 Climate Change ................................ ................................ ............................... 31 Urbanization ................................ ................................ ................................ ..... 31 The Lagging Drainage System Developments ................................ ................. 32 Inadequate Urban Planning ................................ ................................ ............. 32 Po licies, Legislatures on Flood Protection in China ................................ ......... 33 Onsite and Neighborhood Stormwater Control Measures ................................ ......... 33 Stormwater Storage ................................ ................................ ......................... 34 Infiltration Measures ................................ ................................ ......................... 36 Conveyance Measures ................................ ................................ .................... 36 Filtration Measures ................................ ................................ .......................... 37 Integral Stormwater Management Master Plan and Design in a Community ............ 38 Using Landscape Elements and Site Conditions to Building a Multi functional Storage System ................................ ................................ ........................... 39 Building a Recycled and Reused Water System ................................ .............. 39 Integrating Dispersed and Centralized GSI ................................ ...................... 40 CHAPTER 3 ................................ ................................ ................................ .................. 41 METHODOLOGY ................................ ................................ ................................ .......... 41 Water Balance Calculation in the Community ................................ ........................... 45

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7 Calculate Water Use and Water Loss ................................ .............................. 46 Calculate water supply ................................ ................................ ..................... 46 Questionnaire ................................ ................................ ................................ ............ 47 Archival Research ................................ ................................ ................................ ..... 48 CHAPTER 5 ................................ ................................ ................................ .................. 49 ARCHIVAL RESEARCH ................................ ................................ ............................... 49 Sino Singapore Tianjin Eco City(SSTEC) ................................ ................................ .. 49 Sustainable Approaches ................................ ................................ .................. 49 Parkmerced Vision Project ................................ ................................ ........................ 51 Su stainable Approaches ................................ ................................ .................. 51 Oriental Sun City Community ................................ ................................ .................... 53 Sustainable Approaches ................................ ................................ .................. 54 CHAPTER 6 ................................ ................................ ................................ .................. 56 DISCUSSION AND ANA LYSIS ................................ ................................ .................... 56 Date of Water Balance ................................ ................................ .............................. 56 The Reused Water Volume in the Buildings ................................ .................... 56 The Volume of Rainwater ................................ ................................ ................ 56 The Evaporation Volume of Landscape Water ................................ ................ 56 The Infiltrate Volume of Landscape Water ................................ ....................... 57 The Car Washing Consumption ................................ ................................ ....... 57 Irrigation Water Consumption ................................ ................................ .......... 57 The Roads and Squares Washing Water Consumption ................................ ... 57 Water Balance ................................ ................................ ................................ . 58 Water Balance Evaluation ................................ ................................ ......................... 60 Evaluate the Flood Control Ability of GSI ................................ ......................... 60 Evaluate the Water Resource Reuse System ................................ .................. 61

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8 Date of the Questionnaire ................................ ................................ ......................... 61 Questionnaire Evaluation ................................ ................................ .......................... 63 Evaluate the Control Water Quality ................................ ................................ .. 63 Evaluate Landscape Function ................................ ................................ .......... 63 Evaluate Cost Saving ................................ ................................ ....................... 63 Applicat ion: Optimization Measures of GSI in the Comunity ................................ ..... 63 Centralized GSI as the Main Treatment Measures, Dispersed GSI as A Supplemen t ................................ ................................ ................................ .. 63 Dispersed GSI as the Main Treatment Measures ................................ ............ 64 CHAPTER 6 ................................ ................................ ................................ .................. 65 CONCLUSION ................................ ................................ ................................ .............. 65 Impediments of Sto rmwater Management in Wuhan ................................ ................ 65 Lake of Basic Hydrologic Data and Research Gaps Existing in Theory and Implementation ................................ ................................ ............................ 66 Ineffective Integration of Stormwater Management to Urban Planning ............ 6 7 Poor Operational and Maintenance Practices ................................ .................. 67 Public Participation and Public Support is Insufficient and Lack of Funding Support ................................ ................................ ................................ ........ 68 Suggestions to Stormwater Ma nagement Policies ................................ .................... 68 Problem 1: Lake of Basic Hydrologic Data and Research Gaps Existing in Theory and Implementation ................................ ................................ ......... 69 Problem 2: Ineffective Integration of Stormwater Management to Urban Planning ................................ ................................ ................................ ....... 69 Problem 3: Poor Operational and Maintenance Practices ............................... 70 Problem 4: Public Participation and Public Support is Insufficient and Lack of Funding Support ................................ ................................ .......................... 70

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9 APPENDIX ................................ ................................ ................................ ................ 72 LIST OF REFERENCES ................................ ................................ ............................... 84

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10 L IST OF TABLES Table page Table 0 1 Statistics of the water levels above 27.30 meters measured in Wuhanguan water station between 1865 and 2003 ................................ ................................ ........... 7 2 Table 0 2 treatment for stormwater management of WSUD ................................ ......... 72 Table 0 3 Typically green infrastracture approaches from the smaller scale elements to larger scale elements that can be integrated into sites ................................ .................. 7 3 Table 0 4 questionnaire for the green infrastracture in Wuhan ................................ ..... 7 4 Table 0 5 Monthly water balance data ................................ ................................ .......... 7 5 Table 0 6 the water balance chart of landscape water for year ................................ ..... 7 6

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11 LIST OF FIGURES Figure page Figure 0 1 the comprehensive water balance chart in the community .......................... 7 6 Figure 0 2 the evaluation framework ................................ ................................ ............. 77 Figure 0 3 the community location ................................ ................................ ................ 78 Figure 0 4 the coomunity general plan ................................ ................................ .......... 78 Figure 0 5 Flow diagram of reused water resourced harvesting in the community ....... 79 Figure 0 6 the water balance calculating analysis ................................ ......................... 79 Figure 0 7 the comprehensive water balance chart in the community .......................... 8 0 Figure 0 8 schematic diagram of the stormwater management master plan ................. 8 0 Figure 0 9 the detail of non traditional water consumption in the community ................ 8 1 Figure 0 10 background information of survey people ................................ .................. 8 1 Figure 0 ................................ 8 2 Figure 0 ................................ ................................ .......................... 8 2 Figure 0 ............. 8 3

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12 LIST OF ABBREVIATIONS ARI Average Recurrence Interval BMP Best Management Practice EPA Environment Site Design GSI Green Stormwater Infrastructure LGA Lake George Association LID Low Impact Development Plan ET Plan East Tennessee SSTEC Sino Singapore Tianjin Eco City WSED Water Sense Urban Design

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13 Abstract of Thesis Presented to the Graduate School of the University of Florida in Partial Fulfillment of the Requirements for the Degree of Master of S cience in Architectural Studies THE APPLICATION OF GREEN INFRASTRUCTURE IN CHINESE URBAN ST ORMWATER MANAGEMENT BY YING WEI JULY 2015 Chair: Nawari,Nawari Major: Architecture Abstract After falling down to the ground, most rainwater will be absorbed and filtered by the ground surface with high porosity, for instance, forest, meadow and soil, before running off into rivers, lakes and subterranean water. Thus, either less flood fre quency or water quality are guaranteed by eco system itself. However, as a result of rapid urbanization, those unexploited high porosity ground surface is inevitably replaced by impervious surface (asphalt roads, building footprints, paved street, etc.) wh ich blocks rainwater from infiltrating. The drainage system has been acting as a protagonist, especially in modern urban context, to deal with flood and water management ever since invented. Nonetheless, though tons of stormwater is quickly drained though the system, yet pollutants such as general trash, substance with heavy metal element, bacteria, and phosphorus compounds collected from the imperious surface it travelled, are simultaneously drained directly into the system along with the stormwater pollut ing the waterways.

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14 Green Stormwater Infrastructure (GSI) is a new approach to managing stormwater. GSI is a natural vegetation based system that can intercept stormwater, filter out pollutants and reduce runoff through ecological approaches with pl ants, soils and microbes. It could be green roofs, bioswales, permeable pavement and other components with the landscape that are designed to maintain natural hydrology functions by absorbing and infiltrating systems. The research on stormwater man agement in China is still on early stage. This study focuses on solving urban waterlog problem in Wuhan, one of the big city in China, seeking to develop a stormwater management system by integrating green infrastructure, landscape elements in the neighbor hood. Being able to manage runoff and other water resources, the stormwater management system will be a comprehensive, sustainable, and ecologically means to solve the complex stormwater environment problems.

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15 CHAPTER 1 INTRODUCTION In the natural environment, a large amount of pervious surface area allows a high percentage of the water absorbed back into the ground. Stormwater is a dynamic element in the natural hydrological cycle. It plays an important role in the natural environm ent including irrigating plants and crops, recharging underground water , and keep balance of surface water with underground water. However rapid urbanization let most of natural ground replaced by impervious pavement (paved streets, parking lots, an d building rooftops) , where the water cannot soak into the ground . As a result, a large amount of stormwater are treated as waste water and discharged with pollutions. Stormwater runoff carries with different kinds of pollutions on the surface like sedimen t, trash, metals, and bacteria, so it is also the main source of pollution s refo to the stream in urban areas. D uring the rainy season, the discharge of untreated wastes often extends national standards and cause serious problems. In 1994, the total waste w ater discharge from industrial and domestic was 1228 million ton. In addition, the amount of waste water discharge has increased steadily in the past decade. Rapid U rbanization in China, Wuhan China is currently under the pr ocess of rapid urbanization with more than half of the total population, m ore than 13 million people, live in the urban area. It cause the urban built up area expand 1300km 2 annually, in the meantime, the undeveloped ground surface is inevitably replaced by impervious surface which b locks rainwater from infiltrating. For this st udy, the study area is in Wuhan, China. Wuhan was chosen because: Wuhan is one of the most important city in the center of China and it is the capital of Hubei Province. It is located at the intersection o f the Yangtze River and the Hanshui

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16 River , with three towns: Wuchang, Hanyang, and Hankou. The land area is 8,494.41 square kilometers, m ost of the land in Wuhan is plain and decorated with hills and a great number of lakes and pools. or Chicago of China From Wikipedia) as domestic transportation , economy, and politics . It is not only the place where th e river Hans joins Yangtze R iver , but al so the connect ion of three major railways and two major expressways. I n recent years , under the development of urban infrastructure and the high speed propulsion of urbanized construction, Wuhan is becoming one of the most important economic zones along th e Yangtze River Basin. In 2006, the Gross Domestic Product (GDP) of the city is 256 billion Yuan and per capita GDP is about 3790 USD. At the same time, the annual income of the urban inhabitants is 12,369 Yuan (ca. 1,237 Euros) and the rural inhabitants a re 4748 Yuan (ca.475 Euros) (Wuhanshi Tongjiju, 2006). Unfortunately, the growth of GTP also bring the tremendous changes in its land use and land cover. The water area decreases rapidly from 1991 to 2000. On ly 38 lakes reserved now compare with 127 lakes in the 1950s. The abundant wa ter resources of Wuhan distinguished it from other cities in China or even the whole world. Over 100 hills with various sizes of lakes in Wuhan take up H owever, s ince the reforms and open policy adopted in 1978, flood frequency has clearly increase d in Wuhan. Frequent floods often result in Bu t he essential urban infrastructure cannot keep pace with the economic growth and urban exp ansion in Wuhan. Short of stormwater conveyance system and flood control facilities give rise to increasing the volume of stormwater runoff and the likelihood of flooding. M any big cities in China like Beij ing, Tianjin and Sichuan are also regula rly t hreatened by flood events as well as Wuhan. In the last 800 years, Wuhan was flooded

