Citation
Pilot program to quanitfy shoreline changes in Lee County

Material Information

Title:
Pilot program to quanitfy shoreline changes in Lee County
Series Title:
Pilot program to quanitfy shoreline changes in Lee County
Creator:
Kreuzkamp
Place of Publication:
Gainesville, Fla.
Publisher:
Coastal & Oceanographic Engineering Dept. of Civil & Coastal Engineering, University of Florida
Language:
English

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Source Institution:
University of Florida
Holding Location:
University of Florida
Rights Management:
All applicable rights reserved by the source institution and holding location.

Full Text
UFL/COEL-97/002

PILOT PROGRAM TO QUANTIFY SHORELINE CHANGES IN LEE COUNTY
ANNUAL REPORT
By
August J. Kreuzkamp and
Robert G. Dean

February 24, 1997
Project Sponsor:
Lee County Division of Environmental Services 1500 Monroe Street Fort Myers, Florida 33901




Table of Contents
Page
List of Figures ................................................................................ ii
List of T ables ................................................................................ iii
Executive Summary ........................................................................ iv
Introduction .................................................................................. 1
Previous W ork ................................................................................ 1
Aerial Photographs ........................................................................... 3
G round Truth ................................................................................. 4
Shoreline Location ........................................................................... 7
Methodology For Digitizing Photographs ................................................. 8
A nalysis of D ata ............................................................................... 11
R esults ........................................................................................ 16
Sources of Error ............................................................................... 23
Improvements ................................................................................. 24
Summary, Conclusions & Recommendations ............................................ 26
Literature Cited .............................................................................. 28
Appendix A: Ground Truth Profiles ..................................................... A- 1
Appendix B 1: Data Analysis of Aerial Survey taken on February 5, 1996 ......... Bl-1
Appendix B2: Data Analysis of Aerial Survey taken on August 25, 1996 ......... B2-1
Appendix C: Frequency Distribution Showing Results of Accuracy ................ C-1
Appendix D: Shoreline Change Results ................................................. D-1
Appendix E: Factors Limiting the Accuracy of Aerial Photography ................. E- 1
i




List of Figures

Figre Pg
1 Profile locations on Captiva Island..................................... 5
2 Sample profiles taken at R-088........................................ 6
3 Tidal prediction near Estero Island, Florida 2/04/96 2/06/96........... 7
4 Tidal prediction near Estero Island, Florida 8/25/96 .................... 8
5 AutoCAD display window showing a portion of the base map of
Captiva Island....................................................... 10
6 AutoCAD display window showing the composite map of Captiva
Island being assembled..............................................11
7 Comparison of uncorrected data sets................................. 16
8 Comparison of uncorrected data sets excluding problem areas .......... 18
9 Comparison of results determined by applying various computations
to all February data (including problem areas) ......................... 19
10 Comparison of results determined by applying various computations to all August data (including problem areas) .......................... 19
11 Comparison of shoreline changes for the entire county ................. 20
12 Comparison of shoreline changes for the entire county excluding nourished areas...................................................... 21
13 Comparison of shoreline changes at profiled locations excluding nourished areas ..................................................... 21
14 Comparison of shoreline changes at profiled nourished areas ........... 22




List of Tables
Table EM
1 Flight and equipment information ................................................ 3
2 Dates ground and aerial surveys were performed ............................. 5
3 Sample data set for Routine #1 .................................................. 13
4 Sample data set for Routine #2 .................................................. 14
5 Sample data set for Routine #3 .................................................. 15
6 Summary error results for each aerial survey by island ....................... 17
7 Potential errors due to camera tilt ............................................... 23




The outer coastline of Lee County, Florida consists of a series of barrier islands all of which experience episodic erosion due to storms and portions of which are subject to long term erosional trends. With such a dynamic and valuable shoreline, the county has participated in actions to maintain portions of the shoreline by nourishment. In the process of maintaining the coastline, monitoring the shoreline position would be quite expensive and time consuming by ground survey alone. In an attempt to devise an efficient and relatively inexpensive monitoring method, a technique was developed based on aerial photography. This technique incorporated digitizing current aerial photography and referencing State of Florida Coastal Construction Control Line photos to create a composite map providing a continuous shoreline for each aerial survey performed. From this composite map, the change in shoreline position was obtained with reference to the coordinates of each DNR monument located throughout the county. Ground truth surveys were performed as soon before and after the aerial photographs as possible and used later to adjust the data and evaluate the method.
Throughout the process of refining this method, several developments were made which were found to produce more reliable data. The best accuracy for this method was found to be approximately llt feet for specific areas. The improvements included specifying larger scale aerial photographs, setting visual targets over known coordinates and coordinating the aerial survey with high tide.. The method's highest precision was found when observing the composite error of shoreline change between two successive aerial surveys. The results for this six month period indicate that the average shoreline had accreted approximately 8.6 feet (:t2.5 feet) due primarily to nourishment projects that occurred in the interim of this project. After the nourished areas were excluded from the sampling, the average natural shoreline was found to have eroded approximately 7 feet (2.5 feet). In considering these results, it is necessary to note that the period over which these results were obtained (six months) reflects the effects of individual storms rather than an erosional trend.
The best applications for this method would be to evaluate overall annual shoreline changes, monitor the performance of beach nourishment projects and evaluate coastal damage due to large storms. The effectiveness of this program and the reliability of its results would require the improvements already developed to be continued and further progress be made to minin-dze the remaining distortion in the photographs which could not be avoided with the equipment that was used.
It is recommended that further developments for this erosion study be made to continue to improve its accuracy by reducing the distortion in aerial photographs. The most efficient way to evaluate the effectiveness of various techniques that reduce distortion would be to concentrate all efforts first on two selected islands. By applying and testing improved techniques to a portion of the county would allow efforts to be focused on improvement and evaluation of methodology and thus set the stage for application to the entire county

Executive Summary




shoreline. Specifically, the recommended areas of improvement are the development and testing of methodology to:
1. Remove distortion from the photographs which is primarily due to small values
of roll of the aircraft during the photographic mission.
2. Detect the waterline automatically through the tonal (color) change on the
aerial photographs.
In addition to the above, the improvements developed over the Phase I efforts would be continued including: larger scale photographs, targeting of monuments and tide-controlled photography. Ground truth surveys would also be included as a means of calibrating and verifying the aerial photography.




Pilot Program to Quantify Shoreline Changes in Lee County Annual Report
Introduction
The Department of Coastal & Oceanographic Engineering of the University of Florida, under contract with Lee County Division of Natural Resources Management, conducted this pilot program to evaluate aerial photography as a means of quantifying shoreline changes in Lee County. Lee County's shoreline consists of approximately 40 miles of dynamic coastline on the Gulf of Mexico and comprises eight barrier islands. Aerial photography can provide the broad coverage needed, having been established as an effective method for documenting shoreline position at various beach nourishment sites and beach erosion studies. Distortion in aerial photography is a limitation to the accuracy achievable. Through the years there has been considerable development in equipment to rectify aerial photography; however the cost is substantial. The goal of this project is to utilize aerial photography as a basis for obtaining shoreline positions using conventional methods, which are cost and time efficient, and to calibrate and evaluate the results using conventional ground truth surveys. This report includes the specifications used throughout the project, methodology developed, pictorial examples to clarify concepts, data recorded and an evaluation of the data with associated errors. All efforts were made to obtain the best results for the project using the available data and equipment. Based on the resulting errors and lessons learned, recommendations are presented for a second phase which should yield considerable improvements in accuracy. During this study, two modifications to the procedure which produced considerable improvements in accuracy were: (1) Larger scale aerial photographs and (2) Targeting DNR monuments so that they would be identifiable in the aerial photographs. Due to the areal extent of the project area and the amount of data collected, Captiva Island was chosen as the area of focus in the main body of this report to show meaningful examples with a reasonable amount of graphs and tables. The complete results are provided in the appendices of this report.
Previous Work
Aerial photography first originated in the mid-1800s using cameras mounted on balloons and kites. With the invention of the airplane in 1902 by the Wright Brothers, it was not until 1913 when the airplane was first used for aerial photography for mapping purposes. The use of aerial photography was expanded during World War 1 (1914-1918) when its application for reconnaissance was recognized and later during World War 11 (1939-1945) when reasonably good quality stereo vertical (aerial) photographs were developed. Since that time, a multitude of technological advancements in equipment and technique have been made to advance the accuracy of aerial photography. (Wolf, 1983)
While aerial photographs contain great quantities of information, they also include a variety of distortions, which leads to their inaccuracy if left uncorrected. The distortions include those caused by: changes in the camera's altitude, changes in tilt of the aircraft, radial scale variations and relief variations of the surface photographed. The use of




vertical photographs to determine shoreline change began in the late 1960's. (Moffitt, 1969) Researchers attempting to determine historic erosion rates found that vertical photographs dating as far back as the 1930's were a more reliable source for shoreline position when compared with shoreline maps created during the same era. These researchers developed different techniques to extract the shoreline position from vertical photographs with varying levels of success in terms of their accuracy.
Utilizing historical aerial photographs, Stafford (1971) developed a method to determine the historical coastal erosion along the Outer Banks of North Carolina. Shoreline positions were found by taking point measurements perpendicular to the shore from stable reference points. By focusing on beach widths located near the "principal line" (or flight line), the distortion due to a plane's tilt could be minimized. Stafford was also able to minimize the inherent change in scale between photographs caused by a camera's change in altitude by grouping beach widths taken from the same photographs and then, after determining the scale for each photograph, the beach widths were recorded. The final product became a data base of beach widths which were compared with beach widths taken from other surveys in the same area.
Based on the work of Stafford and Langfelder, Dolan et al (1978) documented continuous shoreline positions and then compared those with earlier shorelines to determine rates of erosion. Their method, called the orthogonal grid matrix system (OGMS), involved using a projecting light table to superimpose photo images to the exact scale of a base map and manually trace the shoreline onto a USGS "T-Sheef' (topographic map). Changing the scale of the projected images once again helped eliminate the distortion associated with the change in camera altitude. Once all of the shorelines were traced onto one common base map, beach widths were measured at 100 meter intervals. Presentation maps were then recreated from this data but could not reflect the same completeness as the original base map. Several critics, including Leatherman (1983), judged this method to have less merit than that of Stafford. Although a portion of distortion was eliminated by maintaining a constant scale throughout entire sets of photos with this method, nothing was done to attempt to eliminate the distortion due to plane tilt. The recorded accuracy of the OGMS method was 6.3 meters (21 feet).
An important piece of equipment used to further reduce the amount of error in vertical photographs is the zoom transfer scope. The zoom transfer scope (ZTS) is very efficient in eliminating scale differences between sequential photographs and has the ability to stretch or shrink images in one direction about the axis of tilt to help reduce a portion of the distortion caused by tilt of the camera. The reason why only a portion is corrected is due to the fact that the ZTS is a linear adjustment device while distortion due to tilt is nonlinear as shown in Figures D1 and D2 in the appendix. Since zoom transfer scopes can not make the necessary scale corrections needed to eliminate all tilt distortion, it is necessary to utilize one side of an image at a time and superimpose the corrected points of interest onto a base map. This process is considered to produce reasonable results but found to be a time-consuming and tedious process and should be reserved for smallersized projects. (Leatherman, 1983) Other equipment that provides considerable




improvements forward is the analytical stereoplotter which has a documented accuracy of 5 feet. (Fisher and Overton, 1994)
Aerial Photographs
This program included conducting two sets of aerial photographs of the outer coastline of Lee County on February 5, 1996 and August 25, 1996. The specifications of the equipment and information for the two flights can be found in Table 1.
Contractor Kucera South Kucera South
Plane Cessna 206 Cessna 206
Altitude Flown 3,000 feet 1,500 feet
Camera Equipment Ziess RMKA 15/23 Ziess RMKA 15/23
Filters Minus B, yellow filter Minus B, yellow filter
Film Type Kodak Type 2405 B/W Kodak Type 2405 B/W
Approximate Scale 1"=500' 1"=250'
Width of Negative 230.0 mm =9 inches 230.0 mm -9 inches
Time of Flight 10:54am 11:36am 9:49amn 10:36am
Table 1 Flight and equipment information
Under "Camera Equipment" in Table 1, the "15" signifies the focal length of the lens (actually 152.28 mm) and the "23" signifies the width of the negative (actually 230.0mm). The filter mentioned, the Minus B filter, was used for the photographs to reduce the amount of blue light through the lens. This light causes a haze to develop on the film reducing the contrast required to see detail. It is important to understand that the scale of the photographs is not exact or consistent throughout each set of photos. The greatest sources of these inconsistencies and inaccuracies are due to: changes in the camera's altitude, changes in tilt of the aircraft, radial scale variations and relief variations of the surface photographed. These factors are discussed in more detail in Appendix D of this report. Finally, in order to assist in relating sequential photographs, a 60% overlap in photographs was initially specified for both sets of photographs. It was later determined, that 60% overlap was considerably more than needed for digitization. By eliminating every other photo, the number of photos digitized was reduced by 50% while still maintaining a 20% overlap between the remaining photos.
The six month period between photographs was to provide the greatest amount of beach width contrast in a limited time frame. This variation in beach width is due to the recovery of the beach profile caused by the change in seasonal climate. In a six month period of time, a change in the cross-shore profile is caused by different types of wave activity between the winter and summer months. In the winter months, storm systems tend to be more intensive and frequent which create larger and more frequent wave activity compared to that in the summer.




Scheduling the time and day of aerial photography was initially considered to be inconsequential. Thus, no special instructions were provided to the sub-contractor for the first aerial survey as to the phase of the tidal cycle for the photography. It was originally believed that the High Water Line would be preserved for a longer period of time than was later determined to be the case. More details about the contributing factors which cause this problem will be discussed later in the Shoreline Location section. It is common practice that photos be taken near noon-time during the winter months to avoid unnecessary shadows and in the early morning during the summer to avoid the morning cloud cover. This cloud cover which obstructs the detail in the photos typically appears around mid-morning and continues throughout the rest of the day. Since the success of an aerial survey is also weather dependent, for the second set the subcontractor was provided with a tide table including high tides for the month and specified to start taking the photographs within a time frame of an hour (approximately) after the estimated time for high tide.
Ground Truth
Ground truth surveys were performed as soon as practical before and after the aerial photographs. The availability of two ground surveys for each set of photographs had two benefits. One benefit was by having two sets in a short time period, it would be possible to compare data between ground surveys. By doing so, irregularities due to human error in field measurements would be evident. The second benefit gave the ability to recognize storm altered topography immediately before or after the photography was scheduled. With ground truth data available both before and after the time of the aerial survey, it was possible to select the ground truth data which best represented the shoreline at the time the aerial survey was performed or to interpolate or average results from the two surveys.
Each ground survey consisted of a series of 46 profiles of the outer coastline of the county at approximate one mile intervals. A three or four person crew conducted the surveys with areas accessed by either boat or car depending on the particular island. The equipment used to measure the characteristics of the profiles at the selected monuments included that for standard ground surveys: level, level rod and tape. Each profile incorporated one of the 239 Department of Natural Resources monuments for reference which exist throughout the shoreline of Lee County. Each monument references a discrete elevation and location based on the National Geodetic Vertical Datum and state plane coordinate system. This information is provided in the Florida Department of Natural Resources Bureau of Beaches and Coastal Systems, Coastal Data Acquisition last revised 2/04/92 referred to as 'Monument Descriptions". Locations of the profiles taken on Captive Island are shown in Figure 1.




