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UFL/COEL-93/005
PERDIDO KEY BEACH NOURISHMENT PROJECT:
GULF ISLANDS NATIONAL SEASHORE
1992 Annual Report
by
Emre N. Otay
and
Robert G. Dean
September, 1993
Sponsor:
Department of the Navy
Southern Division
Naval Facilities Engineering Command
Charleston, SC 29411-0068
REPORT DOCUMENTATION PAGE
X. Report No. 2. 3. Recipleat' Ac esrelo no.
S. Tilei and Subtitle ~. lport Date
PERDIDO KEY BEACH NOURISHMENT PROJECT: GULF ISLANDS September, 1993
NATIONAL SEASHORE
1992 Annual Report
7. Autbor(s) 8. Performina Orgauitation report No.
Emre N. Otay and Robert G. Dean UFL/COEL-93/005
9. PerforLing Organisatioa mwe and Address 10. Project/Task/Work DOLt No.
Coastal and Oceanographic Engineering Department
University of Florida 11. contract or Crant no.
336 Weil Hall N62467-89-C-0500
Gainesville, FL 32611
13. Type of report
12. Sponsoring Orlanizaton N ame and Address
Department of the Navy Annual Report
Southern Division
Naval Facilities Engineering Command
Charleston, SC 29411-0068 14.
15. Supplemenary Notes
16. Abscract
This report is the third annual report in a continuing series documenting a field project
within the Gulf Islands National Seashore at Perdido Key, Florida. The field project includes
the monitoring of a number of physical parameters related to the evolution of the Perdido Key
beach nourishment project. Approximately 4.1 million m3 of dredge spoil from Pensacola Pass
were placed upon approximately 7 km of the Gulf of Mexico beaches and 3 million m3 offshore
of Perdido Key between November, 1989, and October, 1991.
Beach profile data describing the evolution of the nourished beach are included, as well
as wave, current, tide, wind, temperature, and rainfall data to describe the forces influencing
the evolution. Data describing the sediment sizes throughout the project area are also included.
A brief discussion of the data is included with an emphasis on evolution of the beach and
offshore nourishment.
17. Otginator's Key uords 18. Availability Stament
Beach nourishment
Sediment transport
Shoreline response
19. U. S. Security Ciassti. of the Report 20. U. S. Security Claesai. of This Page 21. No. of pages 22. Price
Unclassified Unclassified 238
UFL/COEL-93-005
PERDIDO KEY BEACH NOURISHMENT PROJECT:
GULF ISLANDS NATIONAL SEASHORE
1992 Annual Report
Submitted to:
Department of the Navy
Southern Division
Naval Facilities Engineering Command
Charleston, SC 29411-0068
Prepared by:
Emre N. Otay
Robert G. Dean
Coastal and Oceanographic Engineering Department
University of Florida
Gainesville, FL 32611
September, 1993
TABLE OF CONTENTS
LIST OF FIGURES iv
LIST OF TABLES vi
1 INTRODUCTION 1
2 DATA COLLECTION 1
2.1 Hydrographic and Topographic Surveys ...................................... .......... 6
2.2 Wave/Current/Tide Data ......................................................................... 6
2.3 Sand Samples ........................................................................................... 7
2.4 W weather Data ............................................................... ............................ 8
2.5 Photographic Documentation ................................................................... 8
3 ISSUES CURRENTLY UNDER INVESTIGATION 8
3.1 Nearshore Berm Evolution .......................................................................... 9
3.2 Wave Data Comparison .......................................................................... 14
3.3 Washover Deposits Due to Hurricane Andrew ........................................ 17
4 DISCUSSION 17
4.1 Concentration of Fines ........................................................................... 17
4.2 Sediment Characteristics ....................................................................... 21
4.3 Profile Equilibration and Cross- Shore Sediment Transport ................... 21
5 REFERENCES
APPENDIX I: BEACH and OFFSHORE PROFILES
APPENDIX II: WAVE, CURRENT, and TIDE DATA