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17 more than 50 times which cause serious consequence. One of the most serious flood disaster is in 1931, with the lowest locations in Wuhan being 6 meters under the water fo r almost 100 days. The highest level recorded was reached to 28.28 meters, while the dike level is 27.30 meters, which lead s to as much as 32600 people death in this disaster. After that, from the statistics in the Wuhanguan Water Station, the water level has exceeded 27.30 meters 13 times between 1860 and 2003. In 1996, 1998 and 1999, the flood level reached to 29.73 meters. As a result, most the factories had to interrupt was clogged by the water . The tabl e below shows the flood events during which the water level was higher than 27.30 meters. Table 0 1 Statistics of the water levels above 27.30 meters measured in Wuhanguan water station between 1865 and 2003. Source: Wuhan Shuiwuju, 2004 Year Water level Year Water level 1954 29.73 1980 27.76 1998 29.43 2002 27.76 1999 28.89 1935 27.58 1996 28.66 1968 27.39 1931 28.28 1988 27.39 1983 28.11 1870 27.36 1995 27.79 The conventional drainage system to deal with flood and water management is using pipe and catch basin to collect the wastewater. However, this strategy is just transfer the pollution to another site. As a result, tons of wastewater is quickly drained through the system and discharge into the nearby rivers and lakes. A sustainable stormwater management system are needed to solve the complex s tormwater environment problems and protect natural function of ecosystem . Green Infrastructure Green infrastru a relatively new and flexible term. It has been used differently

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18 Green Infrastructure Action Strategy of United State Environmental Protection Agency ( EPA ) . I t is processes to infiltrate, evapotranspiration or reuse stormwater or runoff on t he site where it is generated (EPA). Green infrastructures are natural systems that can capture, cleanse and reduce stormwater runoff through ecological approaches with plants, soils , and microbes (what is green infrastructure , EPA ). In the regional scale, green infrastructure can be define d an interconnected network of waterways, wetlands, woodlands, wildlife habitats and other natur al areas (The Conservation Fund, 1999 onal social ecosystems can been improved by green infrastructure. And at the site scale, green infrastructure is made up of site specific m anagement practices like rain gardens, pervious pavement, constructed wetlands that are designed to maintain natural hydrology functions by absorbing and infiltrating systems. Here are some kinds of green infrastructure range from the scale elements. Regio nal Scale: Land conservation Ecological corridor Urban tree canopy Site Scale: Green Roofs Green Parking Green Streets and Alleys Permeable Pavements Bioswales Planter Boxes Rain Gardens Rainwater Harvesting Downspout Disconnection

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19 Since green infrastructure plays an important role to solve flood disaster in Wuha n, it would be interesting to integrate st ormwater system plan with green infrastructure, landscape design and community planning. Based on the research about the functional mechan ism of green infrastructure used in stormwater management, it makes sense to explore the extent of green infr astructure used at the neighborhood. Furthermore, it would be important to put forward optimizing strategies of green stormwater infrastructu re to eliminate stormwater disaster in the neighborhood. Th is sc the green infrastructure like a green parking lot, green street, stormwater wetlands, green roof and rain garden. Under the research of t he type s and characteristics of green infrastructure in com munity scale systematically, this study is to explore the optimization method of green infrastructure to improve the stormwater management system , to alleviate waterlog and to r educe the amount of polluted stormwater runoff directly into the nearby streams or lakes . Green infrastructure is extensive used as measure s of stormwater control in some developed countries like the United States. While, the stormwater management system is sti ll in a first stages. R ecently, the Chinese government had also pay more and more attention for using green infrastructure measures to cope with recurring floods. Therefore this research aim to study the BIM ( Best Management Practices ) and Green Stormwater Infrastructure (GSI) in the United States and then find the stormwater management system suitable for Chinese conditions. There is a need to understa nd the policies and public satisfactory towards GSI . Furthermore, establish relative governments and regul ations to guide the st ormwater management and build a resilient stormwater management system. The overall goal is to integrate a stormwater management system with green infrastructure approaches in an urban neighborhood. Being able to manage runoff and oth er water resources, the stormwater management

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20 system will be a comprehensive, sustainable, and ecologically means to solve the complex stormwater environment problems. Comparison of C onventional D rainage S ystem w ith G reen I nfrastructure B ased S trategies The traditional stormwater was installed to prevent flooding and convey stormwater as quickly as they can. Grey infrastructure such as pipes, tanks, or underground storage facilities are used to convey the polluted water and then discharge the nearby water bodies. As a result, u rban imperviousness pattern and drainage stormwater system are lead to changes in hydrologic al function. One of the undesirable overflows is CSO S, which happened when the wastewater conveyance system is overwhelmed and polluted water effluence into nearby surface waters. To address this issues, and thereby reduce the volume of stormwater, municipalities have started to look for the effective and cost throu ghout their service area s (Taylor and Fletcher 2007). Green Stormwater Infrastructure (GSI) is a new approach to managing stormwater. Compar ing to the conventional drainage system, GSI is a natural vegetation based system that can intercept stormwater, fi lter out pollutants and reduce runoff through ecological approaches with plants, soils , and microbes (EPA) . It concludes green roofs, bioswales, permeable pavement and other components with the landscape that are designed to maintain natural hydrology func tions by absorbing and infiltrating systems. One of the major benefits of green infrastructure is to reduce urban runoff and pollution. Besides, it also can provide green spaces in the urban area and improve rastructure strategies are more cost effective than conventional stormwater management approaches, even when evaluated in terms of their direct costs and savings over their useful lives (Lovell & Taylor, 2013).

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21 Since green infrastru cture has a lot of benefits to managing stormwater in Wuhan, it would be interesting to integrate stormwater system plan with green infrastructure, landscape design and community planning. CHAPTER 2 LITERATURE REVIEW Policies and Laws Si nce 2008 , u rbanization result in the highe r frequency of urban flooding damage , stormwater management has attracted more and more attention. In the early 1960s, most research related to the local hydraulic representation of streets and sewer system. Then in the 1970s , impervious surface s are widely used as an approach to quantify impacts on the hydrological process. But there are still have many polluted water bodies from separated storm sewer systems in spite of the surface water quality has an effective improvement after the implement of the Clean Water Act in 1972. More currently, the study focus es on using urban landscape to manag e and control stormwater. And there is growing concern about implement urban planning technologies, such as LID ( Low Impact Development) in North America, sustainable urban drainage systems (SUDS) in the United Kingdom, water sensitive urban design (WSUD) in Australia and the Low Impact Urban Development Design (LIUDD). G reen infrastructure is one of the sustainable approache to producing win win relationship at the urban stormwater managem ent and environmental benefits. It is playing an important role of rainwater harvesting, gray water reuse, wastewater reclamation and groundwater recharge. Internationally, green in frastructure is commonly used as stormwater treatment measure in many countries, such as American, Germany, Netherlands and Australia. At the same time, m any countries have designed new

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22 approaches to combine green infrastructure and stormwater management f ramework to minimize impervious cover and maximize the infiltration of rainfall. These approaches are also encouraged to be spread out widely in China. However most Chinese research focus on flood prevention and emergency management, but lack of any approaches to solving flood problems before they break out. Thus, the analysis to evaluate the current stormwater management system is of great value to make an improvement of current system. Green Infrastructure Benefits In 2007, EPA commits published a document with information and case studies about the green infrastructure. It aims to increase the development and the use of green infrastructure in water program implementation. Green infrastructure can not only reducing the volume of sewer overflows and run off, it also has a range of environmental and economi c benefits for water quality and quantity. Here are some benefits has been concluded (EPA) . Flooding Control Green infrastructure can reduce flood risk frequencies by slowing and reducing stormwa ter discharges. Green space and varieties of plants are the natural way to reduce the volume of stormwater runoff. Water resource reuse Green infrastructure used for water harvesting and infiltration can increase the efficiency of the water supply system. As the collected rainwater can be used for outdoor irrigation and daily life, the demand of municipal water supply can be reduced. C apturing and reusing water systems like green roof s , rain gardens also can reduc e the demand of water s upply. Enlarge the vegetation coverage allows stormwater infiltrate

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23 the soil and recharge the groundwater to ensur e adequate water supplies for ecological st ability. Water quality control Green space s and varieties of plants are the natural way to reduce t he volume of stormwater runoff as well as polluted overflow from the sewer system. Some green infrastructure like rain gardens or bioretention can filtrate and absorb the pollutants through the micro organisms and aquatic plants . Functional L andscape Green in frastructure integrated with landscape design can improve the urban aesthetic and provide an ecological environment for wildlife. In addition, it can also create various kinds of recreational areas for residents. U rban heat islands leads to r is ing temperatures , particularly in the summer, result in a bad effect to the environment uch as the increased energy consumption; elevated emissions of air pollutions and greenhouse gas s es; compromised human health and comfort ; and impaired water quality (Jane McGrath , 2014 ) . While green infrastructure measures can moderate this issues by creating shade and limiting impervious surface . By decreasing the amount of heat absorbing materials to reducing daytime surface temperature. Trees and vegetation can also improve the air quality through aerobic capacity. Besides, plants can also help to reduce the frequency of respiratory illness. Cost Saving Green infrastructure can be a cost effective ap proach to reduce stormwater runoff . Green infrastructure may save the costs of building large collection and conveyance system, digging gutters and big tunnels, operating and maint ain expenses for the sewer

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24 system and pipes. In addition, this ap proach can also save the cost of repairing th e destroyed infrastructure caused by stormwater. Until now, U.S. EPA commits using a website and the action strategy document to communicate and collect new strategies for green infrastructure improvement. Different organization s have joined together to form a federation, including the Office of Water, the Natural Resources Defense Council, the National Association of Clean Water Agencies, and the Low Impact Development Center. Stormwater Management in American To reduce the impact of stormwater runoff, in 1987 the United States Environmental Protection Agency has implement the policies of Clean Water Act (CWA) to restore and maintain the chemical, physical, and biological in waters. P reventing pollution so urces, providing assistance to wastewater treatment systems and maintain wetlands, CWA has made a big difference to discharge stormwater runoff. Consequently, many communities have installed stormwater management practices in order to reduce the volume and remove p ollutions of stormwater runoff. Stormwater Management in America solve the problem of degradation of ecosystem structure, Low Impact Development (LID) and best management practices (BMP) are the main strategies to create a healthier aquatic environment. Low Impact Development (LID) Low impact development (LID) has been defined as " development which through its low negative environmental impact either enhances or does not significantly diminish environmental quality". ( Maxe y, Larch. December 2012 ) LID is an approach to protect ing or reinstate the natural, re develop ed land and manage stormwater close ly to its source. By using landscape practices and design approaches that infiltrate, filter,