RED FISH P GULF OF MEXICO

P/NE ISLAND SOUND
CAP11VA ISLAND

R-099'

R-104'

0 5000 10,000 FT.

BLIND PASS-'
M1ERIAL TAINED FROM NOAA NAUTICAL CHART 11427 (OCT 1978) AND NOAA NAUllCAL CHART 11425 (MAY 190)
WIVRTY OF FLORIDA LEE COUNTY COASTULINE STUDY GROUND TRUTH
C0*TL & O@MO.P.I. C CAPTIVA ISLAND VATH PROFILE LOCATIONS
mmltu .lWlm.T

L
Figure 1 Profile locations on Captiva Island
Dates for the ground and aerial surveys are shown in Table 2. Survey #2 was chosen to represent the ground truth for aerial survey #1 due to its timing being much closer than Survey #1. Resulting beach widths for survey #'s 3 and 4 were averaged to approximate the most accurate beach width at the time aerial survey # 2 was performed. Certain exceptions had to be made in cases where the survey crew was denied access or previously chosen monuments were destroyed or altered by construction or erosion.

Survey #1 11/18/95 11/19/95 & 12/02/95 1
Aerial Survey #1 2/05/96
Survey #2 2/10/96 2/12/96
Survey #3 8/16/96 8/18/96
Aerial Survey #2 8/25/96
Survey #4 8/27/96 8/28/96

Table 2 Dates ground and aerial surveys were performed

NORTH




In order to minimize the number of profiles shown in Appendix A, any profiles not referenced for ground truth were not included on the drawings. Refer to Figure 2 for an example of how the profiles were documented. Notice in the figure that the vertical scale is exaggerated compared to the horizontal scale to emphasize the profile relief.
"-N"..... ,o,, -_~r. ...... ,,

1+00 2+00 3+00 4+00
0WMCE (FEE13
0 10 20 Fr.
%RCA SCAL i;
0 40 SOFT.
HOFUZONTL SCALE
LEGEND: NOTES:
. . -- SURNY l (12/02/95) 1. 5TA. 0400 DEPICTS THE LOCATION OF EACH MONUIENT
1. ElVAl1NS REE TO NAG.VD
- SURVEY 04 (8/27/90) & ACCES DENIED D DURING SURVEY 0i
Figure 2 Sample profiles taken at R-088
The beach width at each profile was established based on the profile surveys and a chosen water elevation. Based on McBeth (1964), the differences between the Mean High Water Datum and the High Water Datum were determined to be insignificant for mapping purposes. For this reason the Mean High Water Datum, MHWD was selected. The MHWD relies upon statistical data based on the average height of the High Water elevation over a nineteen year period. This datum, which changes slightly along a long shoreline, is documented in "Transformation of Historical Shorelines to Current NGVD Position For the Florida Lower Gulf Coast" by Balsillie, Carlen and Watters (June 1987). The range in elevation of the MHWD varies along the Lee County shoreline from +1.17 feet NGVD to +1.43 feet NGVD with the average value equal to +1.28 feet NGVD. With the elevation of the MHWD known at each monument throughout the county (based on Balsillie et al) and having the profile information from the surveys, the beach width could be determined by finding the horizontal distance between the location of each monument and its corresponding Mean High Water position on the profile.

11W
"O.00 '
F, 4.0 d 4 W (0 14
LOW0 0.

W
8
Z




The beach width from the February 5th and August 27th surveys were also included on the profiles as shown above and are presented for the entire set of profiles found in Appendix A. These beach width values would later be used to evaluate the amount of error in the composite map by comparing beach widths obtained from the composite map with the ground truth determined beach widths.
Shoreline Location
The shoreline is technically the boundary that exists between land and water. Its position is dependent on several factors including wave and current processes, sea level change, sediment supply, coastal geology and morphology, and human intervention. One of the most important and sensitive steps in the procedure was defining the shoreline position from the photographs. It is important to choose a discriminator or indicator which is welldefined as well as being selected consistent throughout the entire set of photographs. Regardless of the indicator, the measurements taken from the digitized image models can later be corrected using the ground truth to calibrate the results. The shoreline indicator commonly used by coastal photogrammetrists is the High Water Line which represents the highest extent of the most significant high tide over the past day which would also include wave run-up and setup. This line can be found at the place of tonal (color) change between wet and dry sand. Unfortunately there are two factors which make it very difficult to locate this region. One factor is the local semi-diurnal tide which creates only one significant high tide daily. The significant high tide before the first set of aerial photographs was taken occurred at 12:14am the night before at an elevation of 2.6 feet above the Mean Low Low Water Datum (MLLWD). The semidiurnal tide effect in the vicinity of Estero Island between February 4!h to the 5h is provided in Figure 3, taken from the program Xtide (Version 1.5beta).
Matanzas Pass, Estero Island. Florida
02-04 02-04 02-05 02-05 02-05 02-05 02-06
13:15 18:41 0:14 7:19 13:31 19:17 0:49
4 ft

Figure 3 Tidal prediction near Estero Island, Nior=da 2/U4190 -,




The longer the time between the significant high tide and the time of the photos, the more difficult it is to define the High Water Line through the tonal difference, of the wet and drying sand. The intensity of the Florida sun, the second factor, reduces the acceptable time window even further by drying the sand even faster. For these reasons the instantaneous "high water line" was taken as the shoreline location which includes the effects of: tidal elevation, local wave run up and wave setup at the time and place each photo was taken.
The timing of the second set of aerial photographs gave more consideration to the tide, sun intensity and daily cloud cover in order to have the high water line better preserved. The second set of aerial photographs was taken on August 25, 1996 between 9:49am and 10:36amn with the high water tide at 9:08am at a tidal elevation of 2.9 feet MLLWD. This information was also taken from Xtide 0 shown below in Figure 4.
Mlatanzas Pass, Estero Island, Florida
08-25 08-25 08-25
4:12 10:.01 17:421
4 ft
3
'I~laiii, 1,111i, I
. . . . ...... . . . . . . . . . . .. .. .. .. . .... . . . .
Figure 4 Tidal prediction near Estero Island, Florida 8/:25/96
For the second set of photographs, the base of the swash zone was found to be well defined throughout the set compared with the high water line which had areas that were lacking in contrast. Along with the fact that there was minimal wave activity evident on the photos for that time of day, choosing the instantaneous water line as the shoreline indicator seemed reasonable. Once the shoreline positions were recorded and compared, based on the shift of the shoreline, it would be possible to determine the amount of shoreline advancement or recession.
Methodology For Digitizing Photographs
Once the photographs were taken and the ground survey data were recorded and processed, the next step was to determine the best method to digitize the aerial photographs taking into account time required and best results. Equipment used throughout all different approaches included using a Cal Comp Digitizer tablet which was




connected to a 486 DX computer with AutoCad Release 12 software (a drafting program) as the user interface. The paragraphs below chronicle the development procedure for photograph digitization.
The first technique was to tape a series of corresponding photographs together in sets of five or so and then digitize each set of photographs. Much attention was paid to common objects on sequential photographs which aided in both the manual assembling of photographs into sets of five and later the assembling of those sets of five with other sets forming entire islands using AutoCad. It was desired to use common objects as control points, that had minimal relief variations (changes in elevation which cause distortion of the object). Parking lots, pools, tennis courts and roads were found to provide the best references. This worked well in developed areas however in undeveloped areas some difficult choices had to be made by selecting items like large debris on the beach or shadows near the beach of large structures. Digitizing each set of photographs involved a Computer Aided Drafting program (CAD) operator calibrating the digitizer tablet in order to preserve the scale of the photographs and then Arace" features on each set of five photographs. This created an image which only included these traced features. The sets of images were then joined together using the drawing program with every attempt made to obtain the best fit of all the control points included in the images. Once an entire island was assembled, visual targets that were set over DNR monuments were used to transform the islands' shorelines from an arbitrary coordinate system to the State plane coordinate system. After the photographs were digitized, any significant errors could be seen in the dimensions of the images created. It seemed likely that joining the photos together by hand into the sets was responsible for a substantial amount of the error.
The next technique included digitizing photographs individually and then assembling the digitized images together using the same CAD drawing program mentioned earlier. Control points on sequential photos were again used to guide in the assembly of the various islands. The benefit of this method was that the images could be laid over one another similar to using a light table. This enabled more control points to be seen and be used to help in the assembling process. Once assembled and moved into the State plane coordinate system, again using visual targets, it became apparent that there was still a considerable amount of error in the series of photographs most likely due to the inherent distortion in the photographs.
The final technique used enabled some of the distortion to be eliminated. It was concluded that the State of Florida Department of Natural Resources Coastal Construction Control Line (CCCL) aerial photographs for Lee County (taken on 10/14/88) were somewhat rectified since the amount of distortion appeared minimal and had state plane coordinates overlaying the photos. The first step was to chose control points found in all three reference sets (CCCL photos, Feb. '96 photos and Aug. '96 photos) having similar properties as those mentioned earlier. With close to 10 years between the CCCL photos and the recent sets of photos, the increase in developed areas made it somewhat challenging to determine the control points in these particular areas. After calibrating the digitizing tablet based on the state plane coordinates displayed, the selected control points in the CCCL photographs were then digitized creating a map of




control points with known state coordinates. A map of control points on Captiva Island can be seen in Figure 5 below.
430495 1401.807904.4901 PROFILES
ITY o, TENNIS E*' IS
(PIER
GULF BUt~t
MEXICO
TENNIS
COURTS
ROAD
TrENNIS COURTS
* ROAD
Figure 5 AutoCAD display window showing a portion of the base map of Captiva Island
Once the control points were determined, both sets of recent photographs were digitized including the depicted shoreline position, reference points and visible targets. To achieve greater accuracy, before the second set of aerial photographs was taken, supplementary visual targets were placed over 16 DNR monuments throughout the county. In order to minimize fieldwork, the monuments selected to be targeted were part of the group used in the profile surveys. Targeting the monuments was accomplished by the combined efforts of the University of Florida Coastal & Oceanographic Engineering Department and the Division of Natural Resources Management of Lee County. The individual digitized images of the 9" x 9" photos for both sets of recent photographs were next imported into the base map and placed in its best-fit location based on the control points mentioned above. Here, a CAD application best served our needs by having the ability to change the scale, change the alignment and shift images all with ease and minimal computer time. Each set of images was then placed on a drawing layer inside the CAD application. This was done to keep the two sets of recent photo images separated in order to reduce confusion in editing later on. Figure 6 shows image blocks (created by digitizing aerial photographs) being positioned in their best fit location over the base map utilizing the control points labeled. Once digitizing and assembling of composite maps (a complete sequential set of image blocks for an entire island) were completed, reference lines were




then started at the coordinates for every monument in the county (information provided in the "Monument Descriptions") and drawn perpendicular to the coastline, extending past the shorelines for both recent sets of images. The distances from the monument locations to the corresponding shorelines (HWL) were then recorded.
.* :...:. 430352.2862.807904.4901 PROFILES ..:-:

. 9 IN PHOTCOWAPHS(TYP.)

MEXICO
P OEL LOC.A1'ON4 G'YP.)

Figure 6 AutoCAD display window showing the composite map of Captiva Island being
assembled
After comparing the beach widths obtained with this method to the ground truth beach widths, some isolated areas were found to still have significant errors ranging from 40 to over 100 feet when compared with other nearby profiles. These particular locations were then re-digitized and imported again into the composite map utilizing additional reference points. In some cases, this provided a better fit and produced better results.
Analysis of Data
Once beach widths were obtained from the composite map, they were compared with the ground truth determined beach width values to judge the accuracy of the composite map. Other than distortion as a reason for discrepancies found, other reasons were also considered. The high water line represented in both sets of photographs is similar to a contour found on a topographic map with its elevation being the sum of the tidal elevation, storm surge, wave setup and wave run-up. One problem with this is the study focuses on the outer coastline of the county, which consists of barrier islands. The presence of inlets which cut through these barrier islands will always have an influence on




the elevation of the tides, resulting in varying tidal elevations throughout the county. Other factors that will seldom be the same throughout a lengthy shoreline are the intensity of the wind and the size of the waves that reach the shore due to local bathymetry and exposure. Both are important characteristics on which storm surge, wave setup and wave run-up are strongly dependent. This change in wave activity can be seen in both sets of aerial photographs taken for this study which would obviously cause discrepancies in the elevation of the HWL selected.
With the above discussion as background, there are several ways to attempt to account for these changing variables. Setting up the proper instrumentation along the entire county to measure tide, wind strength and wave characteristics at key locations simultaneously with the photography would be both expensive and time consuming. It was felt more advantageous and practical to adjust the high water line position data based on ground truth data. Three different routines of adjusting the data included:
1. Leave the error data unchanged for a control (refer to Table 3).
2. For each island, shift all mean high water positions so that the average
error for each island's data reduces to zero (refer to Table 4).
3. For each island, determine the required change in water level (due to
tide and run-up) needed to reduce the average error of the sample error data to zero (refer to Table 5). This differs from procedure 2,
above, due to the varying beach slope along the county shoreline.
The third routine was conceived after varying error results were examidned throughout the county. If the error was due in part to the water level being different than MHWD, the error would be reduced by applying a uniform difference in elevation for each island in combination with the beach face slopes of adjacent profiles.
Once the data sets were adjusted by the above methods, all three sets of data were then calibrated to minimidze remaining errors. Calibration includes finding errors associated with any two particular monuments and then linearly interpolating those amounts and applying as a correction factor to all those locations between the two. The errors found at monuments other than those selected for calibration, would then be used to help determine the accuracy accomplished by the two procedures.
The two methods of data calibration include:
1. Utilizing the first and last monuments on each island as the ground
truth profiles. (Calibration #1)
2. Utilizing every other monument on each island as ground truth
profiles. (Calibration #2)