January, 1992 December, 1992
APPENDIX III: GRAIN SIZE DISTRIBUTIONS
APPENDIX IV: METEOROLOGICAL DATA
January, 1992 December, 1992
I-i
'I-i
Ill-i
'V-i
LIST OF FIGURES
FIGURE PAGE
1 Site location chart ............................................. .................... 2
2 Components of beach nourishment monitoring project ................. 3
3 Cross-section of the profile nourishment at R-50 ........................ 10
4 Cross-section of the profile nourishment at R-58 ........................ 11
5 Three-dimensional view of the profile nourished area as measured
in October, 1992 ................................................. .................... 12
6 Contour map of the profile nourished area as measured in October,
1992 .......................................................... ............................. 13
7 Representative wave period (T ), significant wave height (HA ) and
tidal stage recorded at Ranger Station during Hurricane Andrew .... 15
8 Representative wave period (Tm ), significant wave height (H,) and
tidal stage recorded at Caucus Shoal during Hurricane Andrew ...... 16
9 Profiles at R-54 before and after Hurricane Andrew, showing
shoreline recession and overwash................................... ......... 18
10 Percentage of fines for 5 m samples for all years of study............... 19
11 Percentage of fines for 8 m samples for all years of study............... 20
12a,b Longshore distribution of D,0 for October, 1992 (solid line) with
envelope (dashed line) of sizes for 1989, 1990, 1991 and 1992 ...... 22,23
FIGURE PAGE
13 Cross-shore distribution of D,0. Temporal variation for all years of
study .......................................................... ............................ 24
14 Evolution of dry beach width since completion of beach
nourishm ent ......................................................... ........................ 25
15 Movement of-4 m contour since completion of beach nourishment 26
16 Average of profiles within nourished area. Averages based on
profiles at R-45, R-46, R-48, R-50, R-52, R-54, R-56 and R-58 ..... 28
17 Average of profiles west of nourished area. Averages based on
profiles at R-30, R-32, R-34, R-36 and R-38 ................................ 29
18 Cross-shore sediment transport within nourished area .................... 30
19 Cross-shore sediment transport west of nourished area ................... 31
LIST OF TABLES
PAGE
Chronology of Perdido Key field efforts .................................
Chronology of Perdido Key field efforts (cont'd) .......................
TABLE
1
1
DRAFT
PERDIDO KEY BEACH NOURISHMENT PROJECT:
GULF ISLANDS NATIONAL SEASHORE
1992 ANNUAL REPORT
1 INTRODUCTION
This report is one in a series of annual summaries of a continuing field project within
Gulf Islands National Seashore at Perdido Key, Florida (Figure 1). Between November 1989 and
September 1990 approximately 4.1 million m3 of dredge material were placed along the eastern 7
km of the Gulf of Mexico shoreline of Perdido Key. From September 1990 to October 1991, an
additional approximately 3 million m3 of material were placed as an underwater deposit between
DNR Monuments R-48 and R-60, extending 3.8 km in the longshore direction and up to 700 m
in the cross-shore direction (see Figure 2).
Earlier reports (Work et al. 1990a, 1990b, 1991a, 1991b, 1991c, 1992a) discussed the
site and physical data collection methods in detail. The focus of this report will be the results of
the field work and physical data collection for 1992. The data describe topographic and
bathymetric changes of the area, waves, currents, tides, sediment sizes, winds, temperatures and
rainfall.
2 DATA COLLECTION
The study area and the data collection sites are shown in Figure 2. Table 1 presents a
chronological summary of the ongoing field efforts since commencement of the project. A
discussion of the data collection and analysis methods can be found in previous reports; only a
brief summary will be included here.