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25 store, evaporate, and detain runo ff close to the source, LID is aim ed predevelopment hydrology and preserve natural drainage features. There are some principles of LID such as preserving and recreating natural landscape features and treat stormwater as a resource rather than a waste product (Unified Facilities Criteria, July 2015) . In these ways, LID can reduce the possibility of storm water pollution in new construction projects and to make earth development more eco f riendly. LID has been adapted to a range of land use , it can be appropriate to new development, redevelopment, or as retrofits to existing development. There are many practices that have been suppor ting the principles such as bioretention facilities, rain gardens vegetated rooftops, rain barrels, and permeable pavements. Green infrastructure used in the neighborhood landscape scales can improve the traditional stormwater measures to support the principle of Low impact development (LID). Best Management Practices (BMP) In the United States , Best Management Practices is known as the main control measure to reduce pollutions from urbanization. BMPs are intended to prevent, control or treat stormwater and imp rove stormwater quality as it moves into streams and rivers United Stated Environmental Protection Agency . It is a type of water pollution control to reduce or eliminate the contaminants collected by stormwater because it will be more difficult and expen sive to restore the pollutants presented in a water body. The treatment which can collect and treat runoff usually compose with fertilization, detention, retention, and infiltration. Most of the BMP are stormwater wetlands , ponds , grassed swales, green roo fs, infiltration trenches and pervious pavements. Environmental Site Design (ESD) Instead of mimic predevelopment conditions and treat ru noff close to the source, environmental site design is focus on managing large volumes of polluted stormwater along the whole stromwater flow. ( Environmental Site Design, 201 1) T he Stormwater

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26 Management Act of 2007 (the Art) using small scale stormwater management practices, nonstructural techniques, and better site planning to mimic natural hydrologic runo ff characteristics and minimize the impact of land development on water resources 1. Becoming better stewards of natural features like drainage patterns, soil, vegetation and minimizing land disturbance. 2. Minimizing and disconnecting impervious surfaces (pav ement, concrete channels, and roofs) .3. Using vegetated channels and areas to treat stormwater, slowing down runoff to maintain discharge timing and to increase infiltration and (T he Art, 2007) . Water Sensitive Urban Design As the hydrological effects of urbanization lead to waterway degradation by erosion and deteriorating water quality during the storms. Water Sensitive Urban Design is another main measure in A merican to mitigate these impacts . It is about integrating water cycle management into urban planning and design (Melbourne Water , 2013 ) Water Sensitive Urban Design is one of the successful strategies that can alleviate heavy environmental pressure from urbanization. Firstly, the main p rinciple of WSUD is to calculate stormwater and reuse it as water resource to relieve water scarcity. Secondly, i n order to achieve resource efficiency, it can integrate stormwater BMPs into the landscape design. This can increase the water quality before it pollute the nearby lakes and reduce the volume and frequency of storm water. Thirdly, it also has mul iple benefits such as alternate supply, improve d amenity and enhanced natural features such as rivers and lakes. On the other hand, WSUD also takes some measures to minimize the drainage inf rastructure development costs b y reducing pipe sizes and potentially use local measures to replace the large scale water systems. There is a range of WSUD measures such as grass swales, bioretention devices and construc ted wetlands that can reduce stormwater flows and remove pollutants prior

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27 to discharge to the environment. The stormwater pollutant s can be addressed adequately through some treatment processes such as physical screening, filtration, and enhanced sedimenta tion. For example, making use of green roofs and Bioretention facilities can control the water flux; grassed swales contiguous streets and retention basins to parking lots can filter water before it runs into the river directly . Besides, ecological buffers along river and lake edges can encourage ecological restoration and improve surface water quality. Here is some treatment for stormwater management . Table 0 2 treatment for stormwater management of WSUD (Source: Melbourne Water) Approach Main function Swales Linear depression channels; Collect and convey stormwater Infiltration trenches Excavation filled with porous material, Collect runoff Gross pollutant traps Use phyical processes to trap solid waste Bio retention systems (Rain g arden) Pond and filter stormwater Constructed wetlands A natural way to treat stormwater before it enters creeks, rivers and oceans Porous paving Filtrate water back to the drains and infiltrate water into groundwater Rainwater tanks Source of domestic water supply for isolated properties and small communities United State Environmental Protection Agency (EPA) Stormwater Management Programs There are some programs in U.S. aim to building long term solutions to redu ce the impacts of worsening air and

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28 empower states, communities, and other stakeholders in economic redevelopment to work together in a timely manner to prevent, assess, safely clean up, an d sustainably reuse brownfields Lala Ma, and Christopher Timmins, June 2012). financial and technical assistance for brownfield where may exist ing in a hazardous subs tance, pollutant, or contaminant . The main principle of using green infrastructure for brownfield sites is not just complete infiltration, but also treat and store st ormwater. Because direct ly infiltration on a brownfield site may cause secondary pollution to groundwater and nearby surface waters. However, green infrastructure is the reasonable choice to retain, treat and finally drain away water without polluted. The treatment process is in tw o steps: The first step is to keep existing trees on the site, minimizing the water infiltrate area s , and planting more trees and vegetation on th e site. Trees and vegetation can be help ful to infiltrate stormwater runoff and reduce the volume of overflow runoff. Buildings and other impervious surfaces ar e act as caps upon the contaminated area. Above the cap are the soils and vegetation that can filtrate stormwater without exposing the water to contaminated soils. The second step is to integrate stormwater reuse system with buildings and surrounding areas. Green roofs are an ideal approach to collect water while reducing the runoff from building roofs. Stormwater can be captured and reused for non potable water in the neighborhood. F or example, stormwater captured in rain barrels of green roofs, rain gardens and bioretention can used for toilet flushing and irrigation. Therefore, the Brownfileds Program create many benefits for local communities. On h EPA Brownfields dollar and 7.3 jobs leveraged per $100,000 of EPA Brownfields funds expended on Assessment, Cleanup, and

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29 (Brownfields and Land Revitalization). And it is also contribute to residential property values and area wide planning. Plan East Tennessee (PlanET) Plan East Tennessee (PlanET) is a regional partnership of East Tennessee Communities from Anderson, Blount, Knox, Loudon, and Union countries that aim to protect our valuable resources and create long term solutions for inve stments in our region. Facing the challenges of our roads, housing, and the environment, the PlanET Demonstration Projects offer some useful strategies to create a clean environment and healthy community ( PlanET Playbook ) . Plan ET is designed to: Seek ideas about protecting our valuable resources and address the environmental challenges. Find the strategies to reduce the polluted water and air, to ensure that we have air that is safe to breath and clean waters in which we can swim and fish. Maximize the value of our current infrastructure investment and minimize the cost. Create a community to make a positive impact on the overall health in the region while reducing public and household health related costs. Plan ET h as played an important role in the long term health of the environment. With the development of the land with paved surfaces, the polluted runoff would enter waterways and increased cases of gastrointestinal illness and parasitic infections. To address the issue of stormwater runoff, acres of new parking lots, rooftops, and other impervious surface were built within a ¼ mile of a situation impaired stream. Water Sense Water Sense is a partnership program of United States Environmental Protection Agency (EPA) to help us protect the water supply by efficient water use. As a

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30 considerable amount of energy used to deliver and treat water, save water also means to save energy and money. Furthermore, water efficiency also benefits for environment protection. Wa ter Sense has helped consumers save a cumulative 757 billion gallons of water and it means that more water available in the lakes, rivers and streams that necessary for human life and wildlife. Improving water efficiency reduces operating costs (such as pu mping and treatment) and reduces the need to develop new supplies and expand water infrastructure. One of the programs of Water Sense is The Lake George Association (LGA ) that to protect Lake George. It the oldest lake association in the United States that lasting for 125 years. The program contains the Floating classroom, Educational outreach, Lake saving projects, Citizen Science and Invasive species. The LGA take some balanced xceptional water quality, to protect the environment and the economy at the same time. Stormwater Management in China In most of the residential communities, the gr a y infrastructure directly discharge s stormwater runoff from sewers into bodies of water . Th is stormwater drainage system was designed by traditional processes and methods such as sewers, impermeable ditches, and pump stations cause water pollution, flood disaster , and eutrophication. From the natural hydrologic cycle, runoff can discharge th rough various effective means, including storage, detention, infiltration and evaporation for cleaning. As a result, the main consideration of a comprehensive stormwater management system is a local hydrologic process and human living requirements. The low impact development (LID) and green stormwater infrastructure (GIS) could satisfy the requirements above and effectively a ddress water environmental issu e s caused by traditional stormwater system (Prince George's County, 1999). H owever, it still a big chal lenge in China to

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31 provide a comprehensive and cost effective solution to plan, design and construct these innovative technologies. As flood disasters result in serious losses in China, the causes of urban floods is a necessary ingredient to find out the improvement measures to the current insuf ficient drainage infrastructure. There are some main causes of urban flooding in China: Climate Change From the research in the past few years, climate change has a critical influence on the changes in flo od frequen cy and severity. Climate c hange ha s led to the increase in the total rainfall from heavy precipitation in most areas. Furthermore, it also resulted in the increase in the amount of rainfall maximum and the decrease in the rainfall duration. (Schreider et a l., 2000). In the recent years, extreme rainfall events have occurred frequently, especially the high intensity but short duration rainfall events (Ding et al., 2006). Moreover , there is a trend of increasing rainfall intensity in the rainy season. Therefore, it will be a big challenges for an urban drainage system in the future. Urbanization China is experienc ing rapid urbanization with the increased industrialization . Meanwhil e, human activities associated with urbanization have significant influence to the hydrological characteristics of nature environment. Besides it is also led to a series of problems such as floods, water shortage, and pollution. When it is flooding, the in creasing percentage of impervious surfaces result to the increase in runoff volume and the reduction in the time to peak and a consequential increase in peak runoff (Liu et al., 2012). Taking Wuhan as an example, with the growth of the urban area of Wuhan from 1990, the constructed area (included industrial grounds, warehouses, transportation

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32 corridors, living quarters and other occupied areas) have increased by more than 20% during the five year period during the period of 1990 1994. However, the land use area for watershed and forest were dramatically decreased. The main reason for the decrease in waterbody may attribute to the water po llution and water shortage after that lakes divided into some water bodies into smaller ones. (Wuhan Environment Profile , 1996 February ) The Lagging Drainage S ystem D evelopments The basic drainage infrastructure in China is not well developed though th e pace of economic growth is rapid. The insufficient infrastructure includes the urban stormwater conveyance systems and flood control facilities. One of the report by Huang and Xu (2006) confirm ed that only a few cities in China such as Shanghai, Shenyang, Changchun and Harbin are equipped with drainage systems that can handle stormwater flow equal to or larger than 100 years Average Recurrence Interval (ARI). From 88 Chinese cities, only 21% of ci ties are installed with drainage systems with the capacity to handle stormwater flow less than 10 year ARI while 18% of cities are with the capacity to handle stormwater flow larger than 50 years ARI. This research show s that the stormwater drainage system s built in the past are proving to be deficient in managing current climate events, especially the extreme storms. Inadequate Urban P lanning With the rapid progress of urbanism f rom 1999 to 2012, urban residential construction area in China have increas ed from 476 × 10 6 to 790 × 10 6 m 2 . As a result, some low lying areas which are sensitive to natural disasters also been developed. For example, Bazhong, Sichuan Province has occurred serious flood disaster on June 30, 2015, which cause 2.7 million people a ffected by the disaster.