LEE COUNTY COASTULINE STUDY
CAPTIVA ISLAND
February 1996 Survey Information Calibrated Utilizing Raw Data
Raw Data Calibration Utilizing Calibration Utilizing
DNR Ground High Water Line Error Without The First and Last Monument of the Island Every Other Monument of the Island
Monument Truth Position Without Correction Interpolation Calibration High Water Line Error Interpolation Calibration High Water Line Error
(Feet) Correction (Feet) Number Coefficient Position (Feet) (Feet) Number Coefficient Position (Feet) (Feet)
A-46-2 126.1 6.2 119.9 6.2 119.9
R-85 833.3 6.2 827.1 62 827.1
R-86 520.0 6.2 513.8 6.2 513.8
R-87 383.4 6.2 377.2 6.2 377.2
R-88 251.3 257.5 6.2 6.2 251.3 0.0 6.2 251.3 0.0
R-69 453.9 1 4.9 449.0 1 6.6 447.3
R-90 215.1 2 3.8 211.5 2 6.9 208.2
R-91 157.5 3 2.3 155.2 3 7.3 150.2
R-92 192.2 4 1.0 191.2 4 7.7 184.5
R-93 224.8 5 -0.3 225.1 5 8.1 216.7
R-94 148.3 153.3 6.0 6 -1.6 154.9 6.6 6 IA 144.9 -3.4
R-95 148.3 7 -2.9 151.2 7 8.8 139.5
R-96 117.7 8 -4.2 121.9 8 9.2 108.5
R-97 108.7 9 -5.5 114.2 9 9.6 99.1
R-98 130.1 10 -6.8 136.9 10 0.9 120.2
R-99 221.8 232.1 10.3 11 -8.1 240.2 18.4 11 10.3 221.8 0.0
R-100 194.0 12 -9.4 203.4 1 7.0 187.0
R-101 277.0 13 -10.7 287.7 2 3.6 273.4
R-102 219.0 14 -12.0 231.0 3 0.3 218.7
R-103 275.0 15 -13.3 288.3 4 -3.1 278.1
R-104 256A 268.1 11.7 16 -14.6 282.7 26.3 S -6.4 274.5 18.1
R-105 156.8 17 -15.9 172.7 6 -9.8 166.6
R-106 4253 18 -172 442.5 7 -13.1 438.4
R-107 429.4 19 -18.5 447.9 8 -16.5 445.9
R-108 176.9 157.1 -19.8 20 -19.8 176.9 0.0 9 -19.8 178.9 0.0
R-109 374.2 -19-8 394.0 -19.8 394.0
Average Error: 2.7 Avg. 17.1 Avg. 7.3
Standard Deviation: 12.9 S.D. 9.9 S.D. 15.2
Note: The monuments at which ground truth profiles are located are shown in bold type.

Table 3 (Sample data set for Routine #1)




LEE COUNTY COASTLINE STUDY
CAPTIVA ISLAND
February 1996 Survey Information Calibrated Utilizing Average Error Correction
Raw Data Error Correction Calibration Utilizing Calibration Utilizing
DNR Ground High WaterLine Error Without HighWater Line Error With Avg. The First and Last Monument of the Island Ever Other Monument of the Island
Monument Truth Position Without Correction Position With Error Correction Interpolation Calibration High Water Line Error Interpolation Calibration HighWater Line Error
(Feet) Correction (Feet) Avy Error Correction (Feet) Number Coefficient Position (Feet) (Feet) Number Coefficient Position (Feet) (Feet)
A-46-2 126.1 123.4 3.5 119.9 3.5 119.9
R-B5 833.3 830.6 3.5 827.1 3.5 827.1
R-86 520.0 517.3 3.5 513.8 3.5 513.8
R-87 383.4 380.7 3.5 377.2 3.5 377.2
R-88 251.3 2575 6.2 254.8 3.5 3.5 251.3 0.0 3.5 251.3 0.0
R-89 453.9 451.2 1 2.2 449.0 1 3.9 447.3
Ra-g90 215.1 212.4 2 0.9 211.5 2 4.3 208.2
R-91 157.5 154.8 3 -04 1552 3 4.6 150.2
R-92 192.2 189.5 4 -1.7 191.2 4 5.0 184.5
R-93 224.8 222.1 5 -3.0 225.1 5 5.4 216.7
R44 148.3 183.3 5.0 150.6 2.3 a 4.3 154.9 6.6 8 5.8 144.9 -3A4
R-95 148.3 145.8 7 -5.6 1512 7 6.1 139.5
R-96 117.7 115.0 8 -6.9 121.9 8 8.5 108.5
R-97 108.7 108.0 9 -8.2 114.2 9 8.9 99.1
R-98 130.1 127.4 10 -9.5 136.9 10 7.2 120.2
R-49 221. 232.1 10.3 229A 7.6 11 -10.8 2402 18A 11 7.6 221.8 0.0
1R-100 194.0 191.3 12 -12.1 203.4 1 4.3 187.0
R-101 277.0 274.3 13 -13.4 287.7 2 0.9 273.4
R-102 219.0 216.3 14 -14.7 231.0 3 -2.4 218.7
R-103 275.0 272.3 15 -18.0 288.3 4 -5.8 278.1
R-104 256A 268.1 11.7 285.4 6.0 16 -17.3 282.7 20.3 6 4-0.1 274.5 18.1
R-105 158.8 154.1 17 -18.6 172.7 6 -12.4 166.6
R-106 425.3 422.8 18 -19.9 442.5 7 -15.8 438.4
R-107 429.4 428.7 19 -21.2 447.9 8 -19.1 445.9
1R-108 176.9 157.1 -16.8 154A -22.5 20 -22.5 176.9 0.0 9 -22.5 176.9 0.0
R-109 374.2 371.5 -22.5 394.0 -22.5 394.0
Average Error 2.7 Avg. 0.0 Avg. 17.1 Avg. 7.3
Standard Deviation: 12.9 S.D. 12.9 S.D. 9.9 S.D. 15.2
Note: The monuments at which ground truth profiles are located are shown In bold type.

Table 4 (Sample data set for Routine #2)




"t- 4 :q q 4Ra q
S 1 a
V E 21
iiR ~ ~ ~ t~ Wh 1 wcihw W A Mi Ridil 4iiR q i 55 Sty Iw I
O
SI/
oo h
IC _1_. _____.........____.____.__.______0
*0
u s 4L z I
F2
CCL
Joo
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iii ii i i,-5 R50 0 ill== c. ..
U
zR /'S
15




Results

All of the data analyzed are presented in Appendix B in tables similar to those shown in Tables 3 through 5 for Captiva Island. The data on those spreadsheets were then condensed and used to evaluate various facets of the project. For each comparison, a relative frequency distribution of error was calculated and shown in the form of histograms. Each histogram highlights the merits of one procedure over another by comparing results obtained from a specific process. All of the histograms utilized to make any conclusions are shown in Appendix D with a summary presented and discussed below. Included on each histogram are the standard deviation and mean for each data set. These statistical tools were chosen in order to provide numerical descriptions for the degree of spreading and average of each data set. The standard deviation of a data set indicates to what degree the data fluctuates from the mean, with larger deviations corresponding to a greater spread of the data.
Lee County Raw Survey Data
05-Feb-96
(Mean=3.6 ft,SD=22.2 ft)
E25Aug-96
S...... ...2.-Aug-96(Mean=3.3 ft,SD=R 1.8 ft)
.... ~ ~ ~ .. .......,_ o
Error between Aerial Photographs and Ground Truth (Feet)
Figure 7 Comparison of uncorrected data sets
The histogram in Figure 7 shows the relative frequency distribution of error calculated for the entire county for the first and second aerial surveys. Based on the information shown, the mean errors for both surveys are quite similar while the standard deviation of the data for the February survey is much greater than the standard deviation of the data for the August survey. It was anticipated that the mean values would represent the amount the representative shoreline was needed to be shifted to conform closer to the High Water Line. Refinements in the latter aerial survey appear to be the reason for the improvement reflected by the smaller standard deviation for the August aerial survey. These refinements will be discussed later under Improvements.




A summary table of the data in Appendix B, is provided in Table 6 to show the errors associated with each island independently. By noticing the standard deviations for each island in Table 6, the larger contributors of error are: Lacosta Island, Estero Island and Lover's Key. Lacosta Island and Lover's Key are less developed islands which results in less available control points (Le. roads, pools, tennis courts, etc.) when compared with other more developed islands (ije. Sanibel Island or Captiva Island). With less control points, it becomes much more difficult to create an accurate composite map. Adding visual targets to these areas will help remedy the problem. Uncertainty with the reliability of the composite map of Estero Island is due to a discrepancy found while digitizing the CCCL photos. After several attempts of digitizing the CCCL photos, the main road near monument R-203 was consistently disjointed by 20+ feet on the created base map. It is therefore possible that there may be an error in the CCCL photos used and that portion of the base map for Estero Island should be corrected by referencing a set of CCCL photos taken at another time or by other means.
. ... .... .~~~~~A.... ..o ..A g.ErrSD
Gasparilla Island -5.7 9.8 12.4 7.4
Lacosta Island -9.0 31.9 -2.8 19.9
North Captiva Island -1.3 7.4 4.4 11.4
Captiva Island 2.7 12.9 7.1 7.3
Sanibel Island 10.8 18.5 3.3 7.5
Estero Island 20.0 29.1 -2.6 14.1
Lover's Key/Bonita Beach 1.0 29.3 1.9 13.2
Table 6 Summary error results for each aerial survey by island
In an attempt to focus on the accuracy of the method developed, these "problem areas" were excluded from the data with results shown in Figure 8. Removing the problem areas from the group sample reduced the error standard deviation and simultaneously increased the mean error. The change in standard deviation appears to show that areas which lacked control points or inaccurate control points resulted in an increased standard deviation. The shoreline positions obtained from these problem areas appears to have also had an influence on the average shoreline position with respect to the HWL however, the difference between the two mean values is still relatively small. Any value determined would have to be taken into consideration later when determining the total shoreline change for the entire county.




Lee County Raw Survey Data Excluding Problem Areas

0 1t 0 0R W8 2 !
Error between Aerial Photographs and Ground Truth (Feet)
Figure 8 Comparison of uncorrected data sets excluding problem areas
The next question was if any of the correction routines performed on the data resulted in significant improvements. Figures 9 and 10 focus on the various routines applied to each complete set of data. For both surveys, the scatter and average error of the data were reduced by a similar amount by either shifting the data or correcting for tidal change. Although the results for either method were not dramatic, it is still felt that these techniques (especially shifting the data) have merit by accounting for the discrepancies that would be found should the shoreline be incorrectly identified in the photographs of an aerial survey. After applying the two correction routines, each set of processed data was calibrated two different ways as discussed earlier. Resulting errors indicated that both methods of calibration consistently increased the error standard deviations.

0
C U.
0
0




Lee County Survey Data (February 5, 1996)

U0
0
8
6

0 In o U) O~ O n W 0 W 0 W 8 WQ8 0
Error between Aerial Photographs and Ground Truth (Feet)

Figure 9 Comparison of results determined by applying various computations to the
February data (Including problem areas)

Lee County Survey Data (August 25, 1996)

0
(0 (5I
*0 Lo
C
=
*

W In 0Wn onrnTu(Fe
Error betwen Aerli Photographs and Ground Truth (Feet)

Figure 10 Comparison of results determined by applying various computations to the August data (Including problem areas)
In order to examine the reliability of using aerial photography in determining shoreline change, frequency distributions representing the change in beach widths between February and August obtained from the composite maps were compared to the same obtained from ground truth profiles. Figure 11 shows the changes that occurred for the entire county over the six month time span. The discrepancies between the two methods are due to the




Relative Frequency Distribution of Adiusted Seasonal Shoreline Changes Throughout the Entire County
0.30.......................................... ................
0 .3 0. .. .. ... .. .. ... .. ..
.. .Aerial Photos
0.25 Avg.=8.6 ft; S.D.--489 ft
..... Ground Truth
0.20 Avg.=22.7 ft; S.D.=48.9 ft
0.15 .
I
0.10 .
0.05
0.00
V A
Shoreline Change (Feet)
Figure 11 Comparison of shoreline changes for the entire county
amount of sampling by each method. Results based on aerial photography documented shoreline change at every DNR monument (approximately 239 points spaced at 1/5 mile intervals) while the ground truth profiles determined the shoreline change at 40 points spaced at approximately 1 mile intervals. The positive mean values in Figure 11 for both methods are due to the nourishment projects that occurred between the two aerial surveys. In an attempt to investigate the natural shoreline processes for the region, Figure 12 excluded the nourished areas from the calculations. These areas included the southern tip of Gasparilla Island, Captiva Island, parts of Sanibel Island, Ft. Meyers Beach and Bonita Beach. By eliminating these nourished regions in the county, the histogram clearly shows that the remaining unnourished areas experienced a net shoreline recession even during the time between the winter and summer when shoreline advancement is expected. In order to better evaluate the validity of the results of Figures 11 and 12, Figure 13 shows the shoreline change determined from aerial photography at only profiled monument locations and then compared with the-change in shoreline position determined from the ground truth at the same locations. The higher value of the standard deviation for the aerial data was to be expected however the mean values only deviated from one another by approximately
2 feet which indicates the range of precision the method obtains.




Relative Frequency Distribution of Adjusted Seasonal Shoreline Changes Throughout the County Excluding Nourishment Sites

0.40
0.35 .
0.30
0
S 0.25 ...............
0.20
*
S0.15 -..
= o ................ ................n .. .. .. ... .... ... ...
0.10
0.05
v Shoreline Change (Feet)

Figure 12

IMAerial Photos Avg.=-7.0 ft; S.D.=27.9 ft

A

Comparison of shoreline changes for the entire county excluding nourished areas

Relative Frequency Distribution of Adjusted Seasonal Shoreline
Changes at Profile Locations Excluding Nourishment Sites
0.40 ...........
0 Aerial Rotos
0.35- Avg.0.2 ft; SD.=28.5 ft
a Ground Truth
0.3 ...... Avg.=2.5 f t; S.D.=15.8 ft
S0.25 I
S 0.20 .......
*
S0.15
0
I 0.10
0.05
o ooo oo oo ooo oo oo
- +
v Shoreline Change (Feet) A
Figure 13 Comparison of shoreline changes at profiled locations excluding nourished
areas




The last significant finding was the success in tracking nourishment projects as shown in Figure 11. After removing all other areas, Figure 14 indicates the impact those projects had on their respective beaches and the level of accuracy of the data obtained from aerial photographs for this application. With beach widths being expanded by more than one hundred feet in a limited time span, results from the composite map reflect changes of the same order determined from ground truth profiles. When considering the difference in values between the two methods, the difference in mean values calculated for those areas are relatively small Not only was this method able to document the displaced shoreline at the various nourishment sites, but also the displaced shoreline for areas nearby the construction caused by the natural spreading of the material. Combining the results from a composite map with strategically placed ground truth profiles would create a rapid and complete way of tracking the volumes of material placed at nourished locations.

Relative Frequency Distribution of Adusted Seasonal
Shoreline Changes at Nourished Profile Locations
0.60
E3AriaPotos
0.50- Avg.=103.1 ft
0 rudTruth
040Avg.==100. Oft
0.4
LL 0.30,0.200.10
0.00 A
CD CD 0 C0 0 0D 0D 0 0) 0 0
o O to C J CMJ CT 0o O
V Shoreline Change (Feet)A
Figure 14 Comparison of shoreline changes at profiled nourished areas




I ---------- --- -1
W
1 degree 26 ft 13 ft
3 degrees 80 ft 40 ft
Table 7 Potential errors due to camera tilt

Sources of Error

There are several sources of error in the shoreline positions determined by the photographic procedure including: misinterpreting the high water line, inaccurately digitizing the photographs, water level changes causing discrepancies in shoreline position and human error throughout any part of the procedure.
The effectiveness of this entire process is dependent on the person(s) determining and digitizing the shoreline position. The method is fairly labor intensive and requires attention to detail. Each step of the methodology requires total consistency throughout each set of photographs which contributes to the Mculty. A trained draftsperson would be the best candidate for this type of work. Error created by inaccurately determining the shoreline position from photographs is presently unavoidable and would increase should a smaller scale be used. For clarification, small-scale maps tend to show larger portions of the earth's surface while large-scale maps approach the actual size of the entity being mapped. Limitations of the digitizer tablet add to this error as well. The Calcomp digitizer tablet used to create the image models for this project has limitations in accuracy of 0.005 inches. At the smaller scale of 1"=500 feet, this accuracy could lead to an error of 2.5 feet.
Aerial photographs will always have an inherent error due to distortion which has to either be removed or circumvented, as this project attempted to accomplish. The sources of error that cause variations in scale and distortion include: changes in the camera's altitude, changes in tilt of the aircraft, radial scale variations and relief variations of the surface photographed. Appendix E explains each of these factors in greater detail. The largest of these sources of error for this project was felt to be the distortion due to camera tilt. This "tilt" is usually due to aircraft roll. Approximately one half of aerial photographs taken for mapping purposes are tilted between 1 to 3 degrees. (Anders and Byrnes 1991) Even a slight one degree tilt can cause non-linear scale variations throughout a photo which are Oficult to correct without the proper equipment/technology. The amount of error specific to this project that could be expected due to camera tilt is shown below in Table
8. Further explanation of how this error was determined is provided in Appendix E.




Improvements

Significant changes were implemented between the first and second sets of aerial photographs which are believed to have improved the accuracy of locating the shoreline position. It is strongly recommended that these improvements be included in subsequent aerial surveys as discussed in the following paragraphs.
Increasing the scale of the aerial photos seemed to have a significant influence on the results of accuracy determined. In this particular project, the first set of photographs was taken at a scale of 1"=500'. This scale made it difficult for the CAD operator, who digitized the photographs, to see detail including control points, shoreline indicators and visual targets. The second set of photographs had a larger scale of 1"=250' which helped improve detail in the photographs and reduce distortion. Displacements of objects due to camera tilt is inversely proportional to the scale of a photograph. Theoretically, by increasing the scale of the photographs by a factor of two will reduce the displacement of the distorted object by one half. Further explanation is given in Appendix D including Table D-1. It is believed that the larger scale is at least partially responsible for the improvement in results shown in Figure 7. Only additional photographic surveys will confirm this hypothesis.
Increasing the number of visual targets set over the DNR monuments located throughout the county helped in several ways. Visual targets were felt to be more reliable compared to other objects that were selected as primary control points since their state plane coordinates were already known compared to the coordinates of a tennis court that were identified in the CCCL photos. These visual targets also aided in the importing of images into the composite map, especially in areas where there were a limited number of common features found in the CCCL photos and the aerial photographs recently taken. These undeveloped areas include Lacosta Island, Lovers Key and parts of Sanibel and North Captiva Islands. It is important that for any subsequent aerial photographs, efforts should be made to have just as many, but preferably more, visual targets than were set for the August 25th run.
Coordinating the time of the aerial survey with the forecast time of high tide for the region was believed to help photographically document a much more concise location of the High Water Line. By providing the aerial photographer with a tide table for a onemonth time frame, the photographer was able to conform to the time frame specified while maintaining his constraints for time of day to photograph and requiring clear skies.
Possible alternative-irnprovements:
It is believed that any of the following techniques would improve the accuracy for determining the shoreline position. It is recommended that any changes in methodology be first applied to and evaluated for one or two small areas to determine its potential before implementing for the entire 40 miles of coastline. This should allow various




techniques to be developed and evaluated more effectively, thereby resulting in an optimal final procedure prior to application over a broad geographical area.
The best way to improve the project's results would be to eliminate the distortion in aerial photography caused by camera tilt. The approach would be to apply a space resection program to a scanned image of a photograph. Such a program has the ability to reduce the distortion in digitized images utilizing control points with known coordinates to obtain its best-fit position. The best fit is obtained by applying various algorithms including a least squares adjustment which conforms the location of the digitized control points to their proper scale and non-tilted position by means of a correction factor. The correction factor can then be applied to other objects, such as the scanned shoreline on the corrected image. Once the image is corrected, a computer would be used to interpret the shoreline position. Computers have the ability to decipher 256 shades of gray compared to 8-10 for the human eye. With the help of a computer operator, a computer could find consistencies and gradients in the intensity of light which would help identify the wet/dry line in the sand (high water line).
As an alternative to the above, a less complicated but possibly more costly procedure to produce improved results would be to obtain orthophotos from the aerial photographer. Orthophotos are corrected aerial photographs which have the scale variations due to plane tilt and change in altitude removed by using large stereoscopic plotters. This equipment is able to place the original photo back in its original tilted position and then project the image downward at its proper scale. Information taken from these rectified photos can then be treated as if taken from a map. Once the photos are corrected, they can be digitized as was done in Phase I or scanned and having the computer interpret the shoreline position as discussed in the preceding paragraph.




Since initiation of the project, many different techniques have been employed to create the most accurate composite map in order to extract the most precise shoreline measurements. The most significant improvements in accuracy were found between the two aerial surveys taken February '96 and August '96. Preliminary planning for the August survey specified a lower flight altitude (which produces a larger scale), an increase in the number of visual targets and flight time coordinated with the predicted high tide; all of which are believed to have contributed to improving the results. The best accuracy for the method developed in determining shoreline position was 1 1. 1 feet which is applicable for only the adjusted August survey data after the average error for each island's data was reduced to zero. The method developed by Dolan et al (1980) determined an error of 20.7 feet on a more energetic shoreline while Fisher and Overton (1994) documented that the accuracy of digitizing directly from aerial photographs and using USGS Topographic maps for control will have an error of 50 feet. When evaluating average shoreline change, the accuracy of the composite error improved to +9.5 feet based on the collective data. Stafford and Langfelder (1971) found similar results with a large magnitude of error in some instances while the mean of the composite differences was very small. It was concluded by Stafford and Langfelder that, "...the composite error was concluded to be sufficiently small so as to not have a detrimental effect on the study results expressed by mean beach location changes as long as adequate care was taken in the measurement process and provided that the most accurate type of aerial photograph available in a particular area was used."
After evaluating all of the data some interesting and useful information was determined. It appears that the average natural shoreline receded approximately 7 feet (2.5 feet) during the six month time frame. When including the nourished areas, the average shoreline accreted approximately 8.6 feet (2.5 feet). This shows that the nourishment projects appear to be helping control the amount of beach recession throughout the county. It is also important to realize that these numbers are influenced by the seasonal profile changes and storms that typically occur as mentioned earlier. The best way to filter out this uncontrollable factor is to use aerial photographs spaced at one or several year intervals when creating a composite map with special care that each aerial survey is performed during the same time of season.
To further improve the degree of accuracy, it has been recommended by researchers such as Anders and Byrnes (1991) among others that the error within erosion rate studies can be minimized by extending the time between surveys. If a shoreline change trend exists, increasing the temporal spacing results in shoreline changes which will eventually be larger than the inherent errors of the method used. Thus, the temporal spacing allows the error to be distributed throughout the associated time frame. For example, a 5 foot error determined for a 5 year erosion study would result in one foot of error per year.
This method developed here would also be suitable for documenting larger shoreline changes which occur over a shorter time span such as the result of beach nourishment projects and the impacts of major storms. For example, the average shoreline change

Summary Conclusions & Recommendations




including all of the nourished areas throughout the county was approximately 103 feet determined with aerial photography while ground truth determined the change to be 100.0 feet. Nourished areas not only experience rapid changes when placing sand within the design template during construction but when the material begins to disperse alongshore due to spreading and cross-shore due to profile equilibration.
A second phase to this study is recommended to further develop and automate the process. It is recommended that the second phase concentrate on: (1) rectifying the aerial photographs to remove distortions due to roll of the aircraft, and (2) automate digitization of the indicator representing the Mean High Water shoreline. The use of ground truth surveys would be continued as a means of evaluating the accuracy of the methodology implemented. Finally, it is suggested that the second phase effort would be most effective if focused on two areas, one developed and one in a more natural condition. This focus on two areas of reasonable longshore extent would allow methods to be developed and evaluated more rapidly and effectively and efforts to be concentrated on development of a procedure for application in future years.




Literature Cited

Anders, F.J. and M.R. Byrnes, "Accuracy of Shoreline Change Rates as Determined from Maps and Aerial Photographs." Shore and Beach, Vol. 57, p. 17-26, 1991.
Balsillie, J.H., J.G. Carlen and T.M. Watters, "Transformation of Historical Shorelines to Current NGVD Position For the Florida Lower Gulf Coast." 1987
Crowell, M. and S.P. Leatherman, M.K. Buckley, "Historical Shoreline Change: Error Analysis and Mapping Accuracy." Journal of Coastal Research, Vol. 7, p. 839-852, 1991.
Dolan, R., B.P. Hayden and J. Heywood, "New photogrammetric method for determining shoreline erosion." Journal of Coastal Engineering, Vol. 2, p. 21-39, 1978.
Dolan, R., B.P. Hayden, P. May, and S. May, "The reliability of shoreline change measurements from aerial photographs." Shore and Beach, Vol. 48, p. 22-29, 1980.
Fisher, J.S. and M.F. Overton, "Interpretation of Shoreline Position from Aerial Photographs." 24th International Conference on Coastal Engineering, Vol. 2, p. 1998-2003, 1994.
Leatherman, S.P., "Shoreline mapping: a comparison of techniques." Shore and Beach, Vol. 51, p. 28-33, 1983.
McBeth, F.H., "A method of shoreline delineation." Photogrammetric Engineering, Vol. 22, p. 400-405, 1956.
Moffitt, F.H., "History of Shore Growth from Aerial Photographs." Shore and Beach, Vol. 4, p. 23-27, 1969.
Stafford, D.B., J. Langfelder, "Air Photo Survey of Coastal Erosion." Photogrammetric Engineering, Vol. 37, p. 565-575, 1971.
Wolf, P.R., Elements of Photogrammetry, 2nd Edition, McGraw-Hill, New York, 628 p, 1983.




Appgndix A
Ground Truth Profiles




0
90
S
r'
90
Ii
SO
n M >
O Z
3
1
I
m
Co
0
n
-a

C
z
:R
m
0
Un
on
o
0
Fn Cu1
0
c
0
0
C
p
z
(1
G)
0
0
z
0

DISTANCE (FEET)

VERTICAL SCALE 1"=10'-0" HORIZONTAL SCALE 1"=40'-0"

LEGEND:
------- SURVEY f2 (02/10/96)
SURVEY #4 (08/27/96)

S10 20 FT.
0 40 80 FT.

NOTES:
1. STA. 0+00 DEPICTS THE LOCATION OF EACH MONUMENT
2. ELEVATIONS REFER TO N.G.V.D.

I
C

189.7' 178.3'

0+00 1+00 2+00

3+00

- ~




140.7' 135.4'

S800' "____ ____ ____- "-__-__-8.00' I,
0 .00'
4.00' --.- MEAN HIG-I WATEI (EL 41.17')
2.00' 0.00'
-2.00' "- ...
0+00 1+00 2+00 3+00
DISTANCE (FEET)
0 10 20 FT.
VERTICAL SCALE 1"=10'-0"
0 40 80 FT.
HORIZONTAL SCALE 1"=40'-0"
LEGEND: NOTES:
1. STA. 0+00 DEPICTS THE LOCATION OF EACH MONUMENT
- ----- -SURVEY #2 (02/10/96) 2. ELEVATIONS REFER TO N.G.V.D.
SURVEY #4 (08/27/96)

- U




-U
C

a ,o
oIl
I
0
.-u
0
IF e f go
0
M a
zo
Os
0
n
1n

z
m
0 on
0
m
a
0
0
z
0
c
z
0
< us <0

VERTICAL SCALE 1"=10'-0" HORIZONTAL SCALE 1"=40'-0"

LEGEND:
- - - - SURVEY #2 (02/10/96)
--- -- SURVEY #4 (08/27/96)

S10 20 FT.
0 40 80 FT.

NOTES:
1. STA. 0+00 DEPICTS THE LOCATION OF EACH MONUMENT
2. ELEVATIONS REFER TO N.G.V.D.

- A I

0+00 1+00 2+00

DISTANCE (FEET)

3+00




0 m0
2.
It >p 00
0 M
- 1,
I
o V Z .40
0
F cn
1.4

I I I 1 1

12.00' 10.00' 8.00' 6.00'
4.00' 2.00' 0.00'
-2.00'1
0+

1+00

2+00

3+00

DISTANCE (FEET)

VERTICAL SCALE 1"=10'-0" HORIZONTAL SCALE 1"=40'-0"

0 10 20 FT.
S40 80 FT.

LEGEND:
- - - - SURVEY #2 (02/10/96)
--- -- SURVEY #4 (08/27/96)

NOTES:
1. STA. 0+00 DEPICTS THE LOCATION OF EACH MONUMENT
2. ELEVATIONS REFER TO N.G.V.D.

- ~.

I

___,'_*.**.__ MEIAN HIGH WATEF (EL + 1.18')- - -- -

- 257.2' .
: - -253.9'

00

II




mm

X 0 Do
30 00

155.5'
146.6'

DISTANCE (FEET)

VERTICAL SCALE 1"=10'-0" HORIZONTAL SCALE 1"=40'-0"

3 10 20 FT.
3 40 80 FT.

LEGEND:
------- SURVEY #2 (02/10/96)
--- -- SURVEY #4 (08/27/96)

NOTES:
1. STA. 0+00 DEPICTS THE LOCATION OF EACH MONUMENT
2. ELEVATIONS REFER TO N.G.V.D.