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33 Not only caused by the continued rains, another factor was that this town is located beside a mountain. So unconsolidated materials may drop off from the hillslope when the extreme rainfall occurred. Then these materials moved downstr eam as a mud flow and would be aggravated by urban development that had t aken place along the hillslope. Policies, Legislatures on Flood P rotection in China To address the critical flood situation, the St ate Council is th e top decision making organization and assume the whole responsibility. The flood control headquarters rely on China Water Law , China Flood Control Law , China flood protection regulation , China river management regulation , Reservoir and dike safety regulation , Guidelines for the safety construction within retention areas, Plan for extreme flood events on important rivers . (Cheng et al., 2004: 29, Wang, 1999) that encourage the collection, development, and utilization of sto rmwater . S ome large Chinese cities also built stormwater management reuse systems and established relative policies. Onsite and N eighborhood S tormwater Control Measures In the past two decades, with floods has attracted the most public attention, there has been a large amount of research about management practices in stormwater management . A ll these practices are adopted ty the NRC urban stormwater report, s ). For the purpose of repair the water recycle, there are two basic tasks of the stormwater management. Firstly, integrating green infrastructure measures with site design to prevent the stormwater runoff. Secondly, utilizing some structural measures to relief proposal problems. Manage runoff close to the source is one of the no structural methods of stormwater management. As s tormwater characters will change with the damage of the

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34 site con d itions, the natural resources and man made structure are two influence factors of runoff so urce. Compare to the technologies used for the stormwater (infiltration, storage measures) control , n atural discharge are the main facilities to eliminate rainwater runoff. In a word, prevent the natural resources and control the influence of the development are the main strategies to maintain the hydrological functions. The stor mwater control measures include structural controls and bioengineering techniques designed to prom ote natural water cycling processes by harvesting, infiltration, filtration, and conveyance (John Randolph, 201 2 ) . Here are some example of BMP including green roofs, green parking, swales and bioretention areas. Stormwater Storage This area is to con trol runoff rates and settle though temporarily impound runoff. It can also retain stormwater dregs and related pollutants by the construction of bioretention, rain gardens, and stormwater wetlands. Green Roof Green roof is a useful strategy to reduce urban heat islands in communities. A green roof is a vegetative layer grown on a rooftop, vegetation on the roof can shade surfaces and remove heat from the air through evapotranspiration (U.S. Environmental Protection Agency, 2008) . Most U.S. citie s especially large cities have significant op portunities to install green roofs for heat island mitigation. Extensive and intensive are the two basic type s of green roofs. The e xtensive green roof has a relatively shallow soil base, as simple as a 2 inch covering of hardy groundcover. The conc ept of this green roof is need little maintenance or human intervention once it is established. While the Intensive green roofs are more like a conventional garden with no limit on the type s of available plants, including large trees and shrubs. These roofs can not only save energy but also can provide a garden environme nt for the building occupants and the gene ral visitors.

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35 Adapt to the specified type of green roof, the layers of a green roofs are varied. Ge nerally, on the top of the roof deck is insulation layer and above this will be a waterproof membrane, a root barrier, a drainable layer, a filter membrane, and finally growing media for the plants. The waterproofing is located at the structural surface wh ile drainable insulation plans are common ly used on the surface. One of the benefits of green roofs is to enhance stormwater management and water quality. The plants and growing medium of a green roof can absorb water and reduce stormwater runoff in th e urban environment. Study shows that extensive roofs can capture between 50 and 100 percent of incoming rain. The amount of rainwater capture by the green roof depends on the roof slope, the amount of growing medium used, the density of vegetation, the am ount of growing medium used, and the frequency of local rain events. On the same conditions, an intensive green roof will capture more rainwater than an extensive water because of the thicker layer of growing medium. Green Parking Green parking lots ha ve become new landscape s in the urban area with automobiles are become the necessities of life. Most par king lots are made of pavement with impervious, heat absorbing material s, which are a combination of asphalt concrete and aggregates such as sand, gravel, or crushed stone. Stormwate r can not filter into the soil, as a result, runoff may contain many types of fertilizers, pestic i des , and any other pollutants from parking surfaces. Green infrastructure used in the parking lots represents the progress to minimize the e nvironmental impact s of runoff, lo wer site development costs and improve aesthetics. The overarching concept of Low Impact Development (LID) is to involve the stormwater management strategies with the pa r king lots design. Green pa r king use many green infrastructure to manage stormwater on site, such as reduce negative impacts on receiving waters and decreasing the need for costly infras tructure. T hese

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36 green infrastructure for stormwater management on a small scale can develop the site wi th a minimal impact on ecological and hydrological environment. Furthermore, these control measures can maintenance costs by 25 30 percent compare to traditional approaches. Infiltration M easures As water permeate soil, pollutants can be removed by the bi ological action. Between the bottom of the struct u ral and seasonal ground water levels, these systems with deep permeable soil at separate distances of at least 4 feet. Previous Pavements Previous pavements are paved surfaces that can infiltrate, treat and s t ore rainwater. Using pervious concrete, porous asphalt, permeable interlocking pavers , and several other material s, pervious pavements are the cost effective way to solve the flooding problem. There are some voids in the permeable pavement filled with s and, gravel, or soil that can allow stormwater to infiltrate through the pavement into the underlying soil. During rainfall events, previous pavements can infiltrate water and decrease direct surface runoff. Conveyance M easures T he traditional way to c onvey and discharge water is through drainage channel under the ground . While, sustainable design encourage to use nature drainage such as swales and curb extension bioretention swales. Water flows with gravity through nature drainage into storage and infi ltration control measures. Bioretention Swales A bioswale or vegetated swale is a form of bioretention used to partially treat water quality, attenuate flooding potential and convey stormwater away from critical infrastructure (Florida Field Guide to Low I mpact Develop men t , 2008 ). It is a broad,

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37 shallow channel with vegetation covering the side slopes and bottom. The filter bed is the primary component of a bioretention practice with sand, soil and organic material. Bioretention swales can serve as part of the stor mwater drainage system, stormwater can be collected in temporary ponds, and then rapidly filter through the soil. Besides, filter bed can increase infiltration and underground recharge. Bioswales are often designed with parking lot or parallel to r oadways with low er flow and smaller populations. Th erefore, swales are best suitable for residential area and can replace curbs, gutters and storm sewer systems. Filtration M e asures Vegetation or sand are used to filter and settle the pollutants in the filtration media before runof f flow into streams, drainage channels or other water bodies, evaporated or percolated into the groundwater. Besides, in the biore tention or rain gardens, t he infiltration , and treatment system s ma y also occur in the subsoil. Rain Gardens Rain gardens, also called as bioretention or bio to collect and absorb runoff from rooftops, sidewalks and stree t (EPA , 1999 Septemb er consist s of grass buffer strips, sand bed, ponding area, organic layer or mulch layer, planting s oil, and plants. Firstly, storm water pass ed through a san d bed to slow down, then it would be distributed along the length of the pon ding area. The ponding area is graded by surface organic layer or ground cover and the underlying planting soil. Water can be collected to a depth of 15 centimeters and gradually treat ed by the bioretention area. While, the excess runoff would be diverted away. To meet more specific needs, basic bioretention design also modified to include an underdrain within the sand bed to collect the infiltrated water and discharge it to a

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38 downstream sewer system. In this way, the bioretention area acts more as a filter to discharge treated water than as an infiltration device. Bioretention is an ideal stormwater management BMP at residential areas. It can be used in parking lot islands, swales or along the road. Bioretention provides runoff treatme nt area to improve the quality of downstream water bodies. Water can be temporarily stor ed in the BMP and releases over a period of time. Furthermore, it also has a function to provide shade and wind breaks for the neighborhood, have aesthetic benefits to the landscape and conserve biodiversity to the environment. Integral S tormwater M anagement M aster Plan and Design in a C ommunity One of t he goals of stormwater management in the neighborhood is focus on conserving every drop o f water and putting it to use when regenerating a landscape naturally in balance with the climate and rainfall. This system should be carefully designed to create a more natural hydrological system, where rainwater flows will recharge the neighborhood while significantly increase urban biodiversity. To integrate stormwater management into the master plan is a sustainable and economic way to improve the drainage system and reduce the irrigation water demand Rainwater can be collected as recycled resources. The collected water m ay be used for landscape irrigation, groundwater recharge, and road cleaning. If gray water release d into the rivers or lakes, nutrients in the water will bring eutrophication, but they are benefits to plants with valuable fertilizer. So collect and trea te d gray water not only reduce the chance to pollute local water bodies but also can be treat ed a s a water source for landscape. Though the hydrologic data of the community , t he study will integral stormwater management into the mas ter plan to manage runoff and other water bodies for

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39 landscape. Here is the process to using GIS for stormwater managem ent system in the neighborhood (Wu Che, et al., 2013) . Using Landscape Elements and Site Conditions to Building a Multi functional Storage System Along with the stormwater management system, the water movement will form a waterway network, leading from roofs all the way to the lake. Most of the rainwater is intended to travel from roof downspouts to biogutters, then flow in to a large series of bioswales and a seasonal stream before discharging in to a wetland or pond , which finally outflow to the lake. Swales and series of ponds are located on both side of the road, which also can convey water. Permeable paving that installed at the alley streets and parking lots will allow rainwater to infiltrate the ground. The multi functional landscape design will feature rainwater runoff treatment system as an excellent design feature. A series of landscape elements including green roofs, b ioswales, rain garden and wetlands can filter rainwater before disch arge into the nearby rivers. Additionally, ac cording to the different storage function , the multifunction storage system with landscape elements can divide s into control stormwater runoff tank, water recycling tank, and rainwater reuse tank by different functions . For example, t he control stormwater runoff tank can slow down the flow of the river, store rainwater, reduce the flood peak discharge, and recharge the underground water. General ly, the designed rate of discharge is almost the flood peak discharge flow rate in the last 2 to10 years, so the discharge flow rate can control the stormw ater disaster in hundred years. Building a Recycled and Reused Water System The next step is to calculate the volume of non traditional water resources. Through the harvesting measures of green infrastructure and BIM, such as rain garden and rainwater storage tank, water can be calculated more effectively. Community gray water

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40 was collected, treated and reused as a water source for waterscapes. The collected water may be used for landscape irrigation, groundwater recharge, and road cleaning. According to the average annual rainfall, evaporation and other hydrologic data, this research draw a conc lusion of annual water balanc e as the table below (Fig ure . 0 1 ) Furthermore, consider the precipitation changes all the year round, especially in wet season and dry season, the mean monthly water balance data can be more precise instruction for the green building and lan dscape design in the community . Figure 0 1 t he comprehensive water balance chart in the communi Integrating Dispersed and C entralized GSI Differen t kinds of disperses GSI connected together to build the comprehensive stormwater management system, each approach must be carefully selected. Through dispersed GSI (such as green roofs , bioretention, rain gardens, e t . ), most runoff from the community roof could be initially flow e d to the bioretention system. And then collected and conveyed road runoff to Lake through swales along the two sides of the road. The filtrated water will finally discharge to the centralized GSI, like wetland, landscape water, and storage tank.