3+00

- & a




t 308.8' A225.7'

- -.'_ _E AHG H W A R ( E L + 1 .1 8 ')
- -* 1 11 1 _.- _,

2+00

3+00

4+00

DISTANCE (FEET)

VERTICAL SCALE 1"=10'-0" HORIZONTAL SCALE 1"=40'-0"

0 10 20 FT.
0 40 80 FT.

LEGEND: NOTES:
- -- SURVEY l#1 (12/03/95) 1. STA. 0+00 DEPICTS THE LOCATION OF EACH MONUMENT
2. ELEVATIONS REFER TO N.G.V.D.
3. SURVEY #2 DATA NOT COLLECTED
--- -- SURVEY #4 (08/27/96)

-p

14.00' 12.00' 10.00' 8.00' 6.00'
4.00' 2.00' 0.00'
-2.00'

1+00




0
aO Elm,
Vo
MO
0
-z

C
z
m
O
0
on
U)
0
m
a
0
0
c
z
m
0
0
0
0
z
0

DISTANCE (FEET)

VERTICAL SCALE 1"=10'-0" HORIZONTAL SCALE 1"=40'-0"

LEGEND:
------- SURVEY f#2 (02/10/96)
--- -- SURVEY #4 (08/27/96)

3 10 20 FT.
3 40 80 FT.

NOTES:
1. STA. 0+00 DEPICTS THE LOCATION OF EACH MONUMENT
2. ELEVATIONS REFER TO N.G.V.D.

- i a

U

181.1' 178.2'

0+00 1+00 2+00

3+00




DISTANCE (FEET)

VERTICAL SCALE 1"=10'-0" HORIZONTAL SCALE 1"=40'-0"

3 10 20 FT.
3 40 80 FT.

LEGEND:
- - - - SURVEY #2 (02/10/96)
--- -- SURVEY #4 (08/27/96)

NOTES:
1. STA. 0+00 DEPICTS THE LOCATION OF EACH MONUMENT
2. ELEVATIONS REFER TO N.G.V.D.

0 zI1" ".
0
z
La rZ
-II

469.0'

6+00

- A I




C
z
m
0
rm
0
m
0
0
z
0
0
z
0
;I
e
5~

1 z.UU 10.00' 8.00' 6.00'
4.00' 2.00'
0.00'
-2.00"
4+

- a-- ----** --* -_'_- ._ M AN HIG-I WATEF (EL 41.20')
--.* -_-_- ....-

00 5+00

6+00

DISTANCE (FEET)

VERTICAL SCALE 1"=10'-0" HORIZONTAL SCALE 1"=40'-0"

LEGEND:
---------- SURVEY #2 (02/10/96)
SURVEY #4 (08/27/96)

0 10 20 FT.
0 40 80 FT.

NOTES:
1. STA. 0+00 DEPICTS THE LOCATION OF EACH MONUMENT
2. ELEVATIONS REFER TO N.G.V.D.

- b a

-562.2'
558.6'
-'K ---------------------------------

7+00




-U

a
m 0 z 1
M 0 Vo g 0 1 a zo
-I
X
-o
0
in

C
z
Z
m
m
0
n
0
5
0
C
0
z
P1 Un
0
;a
0
c
z
0
Z

1+00

2+00

DISTANCE (FEET)

VERTICAL SCALE 1"=10'-0" HORIZONTAL SCALE 1"=40'-0"

LEGEND:

------- SURVEY f2 (02/10/96)
--- -- SURVEY #4 (08/27/96)

0 10 20 FT.
0 40 80 FT.

NOTES:
1. STA. 0+00 DEPICTS THE LOCATION OF EACH MONUMENT
2. ELEVATIONS REFER TO N.G.V.D.

- I ~E

178.3'
113.9'
11.9 -- - - -
12.00' 10.00' 8.00'
8.00 -.
4.00' 1s0.00'
-2.0 0' ~ ~ *

0+00

MEAN HIG1 WATEI (EL 41.20')

3+00




N 0
O IF 00
0
CA)

2+00 3+00 4+00

DISTANCE (FEET)

VERTICAL SCALE 1"=10'-0" HORIZONTAL SCALE 1"=40'-0"

LEGEND:

------- SURVEY #2 (02/10/96)
--- -- SURVEY #4 (08/27/96)

0 10 20 FT.
S40 80 FT.

NOTES:
1. STA. 0+00 DEPICTS THE LOCATION OF EACH MONUMENT
2. ELEVATIONS REFER TO N.G.V.D.

.. I I

U

, 321.4'
-A -- - -i

5+00




go oon las
00
O Z t 0
I )
2
00 Mmi
-o
F
CD

DISTANCE (FEET)

VERTICAL SCALE 1"=10'-0" HORIZONTAL SCALE 1"=40'-0"

LEGEND:

------- SURVEY #2 (02/10/96)
SURVEY #4 (08/27/96)

3 10 20 FT.
0 40 80 FT.

NOTES:
1. STA. 0+00 DEPICTS THE LOCATION OF EACH MONUMENT
2. ELEVATIONS REFER TO N.G.V.D.

- a a

a.

C
z
m
0
0
O" O"

0+00 1+00 2+00

C
z
O1
U,
-<
n so
0
o
0
c
z
0
0

3+00




0
z MD 0 O
n
m(
I
I
0

0+00

108.5' 96.8'

S --. MEAN HIG- WATER (EL 41.21')

1+00

2+00

DISTANCE (FEET)

VERTICAL SCALE 1"=10'-0" HORIZONTAL SCALE 1"=40'-0"

LEGEND:

- - - - SURVEY #2 (02/10/96)
SURVEY #4 (08/27/96)

3 10 20 FT.
3 40 80 FT.
I I

NOTES:
1. STA. 0+00 DEPICTS THE LOCATION OF EACH MONUMENT
2. ELEVATIONS REFER TO N.G.V.D.

- I a

F

12.00' 10.00' 8.00' 6.00'
4.00' 2.00' 0.00'
-2.00'

0
0
z
o1
0
C)
0
C
-<
z
0 c:
o

3+00

=




Re
0
Z W
|r Ii
r
100
-lz

0+00 1+00 2+00

DISTANCE (FEElT)

VERTICAL SCALE 1"=10'-0" HORIZONTAL SCALE 1"=40'-0"

S10 20 FT.
0 40 80 FT.

LEGEND:
--- - SURVEY #1 (12/02/95)
--- -- SURVEY #4 (08/27/96)

NOTES:
1. STA. 0+00 DEPICTS THE LOCATION OF EACH MONUMENT
2. ELEVATIONS REFER TO N.G.V.D.

- U

197.9' 190.3'

3+00

I I




0
2.
I -I
I'm 90
30
00
o
a 10 Xl

C
z
R
m
S
on
0
"t
O
m
o
-<
30
n
o
0
0
c
0
0
z
0
0
z
0

DISTANCE (FEET)

VERTICAL SCALE 1"=10'-0" HORIZONTAL SCALE 1"=40'-0"

LEGEND:
- - - - SURVEY f2 (02/10/96)
--- -- SURVEY #4 (08/27/96)

3 10 20 FT.
D 40 80 FT.

NOTES:
1. STA. 0+00 DEPICTS THE LOCATION OF EACH MONUMENT
2. ELEVATIONS REFER TO N.G.V.D.

I I

-mp

249.5'
12.00'_0 ___ ___ _______221.710.00'
8.00'*
6.00' J-.-.. MEtN HIG- WATER (EL
4.00 %, I 1 -.

0+00 1+00 2+00

3+00




z
90O IF
m
Ug
g0 I3 !z

1+00

2+00

3+00

DISTANCE (FEET)

VERTICAL SCALE 1"=10'-0" HORIZONTAL SCALE 1"=40'-0"

S10 20 FT.
S40 80 FT.
pmmG;2mm;;-I

LEGEND:
------- SURVEY f2 (02/10/96)
--- -- SURVEY #4 (08/27/96)

NOTES:
1. STA. 0+00 DEPICTS THE LOCATION OF EACH MONUMENT
2. ELEVATIONS REFER TO N.G.V.D.

- U

67.3'
64.2'
-'"" __"-" M AN HIG- WATEI (EL 41.23') -

12.00' 10.00' 8.00' 6.00'
4.00' 2.00' 0.00'
-2.00'

0+00

- & I




0
la
1 I.
r 00
0
IN,
20 X 1
cn

C

C
z
m
m
0 on
oc
0
0
0
c
z
0
0
C
z
c

- .1 I

0+00 1+00 2+00

DISTANCE (FEET)

VERTICAL SCALE 1"=10'-0" HORIZONTAL SCALE 1"=40'-0"

LEGEND:

0 10 20 FT.
0 40 80 FT.
pmIw=m

NOTES:
1. STA. 0+00 DEPICTS THE LOCATION OF EACH MONUMENT
2. ELEVATIONS REFER TO N.G.V.D.
3. ACCESS DENIED FOR SURVEY #2.

SURVEY #4 (08/27/96)

3+00




-'U

0*
0
a 1 Ea
-1
00
I
Po 0 z z
00 co

c
n
Q
m
m
0
a
o1
0
0
0
z
0
0
(0 F,
z (1
0
c
z
0

DISTANCE (FEET)

VERTICAL SCALE 1"=10'-0" HORIZONTAL SCALE 1"=40'-0"

LEGEND:

- SURVEY #1

(12/02/95)

0 10 20 FT.
0 40 80 FT.
I FFF !

NOTES:
1. STA. 0+00 DEPICTS THE LOCATION OF EACH MONUMENT
2. ELEVATIONS REFER TO N.G.V.D.
3. ACCESS DENIED DURING SURVEY #2

SURVEY #4 (08/27/96)

_284.0'
251.3 -

1+00 2+00 3+00

4+00

.1




234.9' 148.3'

__ -MEAN HIGH W TER (El- +1.25)

1+00

2+00

3+00

DISTANCE (FEET)

VERTICAL SCALE 1"=10'-0" HORIZONTAL SCALE 1"=40'-0"

3 10 20 FT.
3 40 80 FT.
I !"

LEGEND: NOTES:
- -- - SURVEY #1 (12/02/95) 1. STA. 0+00 DEPICTS THE LOCATION OF EACH MONUMENT
2. ELEVATIONS REFER TO N.G.V.D.
3. ACCESS DENIED FOR SURVEY #2 (ACTIVE BEACH NOURISHMENT
-- SURVEY #4 (08/28/96) PROJECT)

-I

12.00' 10.00' 8.00' 6.00'
4.00' 2.00' 0.00'
-2.00'

0+00




0
,*
IMO

9) O
x
I l
0
Z
31
z
i
I
0 (D
Co

C
z
m
0
On
O
o o2
-<
n
0
zo
o
0
z
0 c:
z
0

DISTANCE (FEET)

VERTICAL SCALE 1"=10'-0" HORIZONTAL SCALE 1"=40'-0"

LEGEND:
------- SURVEY #2 (02/11/96)

0 10 20 FT.
0 40 80 FT.

NOTES:
1. STA. 0+00 DEPICTS THE LOCATION OF EACH MONUMENT
2. ELEVATIONS REFER TO N.G.V.D.

I ----- SURVEY #4 (08/28/96)

t

-324.2'
.. 221.8'
12.00'
10.00' 1

1+00 2+00 3+00

4+00




0 0 z 0
*
1, P 03
-1
M1
Co
0

C
z
O
0
"
O
I
0
0
0
c
Z
0
0
z
(1)
0
;a
C
0
c
z
0
C8

3+00

4+00

DISTANCE (FEET)

VERTICAL SCALE 1"=10'-0" HORIZONTAL SCALE 1"=40"-0"

LEGEND:
--- --------- SURVEY f2 (02/11/96)
--- -- SURVEY #4 (08/28/96)

3 10 20 FT.
0 40 80 FT.

NOTES:
1. STA. 0+00 DEPICTS THE LOCATION OF EACH MONUMENT
2. ELEVATIONS REFER TO N.G.V.D.

U

_312.9' --
256.4'
12.00'
10.00'
8.00' -6.00' "-- - _MEAN HIGI WATER (EL+1. 26')6.00'
4.00" -. - ,
2.00'
0.00-
-2.00' *

2+00

1+00

.5-I




0
Mo
*0 z~I
Re
U)
54
00
00O
0
O
-Il
o)
on

z
m
m co
0 En r
0
*5
C
m
a
Fn
0
o
0
c
z
0
0

VERTICAL SCALE 1"=10'-0 HORIZONTAL SCALE 1"=40'-0"

LEGEND:
------- SURVEY #2 (02/11/96)
--- -- SURVEY #4 (08/28/96)

10 20 FT.
D 40 80 FT.
IIN"

NOTES:
1. STA. 0+00 DEPICTS THE LOCATION OF EACH MONUMENT
2. ELEVATIONS REFER TO N.G.V.D.

- 1m. I

- U
C

294.4' 176.9'

0+50 1+50 2+50
DISTANCE (FEET)

3+50




o 0
no 1 !r rIp
Z so
0 0"
!z
0
on
FO cn
**la

c
z
m
0
on
On
3
0
0
0
c:
C
0
0 U)
z
O1
0
0
"o >!
0
o
z
0
5d

250.2' .
120.3'
-m
_ ---- -- -- --- -- H (
- - J-. ME N HIGH WATER (EL +1. 6')
- *_ s *

1+00

2+00

DISTANCE (FEET)

VERTICAL SCALE 1"=10'-0" HORIZONTAL SCALE 1"=40'-0"

LEGEND:
------- SURVEY #2 (02/11/96)
--- -- SURVEY #4 (08/28/96)

0 10 20 FT.
0 40 80 FT.

NOTES:
1. STA. 0+00 DEPICTS THE LOCATION OF EACH MONUMENT
2. ELEVATIONS REFER TO N.G.V.D.

-1r

12.00 10.00' 8.00' 6.00'
4.00' 2.00' 0.00'
-2.00'

0+00

3+00

- I




.-..I

0
o !e
I
a mo
D0
0
n
My
11a
-I
0O
(n9

c
n
m
<
0
0 30
n
m
0
0
c
0
0
z
0
c
z
0
"i

1+00

2+00

3+00

DISTANCE (FEET)

VERTICAL SCALE 1"=10'-0" HORIZONTAL SCALE 1"=40'-0"

S10 20 FT.
D 40 80 FT.

LEGEND: NOTES:
1. STA. 0+00 DEPICTS THE LOCATION OF EACH MONUMENT
- - - - SURVEY #2 (R-118 UTILIZED) 2. ELEVATIONS REFER TO N.G.V.D.
--- -- SURVEY #4 (08/28/96)

12.00' 810.00' 4.00' 6.00'
4.00' 2.00' 0.00'
-2.00'

186.6'

"----.. ME N HIGH WATER (EL +1 27')

0+00




DISTANCE (FEET)

VERTICAL SCALE 1"=10'-0" HORIZONTAL SCALE 1"=40'-0"

0 10 20 FT.
0 40 80 FT.
a%;; I~

LEGEND: NOTES:
1. STA. 0+00 DEPICTS THE LOCATION OF EACH MONUMENT
--------SURVEY #2 (02/11/96) 2. ELEVATIONS REFER TO N.G.V.D.
3. R-118 PROBABLY REMOVED FROM NEARBY PARKING LOT CONSTRUCTION SURVEY #4 (R-117 UTILIZED) SOMETIME AFTER SURVEY #2 WAS PERFORMED

- p

436.0'

12.00' 10.00' 8.00' 6.00' 4.00'
2.00' 0.00'
-2.00'

-MEAN HIGH W TER (EL. +1.27')-l
_ ___ __- !J_

2+00

3+00

4+00

5+00




0
IF,
z
re
00
aZ
DO
0
W
F cn
h3
I>9

C
z
Z
m
O
0

0
F
P1
0
0
C
Z
z c/)
0
z
O0

VERTICAL SCALE 1"=10'-0" HORIZONTAL SCALE 1"=40'-0"

LEGEND:
---------- SURVEY #2 (02/11/96)
--- -- SURVEY #4 (08/28/96)

D 10 20 FT.
0 40 80 FT.
I !R

NOTES:
1. STA. 0+00 DEPICTS THE LOCATION OF EACH MONUMENT
2. ELEVATIONS REFER TO N.G.V.D.

- II I

451.8'
427.8'
12.00'
10.00'
8.00' L
6..00' ME N HIGH WATER EL
6.00".- --"..'.. .,.
4.00'
2.00' s ,"
0.00'
-2.00'
2+00 3+00 4+00

I,

DISTANCE (FEET)

5+00




0 'o
z I
I W, mr
z 00
I
0

1+00 2+00 3+00

DISTANCE (FEET)

VERTICAL SCALE 1"=10'-0" HORIZONTAL SCALE 1"=40'-0"

3 10 20 FT.
3 40 80 FT.
I !mo

LEGEND:
------- SURVEY #2 (02/10/96)
--- -- SURVEY #4 (08/27/96)

NOTES:
1. STA. 0+00 DEPICTS THE LOCATION OF EACH MONUMENT
2. ELEVATIONS REFER TO N.G.V.D.

MW

L309.4' 305.8'
12.00'
10.00'

4+00

I I




'mr
0
0
O 30
O
-6
0
a M
1
-i
0
F
CA

0+00 1+00 2+00

DISTANCE (FEET)

VERTICAL SCALE 1"=10'-0" HORIZONTAL SCALE 1"=40'-0"

LEGEND:

I
0
0
c
z
o U)
0
0
o
z
0
C

0 10 20 FT.
0 40 80 FT.

NOTES:
1. STA. 0+00 DEPICTS THE LOCATION OF EACH MONUMENT
2. ELEVATIONS REFER TO N.G.V.D.

0 p

L 253.8'
30.7'
12.00' T
10.00'

- - - - SURVEY #2 (02/11/96)
--- -- SURVEY #4 (08/28/96)

3+00

, I




0 130
I
z
0
z
*21

0+00 1+00 2+00

DISTANCE (FEET)

VERTICAL SCALE 1"=10'-0" HORIZONTAL SCALE 1"=40'-0"

3 10 20 FT.
0 40 80 FT.

LEGEND:
- - - - SURVEY #2 (02/10/96)
--- -- SURVEY #4 (08/27/96)

NOTES:
1. STA. 0+00 DEPICTS THE LOCATION OF EACH MONUMENT
2. ELEVATIONS REFER TO N.G.V.D.

-U

178.7' 173.5'

3+00

- & I




0
MO
0
z 0
O 90
p M
C
1

0
-0
;
0)
qI
Fn CA3

C
z
Q
m
0
O
0
m
0
0
4
0
C
z
0
X
z
0

DISTANCE (FEET)

VERTICAL SCALE 1"=10'-0" HORIZONTAL SCALE 1"=40'-0"

LEGEND:
- - - - SURVEY f2 (02/11/96)
--SURVEY #4 (08/28/96)

0 10 20 FT.
S40 80 FT.

NOTES:
1. STA. 0+00 DEPICTS THE LOCATION OF EACH MONUMENT
2. ELEVATIONS REFER TO N.G.V.D.

I

214.0' 211.1'

0+00 1+00 2+00

3+00

.1




0
*0
Re
ar
m
>o 0 0
30
0 .4b,
1.

c
n
m
0
0
0
O
c: UN
z
O
0
U
m
(<
o!
0
z
P1
0

DISTANCE (FEET)

VERTICAL SCALE 1"=10'-0" HORIZONTAL SCALE 1"=40'-0"

LEGEND:
------- SURVEY #2 (02/11/96)
-- -- SURVEY #4 (08/28/96)

0 10 20 FT.
S40 80 FT.
EFFF!

NOTES:
1. STA. 0+00 DEPICTS THE LOCATION OF EACH MONUMENT
2. ELEVATIONS REFER TO N.G.V.D.

- .1~ A

-I

167.9'
164.4'

0+00 1+00 2+00

3+00




a I 0 10 z )p
r
0 01 V Z 30 zz
-0
0
F
;a)

z
m
0
0
n
0
0
0
0
z
P1
0
;a
0
c
z
0

DISTANCE (FEET)

VERTICAL SCALE 1"=10'-0" HORIZONTAL SCALE 1"=40'-0"

LEGEND:
- - - - SURVEY #2 (02/11/96)

3 10 20 FT.
0 40 80 FT.

NOTES:
1. STA. 0+00 DEPICTS THE LOCATION OF EACH MONUMENT
2. ELEVATIONS REFER TO N.G.V.D.

I ----- SURVEY #4 (08/28/96)

150.3'
136.9'

I
C

0+00 1+00 2+00

3+00

-~




0 0
Re
1fp
a
-n
O Z
3 20
1
n
CID

C
z
:2
m
m
0
on
0
0
0
0
C
0
0
z
0
c
z
0

12.00' 10.00' 8.00' 6.00'
4.00' 2.00' 0.00'
-2.00'
0+

3+

172.6'
._ .163.9'
--_ ---_ _--- MEAN HIGH WATER (EL +1 31')
. .......- -

DISTANCE (FEET)

VERTICAL SCALE 1"=10'-0" HORIZONTAL SCALE 1"=40'-0"

LEGEND:
- --- ------ SURVEY #2 (02/11/96)
--- -- SURVEY #4 (08/28/96)

0 10 20 FT.
0 40 80 FT.

NOTES:
1. STA. 0+00 DEPICTS THE LOCATION OF EACH MONUMENT
2. ELEVATIONS REFER TO N.G.V.D.

- I I

I
C

1+00

00

2+00

00




O
so
0
*
IN *
-"
O Z
-I
S0
X
03

C
z
<
m
0
0
on
O I
0
Fn
0
0
a
z
0
0
W
z
0
C
o

2+50

MEAN HIGH W TER (E- +1.32)
--- --

3+50

4+50

DISTANCE (FEET)

VERTICAL SCALE 1"=10'-0" HORIZONTAL SCALE 1"=40'-0"

LEGEND:
------- SURVEY f2 (02/11/96)
--- -- SURVEY f4 (08/28/96)

D 10 20 FT.
0 40 80 FT.
! ITE

NOTES:
1. STA. 0+00 DEPICTS THE LOCATION OF EACH MONUMENT
2. ELEVATIONS REFER TO N.G.V.D.

I
C

322.3'
S 319.7'

12.00" 10.00' 8.00' 6.00'
4.00'
2.00' 0.00'
-2.00'

5+50

I

immmm




0
MO
0 z 0
0
go a 0
-gi5
is
3
-o
0
cn
0)
CD

C
z
m
0
0
*gg
0
0
z
0
0
C
z
0
c:
O
> 59
O: O0

3+00

DISTANCE (FEET)

VERTICAL SCALE 1"=10'-0" HORIZONTAL SCALE 1"=40'-0"

LEGEND:
- - - - SURVEY #2 (02/11/96)
--- -- SURVEY #4 (08/28/96)

0 10 20 FT.
0 40 80 FT.

NOTES:
1. STA. 0+00 DEPICTS THE LOCATION OF EACH MONUMENT
2. ELEVATIONS REFER TO N.G.V.D.

a m -

V

-203.4' 190.7'
12.00' 10.00' 8.00' 6.00'
2.00' .
-2.00' --

2+00

1+00




0 50 ze
'am4
Tip
r 00
-I
0
30
n
%4

C
z
m
0
an
0
r
O
0
O
Z
0
0
z
0
0
0
C
z
0

DISTANCE (FEET)

VERTICAL SCALE 1"=10'-0" HORIZONTAL SCALE 1"=40'-0"

LEGEND:

- - - - SURVEY #2 (02/11/96)
--- -- SURVEY #4 (08/28/96)

3 10 20 FT.
S40 80 FT.

NOTES:
1. STA. 0+00 DEPICTS THE LOCATION OF EACH MONUMENT
2. ELEVATIONS REFER TO N.G.V.D.

_- 179.1'
175.0'

1+00 2+00 3+00

I




0 Z0
SO
r 00
10 30
X
q
0

0+00 1+00 2+00

DISTANCE (FEET)

VERTICAL SCALE 1"=10'-0" HORIZONTAL SCALE 1"=40'-0"

LEGEND:

- - - - SURVEY #2 (02/12/96)
- -SURVEY #4 (08/28/96)

0 10 20 FT.
0 40 80 FT.
! In

NOTES:
1. STA. 0+00 DEPICTS THE LOCATION OF EACH MONUMENT
2. ELEVATIONS REFER TO N.G.V.D.

I I

U

182.0'

0
0
c
z
0
0
W
z
0
;a

3+00




0
O 11 IF,
0
I-W 30

1+00

2+00 3+00

DISTANCE (FEET)

VERTICAL SCALE 1"=10'-0" HORIZONTAL SCALE 1"=40'-0"

3 10 20 FT.
3 40 8I FT.
040 80 FT.

LEGEND:
------- SURVEY #2 (02/12/96)
--- -- SURVEY #4 (08/28/96)

NOTES:
1. STA. 0+00 DEPICTS THE LOCATION OF EACH MONUMENT
2. ELEVATIONS REFER TO N.G.V.D.

--

S238.0' 221.5'
12.00' 10.00' 8.00' 6.00'
4.00' ,
2.00' --.._0.00'
-2.00'

4+00

- I I




0 0
O I3
00
1
40
I!
CA
4 ;a (A

C
z
m
0
on Ufl
0
m
a
4
o
0
0
z
0
0
z
0

VERTICAL SCALE 1"=10'-0" HORIZONTAL SCALE 1"=40'-0"

LEGEND:
------- SURVEY #2 (02/12/96)
SURVEY #4 (08/28/96)

3 10 20 FT.
3 40 80 FT.

NOTES:
1. STA. 0+00 DEPICTS THE LOCATION OF EACH MONUMENT
2. ELEVATIONS REFER TO N.G.V.D.

U

0+00 1+00 2+00

DISTANCE (FEET)

3+00

I

.




0
Re ) Itl
la
i
O Z
3
0
I to
0)

C
z
m
<
0
SC
0
F1
0
0
0
0
z
rri U)
o!
0
c
z

VERTICAL SCALE 1"=10'-0" HORIZONTAL SCALE 1"=40'-0"

LEGEND:
------- SURVEY #2 (02/12/96)
--- -- SURVEY #4 (08/28/96)

0 10 20 FT.
0 40 80 FT.

NOTES:
1. STA. 0+00 DEPICTS THE LOCATION OF EACH MONUMENT
2. ELEVATIONS REFER TO N.G.V.D.

- I

r
C

0+00 1+00 2+00

DISTANCE (FEET)

3+00




z
Bo
00
z I0W
-1'

DISTANCE (FEET)

VERTICAL SCALE 1"=10'-0" HORIZONTAL SCALE 1"=40'-0"

0 10 20 FT.
S40 80 FT.
I!TM

LEGEND:
------- SURVEY f2 (02/12/96)
--- -- SURVEY #4 (08/28/96)

NOTES:
1. STA. 0+00 DEPICTS THE LOCATION OF EACH MONUMENT
2. ELEVATIONS REFER TO N.G.V.D.

-I

_ 925.2'
921.3'
12.00' 10.00' 8.00' 6.00'
4.00'
2.00'
0.00'
-2.00'
8+00 9+00

MEAN HIGI WATE (EL. + .39')

- -~- -

10+00

11+00

I I




110.5'
104.6'
---.""'- ..., -MEAN HIGH W kTER (E. +1.39')
- - -- -..- -

12.00' 10.00' 8.00' 6.00'
4.00' 2.00' 0.00'
-2.00'
0+

2+00

DISTANCE (FEET)

VERTICAL SCALE 1"=10'-0" HORIZONTAL SCALE 1"=40'-0"

3 10 20 FT.
3 40 80 FT.
I I"

LEGEND: NOTES:
1. STA. 0+00 DEPICTS THE LOCATION OF EACH MONUMENT
- - - - SURVEY #2 (02/12/96) 2. ELEVATIONS REFER TO N.G.V.D.
--- -- SURVEY #4 (08/28/96)

-U

1+00

3+00

00




0 so z 10
e.
r
E,i
00
Ez
* Z
0
0
1
x
F
W
i)

C
z
m
0
OF 91

0
O
F
O
C
0
0
c
z
0
o)
0
z
0
;u

0+00

1+00

2+00

DISTANCE (FEET)

VERTICAL SCALE 1"=10'-0" HORIZONTAL SCALE 1"=40'-0"

LEGEND:

SURVEY #1 (12/03/95) SURVEY f2 (MONUMENT GONE) SURVEY #3 (MONUMENT GONE) SURVEY f4 (MONUMENT GONE)

S10 20 FT.
D 40 80 FT.

NOTES:
1. STA. 0+00 DEPICTS THE LOCATION OF EACH MONUMENT
2. ELEVATIONS REFER TO N.G.V.D.

-I
C

12.00' 10.00' 8.00' 6.00'
4.00' 2.00' 0.00'
-2.00'

30.7' -

MEAN HIGH WAI ER (EL +1.40')

3+00

I

,




-n

0 MO
0
M Z
on 6
x
so
-I
mU
F

C
z
m
m
0 on r"
0
O
F
o
C
0
0
a
z
0
0
z
m
C

VERTICAL SCALE 1"=10'-0= HORIZONTAL SCALE 1"=40'-0"

LEGEND:

- - - - SURVEY #2 (02/12/96)
- - SURVEY #4 (08/27/96)

D 10 20 FT.
0 40 80 FT.