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41 CHAPTER 3 METHODOLOGY This study focuses on solving urban waterlog problem in Wuhan, seeking to develop a stormwater management system by integrating green infrastructure and landscape elements in the neighborhood. I n order to evaluate the current stormwater management system , I chose a community in Wuhan as the study object . This community has already use d some green infrastructure and water recycled system to managing stormwater. Data is collecte d through interview, online questionnair e and archival research. After the evaluation, I will put forward some relevant improvements to the stormwater management in Wuhan. As one of my classmates has taken part in a community program with green stormwater infrastru cture , I interview ed him and 3 of his colleague s who also stormwater facilities experts in this community water management program. I got the basic information about this project including basic data about the community, and some hydrologic information including the volume of landscape water, water consumption volume in one family, how much recycled water can be collected and how much w ater used in irrigation . These d ata will be use ful to calculate the water balance. T hen w ater balance can help us evaluate the ability of green infrastructure for flood control and water resource reuse system . infrastr uct ure development in this community . All questions in the online questionnaire seeking to cover three general aspects: the ability of GSI to purify water, to improve the living environment, and the economic and practical aspect . Details about these data sources and the data collection proce ss are given in the next section .

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42 The second data source comes from archival research about three community based highly recognized projects. Study of stormwater management systems in these three projects will cover aspects including the policies that encourage the use of green infrastructure, the way to apply green infrastructure, and the benefits of green infrastructure . Based on the analysis of the data sources, my research could find out a reasonable way of applying green infrastructure to the stor mwater management system. Research Approach: Evaluation Framework Through the analysis of the stormwater management system in different programs, this study developed its own evaluation indicator. The evaluation indicator is designed to analyze plans i n five aspects based on the benefits of stormwater : the ability to control flood , to reduce the demand of water supply, to purify water, to improve the living environment, and the economic and practical aspect . The flood control ability and water resource reuse system in green stormwater infrastructure can be evaluated from water balance w hich can be calculated by hydrologic data of the community. Besides, t he ability to purify water, to improve the living environment, and the economic and practical aspect of green infrastructure could be evaluate d the stormwater management system from the online questionnaire . And here is the way to ev aluate these indicators: Flooding C ontrol : C omparing the runoff volume before and after the application of green infrastructure Water resource reuse : To evaluate the water harvesting and distribution works of green infrastructure. Which can be calculated by hydrologic data of the community Water quality control : Compar ing the quantity of water volume before and after GSI filtration. Functional landscape : To evaluate the stormwater management system in accordance with greening and beautify the environment.

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43 Cost saving : To evaluate how much money are used to build the green infrastructure and their future cost of saving. Here is the evaluation framework (Fig 2): Figure 0 2 t he evaluation framework

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44 S tudy O bject : A C ommunity in Wuhan The study select s a community near the Tangxun L ake which using GIS to mana ge stormwater . T angxun Lake the biggest lake in Wuhan . It is the popular tourist attraction with the total area is about 47.6 km 2 (Figure 0 3) The size of the community is about 20.1 hectares, with building land area 4.2 ha, public green space area 7.4 ha, water body area 2.1 ha, the average depth of about 1.0m, the impermeable pavement is about 1.8 ha, and squares area are about 4.5ha. The proje ct encompasses construction space of 353800 square meters with 296800 square meters above the ground (Figure 0 4) . The community has been a division into 3 districts by the pavements. There are three building types, High rise residences in 41 floors or 28 floors and 6 floors multi story building. About 1800 house holds and 7200 people live here . As the community near the lake, i n the rain y season, the weather would so the survey of this community is very useful to my r esearch. Here is the basic data and the hydrologic data of the community: The size of the community: 20.1 hectares, Building land area 4.2 hectares Public green space area 7.4 hectares Water body area 2.1 hectares The average depth: about 1.0m The impermeable pavement area: 1.8 hectares Squares area: 4.5 hectares Construction space: 353800 square meters (above the ground 296800 square meters) Building Types : High rise residences in 41 floors or 28 floors, 6 floors multi story building Green Spa ce: 54388.8 m 2 Residents: 1800 households, 7200 people Hydrological Date: T he average rainfall capacity in Wuhan: 1260mm E vaporation in Wuhan : 1494mm The average reuse d water volume of one person: 62.1 L /day

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45 The average rainfall capacity in Wuhan: 1260mm Water consumption for irrigation: 1.5L/ (m 2 one time) Water consumption for roads and squares: 1.2L/ (m 2 one time) The average runoff coefficient Infiltration coefficient of the clay in the waterproof layer: 1×10 6 mm/s Water Balance C alculation in t he C ommunity Water balance is a useful evaluated method and this study use it to evaluate the flood control ability and water reused system in the community. Water balance is to maintain the water flow in and out of the water system. Through the data analysis of w ater balance , we can manage water supply more reasonable and predict where may be water shortages. It is also contribute to manage irrigation , runoff assessment , flood control , and pollution control ( Wikipedia) . By using LID/ GSI approaches to integrating reuse of non traditional water resources, community gray water was collected, treated and reused as a w ater source for landscape water. This is the basic flow diagram of reused water res ources in the community (Figure 0 5) . Reuse water Figure 0 5 Flow diagram of reused water resources harvesting in the community Water balance in the community is to maintain the water supply with water use and water loss. The water balance calculating is through a serious of calculation to Reused water in the buildings Pretreatment Infrastructure Dispersed GIS Storage tank Precipitation Advanced treatment Centralized GIS (wetland,waters cape)

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46 determine the optimum design. T he analysis process is from the chart below (Figure 0 6) : Ca lculate Water Use and Water Loss The collected water w ould be purified by th e stormwater treatment facility. After that t he recycled and reused graywater can used for landscape irrigation, car washing and roads and squares washing and so on. While th e recycling water pipe system in the buildings are not complete residential, and other u ses (such as shows, toilets, etc. ). The water consumption is based on Building W ater S upply and D rainage D esign S pecifications GB50015 2003 local hydr ological and geological data determine the green building and landscape water infi ltration and evapotranspiration. Water balance should be calculate d every month as the water dema nd is varies every season s . Q W ater Use and Water L oss = Q U se + Q Evapotranspiration + + Q R unoff Q U se = Q I rrigation + Q C ar washing + Q R oads and S quares W ashing Calculate water supply The main w ater supply is from rainwater and gray water of green building s . While the uncertainty of rainfall each season, the high capacity of landscape water can adjust the volume of reused and recycled water from the buildings. As rainwater quality is better than gray water, it is the best choice for water recycle. Here are the simple way to calculate the rainfall capacity: V= H F 1 0 V ---The volume of rainwater storage tank, m 3 ---Runoff coefficient H ---Ranfall, mm F ---Catchment area, hm 2

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47 Except the water loss, gr a y water can be filtrated through a series of treatment infrastructure s before r euse . Therefore , rainwater will be reused for water supply p rior to gray water. The valuable volume of gray water is relatively stable. The water supply of gray water is decide by how many rainwater will be reused in the community. Q Available Water Supply = Q Precipitation +Q Water Recycled or Reused Graywater Water balance is to calculate the difference between precipitation and water demand. If the number is positive numbe r, it means rain water can meet all the water demand in the community, so it recycled water collected from building s because to purify the gr a y water from building s will take long er time and not particularly economical . Furthermore, t h e excess water would be stored in storage tank before overflow. However, i f the number is the negative number, it means inadequate rainfall and more water are needed to be harvested from the green building s . The water in the storage tank can be used for water supplement . The gr a y water can also reuse for non potable water after the treatment facilities . This is the way to calculate water balance Q Water B alance = Q Precipitation Q Water Use and Water Loss Runoff volume is to calculate the difference between water harvesting and water distribution, c omparing the changes of runoff volume can evaluate the flood control ability of GSI and the integrity of the water source reuse system. Q Runoff = Q Water S uppl y Q W ater U sed and W ater L oss Questionnaire From the research , data collected from attribute to the existing drainage system the cost of green infrastructure, and strategies to green stormwater infrastructure improvement .

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48 A survey was designed to select 6 0 0 people of in the community as the data sampling. The questionnaire, with a supporting letter and a reminder , was sent with a prepaid envelope. The letter explain s the objectives and relevance of the study and gave them the option of not participating in the study if they wish. My e mail address was provided in case a respondent has any questions. (Table 4) Archival Research Comparison between green stor mwater infrastructure in United State and China will be performed . The comparative study can draw on experiences in U.S. about use green infrastructure to solve the waterlogging problem . S ince the Clean Water Act in 1972, the stormwater management system in American has made a great improvement with advanced technologies . The strategies and the theories of Green Stormwater Infrastructure (GSI) have p rofound guiding significance to society with Chine se characteristics. The following projects in the United States and China were selected because they have integral drainage system s that have been accom plished for a few years and were still work ing well over time . The research focus on the management policies and approaches used for stormwater management in these some projects as follows. Sino Singapore Tianjin Eco City(SSTEC), Tianjin, China Parkmerced Project, San Francisco, United State s Oriental Sun City Community, Beijing, China For the research, sources of GSI are from their websites and thesis, such as which kind s of green infrastructure they used, t he cost of the water reuse systems and landscape functions of GSI . Furthermore, different opinion s f rom the stormwater facility

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49 specialists worked with these projects also be gathered . After that, comparisons are made of their systems to choose the most suitable one for China. CHAPTER 5 ARCHIVAL RESEARCH Sino Singapore Tianjin Eco City(SSTEC) One of the successful planning case in China Sino Singapore Tianjin Eco City(SSTEC). Tianjin Eco city is a collaborative project between the Chinese and Singaporean government that provide a low carbon, green environment around half the size of Manhattan. Located 4 0km from Tianjin, the project is scheduled to build 100,000 sustainable homes for 350,000 residents b y the time the entire project will be completed around 2020. T he b ig challenges of this project are water scarcity and water pollution due to local clima te and degraded environment of the area. How to deal with these challenged? Sino Singapore Tianjin Eco City using some sustainable approaches to managing stormwater. All the sustainable approaches are under the guidance of Water Sensitive Urban Design , whi ch can alleviate heavy environmental pressure from urbanization. Consequently, stormwater will be calculated and reused as resources to relieve water scarcity. Sustainable Approaches Water Resource Reuse: Rainfall Collection and Wastewater Reuse S ystem Rainfall collection and wastewater reuse system are used to help achieve the objectives. Water consumption limited t o 120 L/day per capita, however per capita comprehensive water consumption has reach ed to 320 L/day. So half of the water

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50 volume must co me from non conventional water sources including d esalination and water recycling (Singapore Government , 2009). Water Quality Control: Variety of Stormwater T reatment and C onveyance S ystem (grassed swale, bioretention swale) One of the principles for W ater Sensitive Urban Design (WSUD) is to capture and treat waste water at source, which can prevent pollutant gene ration, and limit pollutant exposure to stormwater. Through some treatment processes such as physical screening, filtration, and enhanced sedi mentation, the stormwater pollutant s can be addressed adequately. As a result, rain gardens can be utilized to improve the water quality for riparian zones near the significant urban catchment. And stormwater treatment wetlands are one of the large st defenses against pollutants for larger urban catchment. Additionally, tanks and other collection devices also used for rainwater capture in this project . In a word, the main strategies in this w ater quality control system are to control stormwater polluti on s at the source and combine the treatment with the landscape design . Functional L andscape: I ntegrate S tormwater BMPs into t he Landscape D esign In order to achieve resource efficiency, Integrate stormwater BMPs into the lands cape design is one of the economical and practical solutions . I t can create a healthy urban water cycle, enhance landscape esthetic and provide a recreation area for residence. For example, making use of green roofs and bioretention facilities can control the water flux; grassed sw ales contiguous streets and bioretention basins of parking lots can filter water before it runs into the river directly . Besides, ecological buffers along river or lake edges can also encourage ecological restoration and improve surface water quality.