NOTES:
1. STA. 0+00 DEPICTS THE LOCATION OF EACH MONUMENT
2. ELEVATIONS REFER TO N.G.V.D.

- & I

0+00 1+00 2+00

DISTANCE (FEET)

3+00




~1

z
mo 2 r 00
ai Ill
V
0
F
(I)
(0

c
z
Q
m
m
0
a
On
o
>
0
0
0
a
z
0
0
C
z
0
C

MEAN HIGH WATER (EL +1.41')
"-- - - -

1+00

2+00

3+00

DISTANCE (FEET)

VERTICAL SCALE 1"=10'-0" HORIZONTAL SCALE 1"=40'-0"

LEGEND:

---------- SURVEY #2 (02/12/96)
--- -- SURVEY #4 (08/27/96)

0 10 20 FT.
3 40 80 FT.

NOTES:
1. STA. 0+00 DEPICTS THE LOCATION OF EACH MONUMENT
2. ELEVATIONS REFER TO N.G.V.D.

- I I

12.00' 10.00' 8.00' 6.00'
4.00'
2.00'
0.00'
-2.00'

L- --

34.4'

0+00




0
i
0
ZI 3
O
2.
3 I
100
0
-I
CA

1+00

2+00

3+00

DISTANCE (FEET)

VERTICAL SCALE 1"=10'-0" HORIZONTAL SCALE 1"=40'-0"

LEGEND:
------------ SURVEY #1 (11/18/95)
- - SURVEY #4 (08/27/96)

0 10 20 FT.
0 40 80 FT.

NOTES:
1. STA. 0+00 DEPICTS THE LOCATION OF EACH MONUMENT
2. ELEVATIONS REFER TO N.G.V.D.

~I~5

-U

]25.9'
12.00'10.00'
8.00'
6.00'
4.00' 4r.00' MEAN HIGH WATER (E. +1.41')
2.00
-2.00'
-.0'-

0+00

F mr
0
0
c
0
0
CA
z
0
z
0




- U
C

90 >0 la 1
I
e 00 .Z
-1
t0
0
n

z
m
m
0 o1
*11 "
0
O
0
0
C
Z
z
0
0
c
z
0
oC

DISTANCE (FEET)

VERTICAL SCALE 1"=10'-0" HORIZONTAL SCALE 1"=40'-0"

LEGEND:
- - - - SURVEY #2 (02/12/96)
--- -- SURVEY #4 (08/28/96)

0 10 20 FT.
0 40 80 FT.

NOTES:
1. STA. 0+00 DEPICTS THE LOCATION OF EACH MONUMENT
2. ELEVATIONS REFER TO N.G.V.D.

338.6'
338.6'

2+00 3+00 4+00

5+00

I

J




0
-o
I r
00
30 1
+ b

z
m
x
0 On an
I
0
C
0
0
O
z 01
0 c)
z
0
C

S" FMEAN HIGH WATER EL +1.43')
' .-.

2+00

DISTANCE (FEET)

VERTICAL SCALE 1"=10'-0" HORIZONTAL SCALE 1"=40'-0"

LEGEND:
- SURVEY #2 (02/12/96)
- - SURVEY #4 (08/28/96)

0 10 20 FT.
0 40 80 FT.

NOTES:
1. STA. 0+00 DEPICTS THE LOCATION OF EACH MONUMENT
2. ELEVATIONS REFER TO N.G.V.D.

- I a

12.00' 10.00' 8.00' 6.00'
4.00' 2.00' 0.00'
-2.00'

0+00

(FOR BOTH)
169.1'

C

1+00

3+00




,0
z
so
-IF on It p 90
l
o
0
U,)
-I
(0

C
z
m
m
0 on
0
Fi
0
0
c
0
0
z
0
z
<

DISTANCE (FEET)

VER11CAL SCALE 1"=10'-0" HORIZONTAL SCALE 1"=40'-0"

LEGEND:

---------- SURVEY f2 (02/12/96)
SURVEY #4 (08/28/96)

0 10

NOTES:
1. STA. 0+00 DEPICTS THE LOCATION OF EACH MONUMENT
2. ELEVATIONS REFER TO N.G.V.D.

- a a

I

263.5' 251.3'
12.00'

1+00 2+00 3+00

4+00

20 FT.
80 FT. 80 FT.




Appendix B 1
Data Analysis of Aerial Survey Data taken on
February 5, 1996




LEE COUNTY COASTLINE STUDY
GASPARILLA ISLAND
February 1996 Survey Information Calibrated Utilizing Raw Data
Raw Data Calibration Utilizing Calibration Utilizing
DNR Ground High Water Line Error Without The First and Last Monument of the Island Every Other Monument of the Island
Monument Truth Position Wihout Correction Interpolation Calibration High Water Line Error Interpolation Calibration High Water Line Error
(Feet) Correction (Feet) Number Coefficient Position (Feet) (Feet) Number Coefficient Position (Feet) (Feet)
R-1 189.7 193.0 3.3 3.3 189.7 0.0 3.3 189.7 0.0
R-2 205.5 1 2.5 203.0 1 3.3 202.2
R-3 168.8 2 1.8 167.0 2 3.4 165.4
R-4 235.9 3 1.0 234.9 3 3.5 232.4
R-5 220.9 4 0.3 220.6 4 3.5 217.4
R-6 140.7 124.1 -16.6 5 -0.4 124.5 -16.2 5 3.6 120.5 -20.2
R-7 214.3 6 -1.2 215.4 6 3.7 210.6
R-8 118.3 7 -1.9 120.2 7 3.7 114.6
R-9 306.7 8 -2.7 309.4 8 3.8 303.0
R-10 218.2 9 -3.4 221.6 9 3.9 214.3
R-1 1 43.6 10 -4.2 47.8 10 3.9 39.7
R-12 55.3 59.3 4.0 11 -4.9 64.2 8.9 11 4.0 55.3 0.0
R-13 27.1 12 -5.7 32.7 1 3.8 23.3
R-14 13 -6.4 2 3.5
R-15 14 -7.1 3 3.3
R-16 227.5 15 -7.9 235.4 4 3.1 224.3
R-17 257.2 245.5 -11.7 16 -8.6 254.1 -3.1 5 2.9 242.6 -14.6
R-18 329.7 17 -9.4 339.1 6 2.7 327.0
R-19 162.6 18 -10.1 172.7 7 2.5 160.1
R-20 275.0 19 -10.9 285.9 a 2.3 272.8
R-21 146.6 148.6 2.0 20 -11.6 160.3 13.7 9 2.0 146.6 0.0
R-22 376.5 21 -12.4 388.9 2.0 374.5
R-23 70.1 22 -13.1 83.2 2.0 68.1
R-24 118.0 23 -13.9 131.8 2.0 115.9
R-25 24 -14.6 2.0
R-26 225.7 210.4 -15.3 25 -15.3 225.7 0.0 2.0 208.3 -17.4
Average Error: -5.7 Avg. 0.8 Avg. -17.4
Standard Deviation: 9.8 S.D. 13.3 S.D. 2.8
Note: The monuments at which ground truth profiles are located are shown in bold type.




LEE COUNTY COASTLINE STUDY
GASPARILLA ISLAND
February 1996 Survey Information Calibrated Utilizing Average Error Correction
Raw Data Error Correction Calibration Utilizing Calibration Utilizing
DNR Ground High Water Line Error Without High Water Line ErrorWith Avg. The First and Last Monument of the Island Ever Other Monument of the Island
Monument Truth PositionWithout Correction PositionWrib ErrorCorrection Interpolation Calibration HighWaterLine Error Interpolation Calibration HighWaterLine Error
(Feet) Correction (Feet) Avg Error Correction (Feet) Number Coefficient Position (Feet) (Feet) Number Coefficient Position (Feet) (Feet)
R-1 189.7 193.0 3.3 198.7 9.0 9.0 189.7 0.0 9.0 189.7 0.0
R-2 205.5 211.3 1 8.3 203.0 1 9.1 202.2
R-3 168.8 174.5 2 7.5 167.0 2 9.1 1654
R4 235.9 241.6 3 6.8 234.9 3 9.2 2324
R-5 220.9 226.7 4 6.0 220.6 4 9.3 217.4
R4 140.7 124.1 -16.6 129.8 -10.9 5 8.3 124.8 -16.2 6 6.3 120.5 *20.2
R-7 214.3 220.0 6 45 215.4 6 9.4 210.6
R-8 118.3 124.0 7 3.8 120.2 7 9.4 114.6
R.0 306.7 312.5 8 3.0 309.4 8 9.5 303.0
R-10 218.2 223.9 9 2.3 221.6 9 9.6 214.3
R-11 43.6 49.3 10 1.6 47.8 10 9.6 39.7
R-12 553 59.3 4.0 65.0 0.7 11 0.8 64.2 8.9 11 9.7 S5.3 0.0
R-13 27.1 32.8 12 0.1 32.7 1 9.5 23.3
R-14 13 -0.7 2 9.3
R-s15 14 -1.4 3 9.1
R-16 227.5 233.2 15 -.2 235.4 4 8.8 224.3
R-17 257.2 245.5 -11.7 251.2 -6.0 16 -2.A 254.1 -3.1 5 8.6 242.6 -14.6
R-18 329.7 335.4 17 -3.7 339.1 6 8.4 327.0
R-19 162.6 168.3 18 -4.4 172.7 7 8.2 160.1
R-20 275.0 280.7 19 -5.1 285.9 8 8.0 272.8
R-21 146.6 148.6 20 154A 7.8 20 -4.9 160.3 13.7 9 78 146.8 0.0
R-22 376.5 382.2 21 -6.6 388.9 7.8 374.5
R-23 70.1 75.8 22 -7.4 83.2 7.8 68.1
R-24 118.0 123.7 23 -8.1 131.8 7.8 115.9
R-25 24 -8.9 7.8
R-26 225.7 210.4 -15.3 216.1 -.6 25 -9.6 225.7 0.0 7.6 208.3 -17.4
Average Error: -5.7 Avg. 0.0 Avg 0.8 Avg. -17.4
Standard Devlation: 9.8 S.D. 9. S.D. 13.3 S.D. 2.8
Note: The monuments at which ground truth profiles are located are shown In bold type.




C-19

-n
(D
R
c 03
Cl)
fm
1 5
CL 0)




LEE COUNTY COASTLINE STUDY
LACOSTA ISLAND
February 1996 Survey Information Calibrated Utilizing Raw Data
Raw Data Calibration Utilizing Calibration Utilizing
DNR Ground High Water Line Error Without The First and Last Monument of the Island Every Other Monument of the Island
Monument Truth Position Without Correction Interpolation Calibration High Water Line Error Interpolation Calibration High Water Line Error
(Feet) Correction (Feet) Number Coefficient Position (Feet) (Feet) Number Coefficient Position (Feet) (Feet)
I r T I" 4

R-27
R-28 R-29
R-30
R-31 R-32
R-33 R-34
R-35 R-37 R-38 P,-39
R-40
R-41
R-42
R-43 R-44 R-45
R-48 R-47 R-41 R-49 R-50 R-51
R-52 R-53
R-54
R-55 R-56
R-57
R-58 R-S9
R-60
R-61 R-62 R-63
R-65

16.4 133.6 199.3
62.2 112.4
2532 319.1 442.8
646.5 829.4
2094.2 2030.4 1605.8
1409.2 1672.5 1503.5 1158.7 869.7 577.3
179.4 114.5 111.5 22.2
41.7 181.0
185.9 318.7 717.6 697.2
490.9 291.9 168.8 77.13 30.95 89.5
34.25 78.2
24.2 52.16

21.1

1
2
3
4
8
6
7
8
9 10 11 12 13
14 15
16
17 18 19
20
21 22 23 24 25 26 27
28 29 30o 31 32 33
34 35

21.1 21.1 21.1 18.4 15.7 13.1
10.4 7.7 5.0 2.3
-0.3
-3.0
-5.7
-8.4
-11.0
-13.7
-16.4
-19.1
-21.7
-24.4
-27.1
-29.8
-32.5
-35.1
-37.8
-40.5
-43.2
-45.8
-48.5
-51.2
-53.9
-56.5
-59.2
-61.9
-64.6
-67.2
-69.9
-72.6
-72.6

-4.7
112.5 178.2
43.8 96.6
240.1 308.7 435.1
641.5 827.1
2094.5 2033.4 1611.5
1417.5 1683.5 1517.2 1175.1 888.8 5699.0 203.8
141.6 141.3 54.7 76.8
218.8 226.4 361.9 763.4 745.7 542.1
345.8 225.3 136.3 92.8
154.1 101.5
148.1 96.8
124.8

0.0
-33.9
36.8 27.4
40.5 63.9 0.0

0.0
-45.4
0.0
-10.8
0.0
45.6 0.0

AverageError: -9.0 Avg. 26.9 Avg. -3.6
Standard Devifation: 31.9 S.D. 36.6 S.D. 45.9

Note: The monuments at which ground truth profiles are located are shown in bold type.




LEE COUNTY COASTLINE STUDY
LACOSTA ISLAND
February 1996 Survey Information Calibrated Utilizing Average Error Correction
Raw Data Error Correction Calibration Utilizing Calibration Utilizing
DNR Ground High Water Line Error Without High Water Line Error With Avg. The First and Last Monument of the Island Every Other Monument of the Island
Monument Truth PositionWithout Correction Positon With Error Correction Interpolation Calibration High Water Line Error Interpolation Calibration HighWater Line Error
(Feet) Correction (Feet) Avg Error Correction (Feet) Number Coefficient Position (Feet) (Feet) Number Coefficient Position (Feet) (Feet)
R-27 16.4 254 30.1 -4.7 30.1 -4.7
R-28 133.6 142.6 30.1 112.5 30.1 112.5
R-29 178.2 199.3 21.1 208.3 30.1 30.1 178.2 0.0 30.1 178.2 0.0
R-30 62.2 71.2 1 27.4 43.8 1 29.7 41.5
R-31 112.4 121.3 2 24.7 96.6 2 29.3 92.0
11R-32 253.2 262.1 3 22.0 240.1 3 29.0 233.2
R-33 319.1 328.1 4 19.4 308.7 4 28.6 299.5
R-34 469.0 442.8 -26.2 461.8 -17.2 6 18.7 436.1 -33.8 5 282 423.8 -46.4
R-35 646.5 65.5 6 14.0 641.5 6 27.8 627.7
R-36 829.4 838.4 7 11.3 827.1 7 27.5 810.9
R-37 2094.2 2103.2 8 8.7 20945 8 27.1 2076.1
R-38 2030.4 20394 9 6.0 2033.4 9 26.7 2012.7
R-39 1605.8 1614.8 10 3.3 1611.5 10 26.3 1588.5
R-40 1409.2 1418.2 11 0.6 1417.5 11 26.0 1392.2
R-41 1672.5 1681.5 12 -2.0 1683.5 12 25.6 1655.9
R-42 1503.5 1512.5 13 -4.7 1517.2 13 25.2 1487.3
R-43 1158.7 1167.7 14 -7.4 1175.1 14 24.8 1142.9
R-44 869.7 878.7 15 -10.1 8888 15 24.5 854.2
R-45 52.2 577.3 15.1 588.3 24.1 18 -12.7 5699.0 3868 1 24.1 882.2 0.0
R-48 179.4 188.4 17 -15.4 203.8 1 21.9 166.5
R-47 114.5 123.5 18 -18.1 141.8 2 19,6 103.9
R-48 113.8 1115 -2.4 120.5 8.8 19 -20.8 1413 27.4 3 17.4 103.1 -10.8
R49 22.2 31.2 20 -235 54.7 4 15.2 16.0
R-50 41.7 50.7 21 -26.1 76.8 5 13.0 37.7
R-51 181.0 100.0 22 -28.8 218.8 6 10.7 179.3
R-52 185.9 194.9 23 -31.5 226.4 7 8.5 186.4
R43 321.4 318.7 -2.7 327.7 8.3 24 -34.2 381.8 40.5 8 8.3 321.4 0.0
R-54 717.6 726.6 25 -36.8 763.4 1 -0.1 726.7
R-55 697.2 706.2 26 -39.5 745.7 2 -6.4 712.6
R-56 490.9 499.9 27 42.2 542.1 3 -12.8 512.7
R-57 201.9 300.9 28 -44.9 345.8 4 -19.1 320.0
R-58 168.8 177.8 29 -47.5 225.3 5 -25.5 203.3
R-9 72.4 77.13 4.7 88.1 13.7 30 -602 138.3 63.9 6 -31.8 118.0 45.6
R-60 30.95 39.9 31 -52.9 92.8 7 -38.2 78.1
R-61 89.5 985 32 -55.6 154.1 8 -44.5 143.0
R-62 34.25 43.2 33 -58.2 101.5 9 -50.9 94.1
R-63 78.2 87.2 34 -60.9 148.1 10 -57.2 144.4
R-44 96.8 24.2 -72.6 332 -43. 35 43.8 8.8 0.0 11 43.8 96.8 0.0
R-65 52.16 61.2 -63.6 124.8 -63.6 124.8
SA V.P aPA

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LEE COUNTY COASTLINE STUDY
NORTH CAPTIVA ISLAND
February 1996 Survey Information Calibrated Utilizing Raw Data
Raw Data Calibration Utilizing
DNR Ground High Water Line Error Without The First and Last Monument of the Island
Monument Truth Position Without Correction Interpolation Calibration High Water Line Error
(Feet) Correction (Feet) Number Coefficient Position (Feet) (Feet)
R-66 161.9 6.3 155.7
R-67 376.4 6.3 370.1
R-68 121.4 6.3 115.1
R-69 190.3 196.6 6.3 6.3 190.3 0.0
R-70 241.9 1 5.1 236.8
R-71 332.9 2 3.8 329.1
R-72 581.3 3 2.6 578.7
R-73 1025.4 4 1.4 1024.0
R-74 579.5 5 0.1 579.4
R-74A 430.8 6 -1.1 431.9
R-75 221.7 220.0 -1.7 7 -2.3 222.3 0.6
R-75A 60.4 8 -3.6 64.0
R-76 9 -4.8
R-76A 7.4 10 -6.0 13.4
R-77A 27.1 11 -7.2 34.3
R-78 64.2 55.7 -8.5 12 -8.5 64.2 0.0
R-79 104.4 -8.5 112.9
R-79A 89.8 -8.5 98.3
R-80 -8.5
R-81 71.0 -8.5 79.5
R-81A -8.5
R-82 216.5 -8.5 225.0
Average Error: -1.3
Standard Deviation: 7.4
Note: The monuments at which ground truth profiles are located are shown in bold type.




LEE COUNTY COASTLINE STUDY
NORTH CAPTIVA ISLAND
February 1996 Survey Information Calibrated Utilizing Average Error Correction
Raw Data Error Correction Calibration Utilizing
DNR Ground High Water Line Error Without High Water Line Error With Avg. The First and Last Monument of the Island
Monument Truth Position Withoui Correction Position Wit Error Correction Interpolation Calibration High Water Line Error
______ (Feet) Correction (Feet) Avg Error Correction (Feet) Number Coefficient Position (Feet) (Feet)
R-66 161.9 163.3 7.6 155.7
R-67 376.4 377.7 7.6 370.1
R-68 121.4 122.7 7.6 115.1
R-69 190.3 196.6 6.3 197.9 7.6 7.6 190.3 0.0
R-70 241.9 243.2 1 6.4 236.8
R-71 332.9 334.2 2 5.1 329.1
R-72 581.3 582.7 3 3.9 578.7
R-73 1025A 1026.7 4 2.7 1024.0
R-74 579.5 580.8 5 1.4 579.4
R-74A 430.8 432.1 6 0.2 431.9
R-75 221.7 220.0 -1.7 221.3 -0.4 7 -1.0 222.3 0.6
R-75A 60.4 61.7 8 -2.2 64.0
R-76 9 -3.5
R-76A 7.4 8.7 10 -4.7 13.4
R-77A 27.1 28A 11 -5.9 34.3
R-78 64.2 55.7 -8.5 57.0 -7.2 12 -7.2 64.2 0.0
R-79 104.4 105.7 -7.2 112.9
R-79A 89.8 91.1 -7.2 98.3
R-80 -7.2
R-81 71.0 72.3 -7.2 79.5
R.81A -7.2
R-82 216.5 217.8 -7.2 225.0
Average Error: -1.3 Avg. 0.0
Standard Deviation: 7.4 S.D. 7.4____ ______________Note: The monuments at which ground truth profiles are located are shown in bold type.




LEE COUNTY COASTUNE STUDY
NORTH CAPTIVA ISLAND
February 1996 Survey Information Calibrated Utilizing Tidal Correction
Raw Data Corrected Data For Tidal Differences Calibration Utilizing
DNR Ground High Water Line Error Without Tidal Corrections High Water Line Error With The First and Last Monument of the Island
Monument Truth Position Without Correction Tidal Elevation Slope Within High Water Line Position With Tidal Correction Interpolation Calibration High Water Line Error
(Feet) Correction (Feet) Correction Swash Zone Correction Tide Correction (Feet) Number Coefficient Position (Feet) (Feet)
R-66 161.9 -0.12 0.116 1.0 163.0 7.3 155.7
R-67 376.4 -0.12 0.116 1.0 377.4 7.3 370.1
P-e 121.4 -0.12 0.116 1.0 122.5 7.3 115.1
P-9 190.3 196.6 6.3 -0.12 0.116 1.0 197.6 7.3 7.3 190.3 0.0
R-70 241.9 -0.12 0.109 1.1 243.0 1 6.1 236.9
1-4I 332.9 -0.12 0.102 1.2 334.1 2 4.9 329.2
n-72 581.3 -0.12 0.096 1.3 582.6 3 3.7 578.9
R-73 1025.4 -0.12 0.089 1.3 1026.8 4 2.5 1024.3
R-74 579.5 -0.12 0.082 1.5 581.0 5 1.3 579.7
R-74A 430.8 -0.12 0.076 1.6 432.4 6 0.1 432.3
R-75 221.7 220.0 -1.7 -0.12 0.060 1.7 221.7 0.0 7 -1.1 222.A 1.1
R-75A 60.4 -0.12 0.074 1.6 62.0 6 -2.4 64.4
R-76 -0.12 0.079 9 -3.6
R-76A 7.4 -0.12 0.084 1.4 8.8 10 -4.8 13.6
R-77A 27.1 -0.12 0.089 1.3 28.4 11 -6.0 34.4
R-7 64.2 65.7 -8.5 -0.12 0.094 1.3 57.0 -7.2 12 -7.2 64.2 0.0
R-79 104.4 -0.12 0.094 1.3 108.6 -7.2 112.9
R-79A 69.8 -0.12 0.094 1.3 91.1 -7.2 98.3
R-80 -0.12 0.094 -7.2
R-s1 71.0 -0.12 0.094 1.3 72.2 -7.2 79.5
R-81A -0.12 0.094 -7.2
R-82 216.5 -0.12 0.094 1.3 217.8 -7.2 225.0
Average Error -1.3 Avg. 0.0
Standad Deviatiorn 7.4 S.D. 7.3
Note: The monuments at which ground truth profiles are located are shown in bold type.




LEE COUNTY COASTLINE STUDY
CAPTIVA ISLAND
February 1996 Survey Information Calibrated Utilizing Raw Data
Raw Data Calibration Utilizing Calibration Utilizing
DNR Ground High Water Line Error Without The First and Last Monument of the Island Every Other Monument of the Island
Monument Truth Position Without Correction Interpolation Calibration High Water Line Error Interpolation Calibration High Water Line Error
(Feet) Corredion (Feet) Number Coefficient Position (Feet) (Feet) Number Coefficient Position (Feet) (Feet)
A-46-2 126.1 6.2 119.9 6.2 119.9
R-85 833.3 6.2 827.1 6.2 827.1
R-86 520.0 6.2 513.8 6.2 513.8
R-87 383.4 6.2 377.2 6.2 377.2
R-88 251.3 257.5 6.2 6.2 251.3 0.0 6.2 251.3 0.0
R-89 453.9 1 4.9 449.0 1 6.6 447.3
R-90 215.1 2 3.6 211.5 2 6.9 208.2
R-91 157.5 3 2.3 155.2 3 7.3 150.2
R-92 192.2 4 1.0 191.2 4 7.7 184.5
R-93 224.8 5 -0.3 225.1 5 8.1 216.7
R-94 148.3 153.3 5.0 6 -1.6 154.9 6.6 6 8.4 144.9 -3.4
R-95 148.3 7 -2.9 151.2 7 8.8 139.5
R-96 117.7 8 -4.2 121.9 8 9.2 108.5
R-97 108.7 9 -5.5 114.2 9 9.6 99.1
R-98 130.1 10 -6.8 136.9 10 9.9 120.2
R-99 221.8 232.1 10.3 11 -8.1 240.2 18.4 11 10.3 221.8 0.0
R-100 194.0 12 -9.4 203.4 1 7.0 187.0
R-101 277.0 13 -10.7 287.7 2 3.6 273.4
R-102 219.0 14 -12.0 231.0 3 0.3 218.7
R-103 275.0 15 -13.3 288.3 4 -3.1 278.1
R-104 256.4 268.1 11.7 16 -14.6 282.7 26.3 5 -6.4 274.5 18.1
R-105 156.8 17 -15.9 172.7 6 -9.8 166.6
R-106 425.3 18 -17.2 442.5 7 -13.1 438.4
R-107 429.4 19 -18.5 447.9 8 -16.5 445.9
R-1068 176.9 157.1 -19.8 20 -19.8 176.9 0.0 9 -19.8 176.9 0.0
R-109 374.2 -19.8 394.0 -19.8 394.0
Average Error: 2.7 Avg. 17.1 Avg. 7.3
Standard Deviation: 12.9 S.D. 9.9 S.D. 15.2
Note: The monuments at which ground truth profiles are located are shown in bold type.




LEE COUNTY COASTLINE STUDY
CAPTIVA ISLAND
February 1996 Survey Information Calibrated Utilizing Average Error Correction
Raw Data Error Correction Calibration Utilizing Calibration Utilizing
DNR Ground High Water Line Error Without High Water Line Error With Avg. The First and Last Monument of the Island Ever Other Monument of the Island
Monument Truth Position Without Correction Position Withb Error Correction Interpolation Calibration High Water Line Error Interpolation Calibration High Water Line Error
(Feet) Correction (Feet) Avg Error Correction (Feet) Number Coefficient Position (Feet) (Feet) Number Coefficient Position (Feet) Feet)
A-46-2 126.1 123.4 3.5 119.9 3.5 119.9
R-85 833.3 830.6 3.5 827.1 3.5 827.1
R-88 520.0 517.3 3.5 513.8 3.5 513.8
R-87 383.4 380.7 3.5 377.2 3.5 377.2
R-88 251.3 257.8 6.2 254.8 3.5 3.5 251.3 0.0 3. 251.3 0.0
R-89 453.9 451.2 1 2.2 449.0 1 3.9 447.3
R-90 215.1 212.4 2 0.9 211.5 2 4.3 208.2
R-91 157.5 154.8 3 -0.4 1552 3 4.6 150.2
R-92 1922 189.5 4 -1.7 191.2 4 5.0 184.5
R-93 224.8 222.1 5 -3.0 225.1 5 54 216.7
R-04 148.3 183.3 8.0 150.6 2.3 8 -4.3 164.6 8.6 8 5.8 144.8 -3.4
R-95 148.3 145.6 7 -5.8 151.2 7 6.1 139.5
R-96 117.7 115.0 8 -6.9 121.9 8 0.5 108.5
1R1-97 108.7 106.0 9 -8.2 114.2 9 6.9 99.1
R-98 130.1 127.4 10 -9.5 138.9 10 7.2 120.2
R.9 221.8 232.1 10.3 229.4 7.6 11 -10.8 240.2 18.4 11 7.6 221.8 0.0
R-100 194.0 191.3 12 -12.1 203.4 1 4.3 187.0
11-101 277.0 274.3 13 -13.4 287.7 2 0.9 273.4
R-102 219.0 218.3 14 -14.7 231.0 3 -2.4 218.7
11-103 275.0 272.3 15 -16.0 288.3 4 -5.8 278.1
R-104 256.4 268.1 11.7 265.4 9.0 18 -17.3 282.7 2.3 8 -9.1 274.5 18.1
R-105 156.8 154.1 17 -18.6 172.7 6 -124 166.6
R-106 425.3 422.6 18 -19.9 442.5 7 -15.8 438.4
R-107 429.4 426.7 19 -21.2 447.9 8 -19.1 445.9
R-108 176.0 157.1 -19.8 154.4 -225 20 -22.5 176.9 0.0 8 -22.5 178.9 0.0
R-109 374.2 371.5 -22.5 394.0 -22.5 394.0
Average Error: 2.7 Avg. 0.0 Avg. 17.1 Avg, 7.3
Standard Devlatilon: 12.9 S.D. 12.9 S.D. 9.0 S.D. 15.2
Note: The monuments at which ground truth profiles are located are shown In bold type.




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