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51 Cost S aving The water recycle system can also save money than traditional stormwater management system. First of all, WSUD takes some measures to minimize the drainage in frastructure development costs by reducing pipe sizes and potentially use local me asures t o replace the large scale industrial materials . Secondly, i ntegrating stormwater BMPs into the landscape design during the planning stages can also improve urban water cycle efficiency and lower the cost to build stormwater treatment system. Park merced Vision Project Parkmerced is a 152 acre residential neighborhood located in the southwest corner of San Francisco. It was an old neighborhood built from 1942 to 1952 with 3221 residential units. Over 20 30 years, the project transform ed the buildi ngs and landscapes into a vital neighborhood with green infrastructure utilized in water management. The proposed topography has been carefully designed to create a hydrology network that can make a connection of built and natural infrastructure. Sustaina ble A pproaches Water R esource R euse: Recycled Water System Water at Parkmerced can be treated as a resource by using the combined sewer system for household sanitary sewage only. Through a combination of green infrastructure including bioswales and other bio filtration systems into the community , water can be collected and restored in the natural hydrology of the site. Besides, recycled water can also providing non potable water uses in buildings , like bioswales, rain gardens and biogutters i the dra inage system .

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52 Furthermore, permeable paving on th e alley streets and courtyards can allow water to infiltrate the ground. In this way, water will be more efficiently used and will be reduced by 50%. The annual volume of water for irrigation, roughly 55 mi llion gallons of potable water per year ( MG/yr), is expected decrease to just over 30 MG /yr due to widely use of recycled and gray water. By using some of the high efficiency water fixtures like: low flow toilets, sinks, showers, and laundry machines in the units; and the use of recycled water for non potable fixtures, the average resid ential water demand use will reduce to 38 gallons per Oceanside Wastewater Treatme nt Facility, which bring about less chemical use, lower energy usage, and few er po llutions to the Pacific Ocean. Flood Control: Storm Drain System The existing storm drain system is a sewer only system conveys both sewage and storm drain flows. Most storm water will conveyed to the waste t reatment plant before discharging in to the ocean. T o make the improvements , the proposed storm drain system is well developed. The bio swales, streams , and ponds would convey most of th e runoff on the ground surface while pipes can convey flows through intersections and across streets at some locations. Besides, there are also a series of detention ponds located throughout the site, which can provide storage and reduce the peak rate of d ischarge from the site. In order to help infiltrate runoff from small storm events into the groundwater, permeable surface have be installed where possible and applicable. Permeable surface appear s in both pedestrian walkways, parking areas , and other low traffic areas. In addition, a stream system was constructed at the southern end of the site. Through the stream, water from the majority of the site is carried to a terminal pond at the southwest corner. Along the stream, some ponds are installed to help store runoff

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53 and slow down the discharge rate. After that, the stream are lined to reduce erosion and protect the existing slope. Water Quality Control and Functional L andscape Some green infrastructure for water management ha ve been combined with the landscape design, including biofilter; b ioswales; a stream corridor, ponds and wetlands. Through this system, water can be filtered and cleaned before discharging into Lack to travel from roof downspouts to gutters, and then into infrastructure report, 2001. 11) Oriental Sun City Community The Oriental Sun City C ommunity is a large scale residential project in eastern Beijing. It has a construction area of 234 ha, 80 ha building area, 16 ha lake area and a 75 ha green space. With the integral stormwater management plan, this site aim s to establish an ecological a nd comfortable retireme nt community. The community plan included three internal lakes for the landscape design. However, it did not to continue the plan because the serious water environment pollution, water shortage , and high maintenance cost. Although th e existing dam was built to withstand the floods, the construction site on the original flood prone area still facing an increased risk of flooding. Besides, the pollutions flushe d into the body of water directl y through the sweater cause serious eutro phic ation . T herefore, the main issue to create an ecological community is to make a better stormwater management system. To find a sustainable, economical stormwater management system that can manage runoff and other water resources, a complex construction workflow sho uld first

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54 conduct. After comparing the economic and technical feasibilities, the plan of the stormwater man agement system was finish ed with some sustainable approaches. Sustainable Approaches Water Resource R euse : Green Stormwater Infrastructure S ystem The master plan of t he site reverses the large amount of green open space, which allows a high percentage of t he water absorbed back into the ground through the soil. On the other hand, most stormwater from the roof would discharge to the bioretention system. Swales are located on both side of the road, which can convey water runoff to the local lake. Furthermore, wetlands and soil filters ar e set in each lake to purify water. At last, all the collected water come together to the golf course for infiltration before flow into the local lake (Fig ure 0 8 ). Application of g reen i nfrastructure Bioretention The main o bjective of green stormwater infrastructure is accomplished to collect, infiltrate and hold back runoff of Oriental Sun City. One of the typical LID approaches on the site is biotetention. It is combined with roof downspout and landscape design. Though the local soil and vegetation, the bioretention can collect and purify stormwater . Swale The stormwater swales are closely related to the landscape design and vertical design in the site. Based on the site terrain, discharge direction and slope requirements, swales are designed along the road to replace the traditional pipes. The depths of swales are nearly 50 to 200 mm, it can convey storm water to each lake. Wetlands W etlands were designed to control water quality with selected vegetation. Depend on the elevation and artistic factors, different plants are planted as natural water purifier

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55 including reed, lotus, and canna. The capability of storage water can be useful for flood control. Flood C ontrol and W ater Q uality C ontrol As the total landscape water area was approximately 18 ha in the site, the waterscapes can be important storage spaces during storm events. The design storm was appro ximately 115 mm in Beijing based on the 24 hour duration storm for a return period of five years. Besides, water flow over the waterscapes was collected and conveyed to the golf c ourse during the extreme storm. Fu r thermore, LID and GSI approaches play an important role to collect and purify the runoff. According to the annual water volume balance analysis of the site, nearly 90% of the runoff has been collected and purified for further use (Tang and Che, 2009). Thanks to the plan and design of gre en stormwater infrastructure in the community, flooding seldom occurs and approximately 60% of the total pollutants could be reduced. Most of the LID approaches was adapted to the landscape design and architecture design. Cost Saving Th e economic rationality of the project has been proven by the actual computation. The total construction cost is almost the same with the traditional stormwater infrastructure by saving costs of stormwater drainage pipe repair and pump stations. In addition , reused water for irrigation and waterscape supplying are nearly 2.7*10 5 tons per year, which equal to more than 1.08*10 6 CNY according to the current water price in Beijing (Wu Chen, Yang Zhao, 2014) . Generally speaking, this case demonstrate that it a c ost effective and reasonable methods to integrate stormwater management planning with GSI approaches in the community.

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56 CHAPTER 6 DISCUSSION AND ANALYSIS Date of Water Balance Through the analysis of hydrologic data and climate conditions in Wuhan, the water consumption of the community can be calculated. Here is the calculating process of water balance: The R euse d Water Volume in t he B uildings According to the water consumption index and way of water use d in the buildings, the average reused wat er volume of one person is 62.1L each day. So the reused water in the buildings is calculate d blow Q Recycled or Reused Graywater = 62.1/d, ×7 3 00 (number of residents) = 453.3 m 3 /d ay =13600 m 3 / mon thly = 165465 m 3 /year The Volume of R ainwater The volume of rainwater is determined by and the rain water capture approaches, the volume of rainwater storage tank, and runoff coefficient. The average r a infall capacity in Wuhan H is 1260 mm . With a survey on the landforms of the community, water can natura lly flow into the waterscape. The catchment area A is 201440 m 2 . The seasonal reducing coefficient is 0.85 and traditional water resource s is calculate d blow: Q Precipitation =0.59×0.85×0.87×201440×1260÷1000= 110740 m 3 / year The Evaporation Volume of Landscape Water The volume of waterscape is 22158.4 m 2, the average evaporation in Wuhan (H evaporation ) is 1494 mm, so the evaporation volume of waterscape can be calculate blow:

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57 Q E vaporation = A waterscape × H evaporation =22158.4 m 2 ×1494 mm=3310 5 m 3 / year The I nfiltrate V olume of Landscape Water The waterscape area is 22158.4m 2 , infiltration coefficient of the clay of th e waterproof layer is 1×10 6 mm/s. Besides, infiltration area is 1.2 times of the waterscape area. So the average infiltration volume in one year is: Q I nfiltration = 22158.4m 2 ×1×10 6 × 3600s/h × 24h/d × 30d/m×12m/y=837m 3 /year The C ar W ashing C onsumption The index of a car washing consumption is 300L/ (number· day), there are almost 2160 cars here w ith 0.6% people will wash cars in the community. The car washing consumption can be calculate d blow: Q Car Washing C onsumption = 0.3 m 3 / (number· day) × 2100 × 0.006=3.78 m 3 /day = 113 m 3 /mouth= 1380 m 3 /year Irrigation W ater C onsumption The green space area is 5646.4 m 2 in the community. Basically, the frequency of irrig ation is one time a day with 1.6 L/ (m 2 ·one time). So the irrigation water consumption is: Q Irrig ation W ater C onsumption = 0.001 6 m 3 / (m 2 ·onetime) ×1time/ day×30d/mouth×12mouth/year × 5646 =3 3252 m 3 /year The R oads and S quare s W ashing W ater C onsumption The water consumption index for roads and squares is 1.2 L/ (m 2 ·one time), and the area of roads and squares is 6 4 000 m 2 Q Roads and Squares Washing C onsumption = 0.0012m 3 / (m 2 ·one time) ×1 time/day× 64 000 m 2 =76.8 m 3 /d =2304 m 3 /mouth=28032 m 3 /year

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58 W ater B alance Water will be collected from precipitation and recycled graywater in the building . The collected water will be used for evaporation, infiltration to the ground and reuse in the community , such as landscape irrigation, car washing and roads and squares washing. In this research, the water use inside commercial, residential, industrial, an d other uses (such as showers, toilets, food produ ction, industrial production, e t c. ) were not included in this calculation, because the transport water piping system is not completed. But in the future, use recycled water in the buildings will encourage w ater efficiency and reduce excess runoff. A water balance can be used to help manage water supply and predict where there may be water shortages . This study uses it to evaluate runoff assessment , flood control . If the water balance is a positive number, it means precipitat ion ca n meet water requirement, and the excess runoff will be stored in the storage tank. The excess runoff volume can evaluate flood control ability. On the other hand, when t he water balance is a negative number, it mean s inadequate water supply and more water are needed. S toring excess runoff in times of flooding or high water availability is a way to reduce water shortage issues in times of drought, and also possibly to reduce flooding issues. So ideally there should be more water storage when the wat er balance is positive to provide water to the community when the water balance is negative. The volume of storage tank is 2100 m 3 (Figure 0 9). Monthly W ater B alance (Table 0 5) Consi der ing the precipitation changes all the year round, especially in wet season and dry season, the mean monthly water balance data can be more precise instruction for the green building and landscape design in the community. In the dry season (such as January ) :

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59 Q Water Use and Water Loss = Q Evapotranspiration + + Q I nfiltra tion +Q Irrigation + Q Car washing + Q Roads and Squares Washing = 727+71+113+1147+1823=3881 m 3 Q Water Balance = Q Precipitation Q Water Use and Water Loss = 8 19 3881= 3 0 62 m 3 <0 T he water balance is a negative number, it mean s inadequate water supply and more water are needed from recycled and reused graywater. The gray water volume is: Q Rec ycled or reused graywater = Q Water Use and Water Loss Q Precipitation = 3881 8 19 =3162 m 3 The inadequate water supply means no excess runoff and no storage water. Q Overflow = 0 m 3 and Q water storage = 0 m 3 In rainy season (such as May): Q Water Use and Water Loss = Q Evapotranspiration + + Q I nfiltration +Q Irrigation + Q Car washing + Q Roads and Squares Washing = 2305+71+113+3441+2734=8664 m 3 Q Water Balance = Q Precipitation Q Water Use and Water Loss = 14953 8664= 6289 m 3 > 0 W ater balance is a positive number, it means precipitat ion can meet water requirement, and the excess runoff will be stored in the storage tank with the volume of 2100 m 3 . No more graywater are needed and overflow will be distribute to the rivers or lakes. The excess runoff will be storage in the tank to reduce water shortage issues in times of drought . Q Rec ycled or reused graywater = 0 m 3 Q Overflow = Q Precipitation Q Water Use and Water Loss Q water storage = 14953 8664 2100=4189 m 3

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60 Table 0 5 Monthly water balance date Annual W ater B alance Calculation (Table 0 6) Q Water Use and Water Loss = Q Evapotranspiration + + Q I nfiltration +Q Irrigation + Q Car washing + Q Roads and Squares Washing = 33105 + 837 + 3 3252 + 1380 +28032 = 96606 m 3 /year Q Water Balance = Q Precipitation Q Water Use and Water Loss = 110740 96606=14134 m 3 /year Q Overflow = Q Actual W ater S upply Q Water Use and Water Loss = 110740+12550 96606=26684 m 3 /year . Water Balance Evaluation Evaluate the F lood C ontrol A bility of GSI In the rainy season, water balance is a positive number . It means precipitation can meet all the water demand need to use recycled water in the building. Runoff can be storage in the tank for the further use and the volume of the runoff are sharply reduced.

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61 In the dry season. The water balance is a negative number . It means nd. More water should be collected in the green building s like green roofs. Calculate the monthly water balance can control flood ing , manage water supply and predict where there may be water shortages. Evaluate the Water Resource R euse S ystem Stormwater c an be calculated and reused as resources to relieve water scarcity. The green infrastructure storage systems like wetlands and landscape water tank can collect more water than traditional tank and save the cost to build and maintain the storage tank. The water harvesting from precipitation and gr a y water can provide non potable water uses in buildings . Date of the Q uestionnaire An online questionnaire was designed to select 6 00 people of in the community, but I only receive feedback from about 150 satisfactory towards water quality control ability, landscape function, and cost saving of green infrastructure. It is including t he background information of the survey people and their satisfactory toward using green infrastructure managing stormwater (Figure 0 10) Data area used to evaluate the water quality control ability, the landscape function, and the cost saving of GSI.

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62 Figure 0 10 b ackgrou nd Information of survey people Figure 0 1 1 a ttribute to the green stormwater infrastructure

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63 Questionnaire Evaluation Evaluate the Control W ater Q uality Most people think the green infrastructure can purify stormwater and restore natural water cycle, however , it is also lake of insufficient engineering standards to evaluate it. Evaluate L andscape F unction It is generally considered that green infrastructure can beautify the living environment. Evaluate C ost S aving Because of the possible financial loss of the unknown and uncertai nti es in trying new infrastructure , most people think the cost of stormwater management practices are much higher than conventional drainage system. Application : O ptimization M easures of GSI in t he C omunity Though the evaluation to t he current stormwate r management system in Wuhan, this study conclude the optimization measures of GSI in the community in the different communities . The community can be divid ed into two types accordin g to the rate of the green rate is greater than 25% or not . Centralized GS I as t he M ain T reatment M easures, D ispersed GSI as A S upplement For the new residential with the rate of the green space greater than or equal to 25%, The centralized green stormwater infrastructural can provide abundant of open space for wate r harvesting and infiltration. So the strategy to this community is to arrange some GIS for st or mwater harvesting like green roof s and bioswales, then convey to the con centrated GSI (rain garden and landscape water body) for water infiltration and recyc led. This is the mode flowchart (Figure 0 12).

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64 Figure 0 12 flowchart Dispersed GSI as t he M ain T reatment M easures For the old district or village in the city with the rate of the community greening less than 25%. The rapid urbanization lead to large population and construction density and small spatial scale. The limited open space and green space make it difficult to constru ct green infrastructure. Besides, the old building structural may hard to construct a green roof on it. According to the green roof standards, the structura l support of the building must be sufficient to hold the additional weight of the green roof, which is typically an additional 15 to 30 pounds per square foot of load for an extensive syst em with a 4 inch growing medium( ASTM International Green Roof Standards , 2014 ). To address this issue, the optimization proposal of this research is to d ecentralize d arrange some small scale green infrastructural like rain harvesting systems , bioswales, rain garden s , and green fields to build a small water cycle system. This is the mode flowchart (Figure 0 13) :

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65 Figure 0 13 Disperse CHAPTER 6 CONCLUSION Impediments of S tormwater M anagement in Wuhan Despite many countries focus on expand green infrastructure use in terms of rainwater , but it still have difficulties in t he implementation. In 2005, the Green Building Practice Study (GBPS) conduct a survey of the strategy use and obstacles in site specific ecological design. The result showed that the main reasons of the green st due to Lake of basic hydrologic data and research gaps exist in theory and implementation; Ineffective integration of

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66 stormwater management to urban planning; Poor operational and maintenance practices and Public participation and public support is insufficient and lack of funding support. In order to overcome the barriers to green infrastructure, it is important to figure out how to implement green infrastructure in China. Based on the research on the policies of stormwater management, the interview , questionnaire and a rchival r esearch of the stormwater management in China, this research conclude s some questions of current stormwater management and put forward some solutions. T his research identifies four major impediments of apply green infrastructu re to stormwater management : Lake of B asic H ydrologic D ata and Research G aps E xist ing in T heory and I mplementation One of the basic factors of successful stormwater management is the detailed knowledge about the stormwater quantity and quality charac teristics in the urban areas. It includes the catchment characteristics and rainfall characteristics that may directly influence the stormwater characteristics. The basic data consist of land use, the current status and distribution of drainage systems and rainfall runoff records which compose a comprehensive database that can provide baseline and essential information to decision makers. However, most of the sophisticated baseline data are not available in a useable form for Chinese decision makers. T he knowledge regarding to stormwater management are significantly restrained. How to ob tain the essential data of urban stormwater quantity and quality is one of the most critical issues for most of the researchers in China. In a word , the lake of the late st information block the way of successful stormwater management. Another big challenge of stormwater manag ement is not practical application to daily life . There is still a gap between the knowledge in the research areas and the

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67 implement of action. The technologies to implement GSI is still imperfections and lack of guidance because sufficient data are not availa ble . More than that , even in the same company the knowledge are not available in different departments. For example, some drainage system de sign drawings are available to the engineering department are not available to staff in other departments. Therefore, the absence of knowledge transfer would significantly influence stormwater management in China. Ineffective Integration of S tormwater M ana gement to Urban P lanning In recent years, with stormwater management such as stormwater reuse and flood ing control have received much more attention in China, some large Chinese cities have built stormwater management reuse systems and established relative policies. For example, by the end of 2006 in Beijing, there are have been more than 100 projects have been accomplished about stormwater management while the number has risen to 450 projects in 2007 (Dong et al, 2007). However, these projects were not ef f ectively integrated into urban planning. As the stormwater management has some inherent relationship with the surrounding infrastructure such as transport systems, land use, and biological environment. It is essential that the stormwater management policy should consider the overall urban design to avoid the negative impact on the urban infrastructure. Poor O perational and M aintenance P ractices Due to the rapid urbanization, more polluted stormwater flow into the urban drainage system. Appropriate operat ional and maintenance practices are the necessary factor s to ensure the efficiency of the stormwater management. During the rainfall issue, the pollutant s which should be transported into the drainage pipeline would be accumulated and plug up the urban dra inage system. The blocked sewer may enhance the potential of flood ing occurrence. So maintain the drainage system periodically is very important to reduce flooding in the urban area.

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68 In the other hand, lake of knowledge on basic maintenance provisions, us eful life for f l ood ing control facilities, life cycle costs and replacement time can influence the effective stormwater management in China. Public P articipation and P ublic S upport is I nsufficient and Lack of Funding S upport Lack of funding is always cited as a barrier to the implementation of green infrastructure. The uncertain or insufficient technologies of green infrastructure are the big challenge s to China. Funding support from the government is very limited to support the running and repairing of green infrastructure, while green infrastructure system is expensive and require investments. In fact, m any people in China are still lack of basic infor mation about green infrastructure, which makes the limited support funding to the stormwater management. To put it differently , the relevant authorities and stakehol ders have the right to be opposed to using what they may consider to be untested technologies and where adequate informati on is lacking (Mc Manus, 2009). Hence, f or the decision maker of stormewater management to gain the trust of relevant authorities and stakeholders is also the big issue. Suggestions to Stormwater M anag ement P olicies To manage runoff and other water resources, the stormwater mana gement system should find comprehensive, sustainable, and ecologically means to solve these complex stormwater environment problems. Here are some suggestions to apply green infr astructure into stormwater management in Wuhan .

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69 Problem 1: Lake of B asic H ydrologic D ata and Research G aps E xist ing in T heory and I mplementation Suggestion s : Establish a stormwater mana ge ment system The government should establish a stormwater management system to connect all the related management departments. In the procedure of green stormwater management system, confirm different responsibilities of the management departments and strengthen cooperation. Improve the existing stormwater inform ation database . Collect ing monitor data, set up and improve the database. All the knowledge should be calculated and valuable to the relevant staff member s . Problem 2: Ineffective Integration of S tormwater M anagement to U rban P lanning Suggestions: In tegrate green stormwater management system into urban planning Stormwater management strategies should consider the overall urban design to avoid the negative impact on the urban infra structure. Strengthen research towards technology and management systems and stormwater pollution control measures. The s tormwater management system should under the guidance of Low Impact Development. To restore and improve local hydrological processes of the site, the green stormw ater infrastructure should minimize the impact to the site condition s . stormwater management should create a natural water system, make full use of the natural green infrastructure like the green roof s , bioswale s , rain garden s , plant boxes and wetlands .

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70 P r oblem 3: Poor O perational and M aintenance P ractices Suggestion s : Integrate green infrastructure into stormwater system planning for new developing area I ntegrate green infrastructure , surrounding environment and landscape elements in the stormwater system design. Stormwater management strategies should consider the overall urban design to avoid the negative impact on the urban infrastructure, strengthen research towards management systems and technologies of green infrastructure. Improve technologi es of stormwater management facilities for built up area Draw lessons from high recognized projects in United Stated, consider ing the environmental, economic and social impa ct of the stormwater system. In the meantime, improve the technologies of stor mwater management facilities to combine sustainable approaches into drainage system reform . To establish a legally binding Inspection and Maintenance Agreement Routine operational managemen t and maintenance can improve public recognition of green infra structure and ensure the proper functioning of the system. Problem 4: Public P articipation and P ublic S upport is I nsufficient and Lack of Funding S upport Suggestion s : Improve the public attention Establish specific policies and funds to improve public attention. Further related research should be encouraged by the government.

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71 Strengthen the public education Establish specific organization to educate people basic knowledge about green stormwater management measures. Disseminate the relative massages through the w ebsite s and recording videos to encourage individuals and enterprises to participate in the construction and maintenance of the gree n stormwater management facility.

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72 APPENDIX Table 0 1 Statistics of th e water levels above 27.30 meters measured in Wuhanguan water station between 1865 and 2003. Source: Wuhan Shuiwuju, 2004 Year Water level Year Water level 1954 29.73 1980 27.76 1998 29.43 2002 27.76 1999 28.89 1935 27.58 1996 28.66 1968 27.39 1931 28.28 1988 27.39 1983 28.11 1870 27.36 1995 27.79 Table 0 2 . treatment for stormwater management of WSUD (Source: Melbourne Water) Approach Main function Swales Linear depression channels; Collect and convey stormwater Infiltration trenches Excavation filled with porous material, Collect runoff Gross pollutant traps Use phyical processes to trap solid waste Bio retention systems (Rain garden) Pond and filter stormwater Constructed wetlands A natural way to treat storm water before it enters creeks, rivers and oceans Porous paving Filtrate water back to the drains and infiltrate water into groundwater Rainwater tanks Source of domestic water supply for isolated properties and small communities

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73 Table 0 3 . Typical green infrastructure approaches from the smaller scale elements to larger scale elements that can be integrated into sites. Approach Main function Related Strategies Downspout Disconnection Store stormwater and allows stormwater to infiltrate into the soil Combine with bioretention, rain gardens Rainwater Harvesting Collect and store rainfall for later use Combine with roof downspout Rain garden Pollution control retention and infiltration Combine with roof downspout Coordinate with landscape design Planter Boxes Collect and absorb runoff Combine with bioswales Bioswales Treat and convey stormwater Combine with planter boxes, permeable pavements, Coordinate with community elevation, road gradient, and lake landscape design Permeable Pavement Infiltrate and treat stormwater Combine with bioswales, green street and green parking Green Streets and Alleys Store, infiltrate and evapotranspire stormwater Coordinate with landscape design, Combine with permeable pavement, bioswales, planter boxes and other green infrastructure features Green parking Infiltrate and treat stormwater Combine with permeable pavement, rain garden and bioswales Green roofs Infiltrate, evapotraspire and store water Combine with roof downspout, rain garden and rainwater harvesting Storage tank S tormwater harvesting and reuse Coordinate with underground space

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74 Table 0 4 questionnaire for the green infrastructure in Wuhan QUESTIONNAIRE FOR THE GREEN INFRASTRACTURE IN WUHAN Background Information Age: below 18/ 18 30 / 30 50/ 50 and above Gender Female/ Male Literacy Levels Below high school level of education/ above high school level education of education How long have you live in Wuhan Less than 1 year / 1 3 years/ 3 5 years/ 5 10 years/ more than 10 years Your attribute about stormwater treatment in Wuhan Is Wuhan had flooding problems? Yes / No / Not Sure Is flooding has the negative effect to your life? Yes / No / Not Sure Do you think urban flooding problems will become more serious in the next few years? Yes / No / Not Sure Are there any stormwater treatment infrastructures in your community? Yes / No / Not Sure Would you like to use reused water in your daily life? Yes / No / Not Sure Do you think green stormwater infrastructure will cost more than traditional drainage system? Yes / No / Not Sure Stormwater treatment can purify water and slow down the release of waste water into lakes and rivers Yes / No / Not Sure Choose some infrastructures that you think can be useful to release stormwater problem? Green Roofs / Green Parking / Bioretention Basion / Infiltration Basins /Planters / Trenches / Previous Pavements / Bioretention Swales Please give some advice to the existing drainage system? Thank you to filling up the questionnaire. Would really appreciate it if you could email this back to me before July 2015 at yingwei@ufl.edu

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75 Table 0 5 Monthly water balance date

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76 Table 0 6 t he water balance chart of landscape water for year (m 3 /y) Water Balance Available Water Supply Water Use and Water Loss Storage tank Overflow Precipitation Recycled or Reused Graywater Evaporation Infiltration Car Washing Irrigation Roads and Squares Washing Volume 110740 165465 33105 837 1380 33252 28032 2100 26684 Figure 0 1 . t he comprehensive water balance chart in the community

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77 Fig ure 0 2. The evaluation framework

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78 Figure 0 3 the community location Figure 0 4 . The community general plan

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79 Reuse water Figure 0 5. f low diagram of reused water resources harvesting in the community Figure 0 6 the water balance calculating analysis Reused water in the buildings Pretreatment Infrastructure Dispersed GIS Storage tank Precipitation Advanced treatment Centralized GIS (wetland,waters cape)

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80 Figure 0 7 t he comprehensive water balance chart in the community Figure 0 8 s chematic diagram of the stormwater management master plan

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81 Figure 0 9 t he detail of non traditional wat er consumption in the community Figure 0 10 b ackgrou nd Information of survey people

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82 Figure 0 1 1 the a ttribute to the green stormwater infrastructure Figure 0 12 Centralized flowchart

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83 Figure 0 13 . Disperse

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84 LIST OF REFERENCES A.E. Barbosa, J.N. Fernandes, & L.M. David. (2012, June). Key issues for sustainable urban stormwater management. Water Research , 46, 6787 6798 Allison H, Roy et al. ( 2008 , August ).Impediments and Solutions to Sustainable, Watershed Scale Urban Stormwater Management: Lessons from Australia and the United States. Environmental Management , 42(2), 344 59 . doi: 10.1007/s00267 008 9119 1 Brad Collett et al. (2013). Low impact development opportunities for the PlanET region, 4(2). 109 144. Retrieved from: http://www.planeasttn.org/DesktopModules/Bring2mind/DMX/Download.aspx?E ntryId=1282&Command=Core_Download&PortalId=0& TabId=143 Environmental Profile of the Wuhan Municipal Area. (1996, February). Wuhan Sustainable Cities Program, Retrieved from : http://www.fukuoka.unhabitat.org/programmes/scp/china/pdf/Wuhan_EP.pdf EPA. (2008, April). Design Principles f or Stormwater M anagement on C ompacted, Contaminated Soils in Dense Urban Areas, Retrieved from: www.epa.gov/brownfields EPA. (2008, April). Case Stu dies for Stormwater Management on Compacted, Contaminated Soils in Dense Urban Areas, Retrieved from: www.epa.gov/brownfields I, Brodie. (2012). Stormwater harvesting and WSUD frequent flow manag ement: a compatibility analysis. Water Science & Technology , 66(3), 612 619 Jone S, Jacob & Riardo Lopez. (2009, June). Is denser greener? An evaluation of higher density development as an urban stormwater quality best management practice, Journal of the American water resou rces association. JAWRA journal of the American water resources association , 45( 3 ), 687 701 Kevin H aninger, Lala Ma, & Christopher Timmins. (2012, August). Estimating the Impacts of Brownfield Remediation on Housing Property Values, Duke Environmental Economic Working Paper Series, Available from Project Brownfields and Land Revitalization Web site: htt p://www.epa.gov/brownfields

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85 LIU An and GUAN Yuntao. ( 2014. March 30 ). Stormwater Management in China: learning from the urban flood disasters . Stormwater Management in China: learning from the urban flood disasters . Retrieved from: http://www.researchgate.net/publication/260126231_Stormwater_management_ in_China_learning_from_the_urban_flood_disasters Marjorie van Roon . (2007).Water localisation and reclamation:Steps towards low impact urban design and development. Journal of Environmental Management , 83, 437 447 Marla C. Maniquiz Redillas, Franz Kevin F. Geronimo, & Lee Hyung Kim. (2014. May). Investi gation on the e ffectiveness of pretreatment in stormwater management technologies, Journal Environmental Sciences , 26, 1824 1830 Melissa Keeley et al. (2013). Perspectives on the Use of Green Infrastructure for Stormwater Manage ment in Cleveland and Milwau kee , Environmental Man agement 51(6), 1093 1108, doi: 10.1007/s00267 013 0032 x Environmental Protection Agency. Office of Water. Washington, D.C. EPA 832 F 99 012. September 1999. Storm Water Technology Fact Sheet Bioretention. Retrieved from: http://water.epa.gov/scitech/wastetech/upload/2002_06_28_mtb_biortn.pdf John Randolph. (2012). Environmental Land Use Planning and Management. Washington, DC: Island Pre ss. Joshua Olorunkiya, Elizabeth Fassman , and Suzanne Wilkinson. (2012 , August 2 ). Risk: A Fundamental Barrier to the Implementation of Low Impact Design Infrastructure for Urban Stormwater Control. Journal of Sustainable Development ; 5,9. d oi:10.5539/jsd. v5n9p27 Plan East Tennessee Communities. (2014). PlanET Playbook . Retrieved f orm: http://www.planeasttn.org/DesktopModules/Bring2mind/DMX/Download.aspx?E ntryId=1402&Command=Core_Download&PortalId=0&TabId=143

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86 Robert A. Brown and William F. Hunt. (2012). Improving bioretention/bio fi ltration performance with restorative maintenance. W ater Sci ence &Technology , 62(2).361 Unified Facilities Criteria. (2015, July). Low Impact Development. UFC 3 210 10. Retrieved f rom: https://www.wbdg.org/ccb/DOD/UFC/ufc_3_210_10.pdf V.G. Mitchell, A. Deletic, T.D. Fletcher, B.E. Hatt, & D.T. McCarthy . (2007). Achieving multiple benefits from stormwater harvesting. Water Science & Technology , 55(4), 135 144 Weizhon g Su. Gaobin Ye. Shimou Yao, & Guishan Yang.(2014, June). Urban Land Pattern Impacts on Fl oods in a New District of China , Sustainability . 6 ( 10), 6488 6508. Retrieved from: www.mdpi.com/journal/sustainability Wu Che , Yang Zhao , Zheng Yang , Junqi Li, & Man Shi. (2014 , July ). Integral stormwater management master plan and design in an ec ological community, Journal of environmental sciences, 26, 1818 1823 Wuhan Bureau of Commerce. (2010). Assessment of Wuhan Investment Environment for 2010. 5, 38. Retrieved from: http://www2.deloitte.com/content/dam/Deloitte/kr/Documents/china business center/2014/kr_cbc_investment_hubei wuhan_201402.pdf