I ^O-
C,
0A
Figure 1: Site location chart
I
?I
0 Z
LU
IO
L I
0
rr
,i
z
-J
Figure 2: Components of beach nourishment monitoring project
Table 1: Chronology of Perdido Key field efforts
Date
10/28-11/1/89
11/17/89
1/18/90
1/29/90
1/30/90
3/7-3/9/90
5/2/99
6/24/90
8/8/90
8/17/90
9/22-9/26/90
12/6/90
1/29-2/3/91
5/15-5/16/91
5/28-6/1/91
6/18-6/19/91
7/29-7/30/91
9/10/91
9/28-10/2/91
10/12-10/20/91
Task
Pre-nourishment survey:
Wading/swimming profiles (Gulf and Bay) Offshore bathymetry
Sand samples, photos
Placement of nourishment material begins
Wave gage tripod and standalone gage installed
Tide gage with small stilling well installed at Ft. Pickens Pier, Santa Rosa Island
Mechanical (analog) weather station installed
Large stilling well installed for Ft. Pickens tide gage
56 sand samples collected, to replace those destroyed or not collected during
pre-nourishment survey
Standalone wave data collection package replaced with new package
Digital weather station installed
Standalone wave data collection package replaced with new package
Placement of nourishment material completed
First post-nourishment survey:
Wading/swimming profiles (Gulf side)
Offshore bathymetry
Sand samples, photos
Standalone wave data collection package replaced with new package
Ft. Pickens pier tide gage re-surveyed
Wading/swimming profile survey (Gulf side)
Sand samples
Wave gage cable re-buried
Wading/swimming profile survey (Gulf side)
Sand samples
Shore-connected wave gage removed; cable cut
Standalone wave gage installed
Wind vane and anemometer replaced
Standalone wave gage removed
Fresh standalone wave gage installed
Wading/swimming profile survey (Gulf side)
Sand samples, photos
Reattached Ft. Pickens pier tide gage
yearly survey:
Wading/swimming profiles (Gulf side)
Offshore bathymetry
Installed heavyweight data/power cable for wave gage
Replaced standalone wave gage near Ranger Station
Installed shore-connected wave gage near Ranger Station
Sand samples, photos
Table 1: Chronology of Perdido Key field efforts (cont'd)
Date ITask
10/23-10/24/91
1/16-1/22/92
4/15-4/16/92
7/8/92
10/17-10/20/92
10/27-10/29/92
1/22-1/25/93
5/14-5/18/93
Replaced shore-connected wave gage near Ranger Station
Wading/swimming profiles (Gulf side)
Replaced wind vane/anemometer
Replaced shore-connected wave gage near Ranger Station
Replaced standalone wave gage near Ranger Station
Replaced shore-connected wave gage near Ranger Station
Removed standalone wave gage from Ranger Station
Installed new standalone wave gage near Caucus Shoal
Replaced shore-connected wave gage near Ranger Station
Replaced standalone wave gage near Caucus Shoal
yearly survey:
Wading/swimming profiles (Gulf side)
Replaced shore-connected wave gage near Ranger Station
Replaced standalone wave gage near Caucus Shoal
Sand samples, photos
Replaced weather station
bathymetric survey of range lines (Gulf side)
bathymetric survey of"Profile Nourishment"
Wading/swimming profiles (Gulf side)
Cleaned shore-connected wave gage near Ranger Station
Replaced standalone wave gage near Caucus Shoal
Reset weather station
Wading/swimming profiles (Gulf side)
Bathymetric survey of 8 lines along "Profile Nourishment"
Bathymetric survey of"Profile Nourishment"
Wading/swimming surveys of beach cusps
Cleaned shore-connected wave gage near Ranger Station
Replaced standalone wave gage near Caucus Shoal
Reset weather station
2.1 Hydrographic and Topographic Surveys
The survey equipment and methodology used were unchanged from previous surveys.
The beach profiles were surveyed to approximate depths of 4 to 5 m employing standard
rod-and-level techniques, by first wading and then swimming over the deeper portions of the
profiles. The offshore profile was surveyed by a boat equipped with a fathometer to measure
depths and a microwave rangefinder system to measure horizontal distances. The profile lines
were surveyed using the same azimuth values as in the previous surveys.
During the annual survey in October, 1992 twenty-five profiles were surveyed by boat,
and an additional eight have been surveyed to wading/swimming depth (generally 4-5 m) only, in
order to improve spatial resolution of the evolution of the beach nourishment. A total of eleven
surveys have been conducted to date: the annual bathymetric surveys of 11/89, 9/90, 10/91 and
10/92 and the additional wading/swimming surveys of 1/91, 5/91, 9/91, 1/92, 6/92, 1/93 and
5/93. Data from the four annual surveys are presented in Appendix I.
2.2 Wave/Current/Tide Data
Waves, currents and tides are measured at two stations, one located offshore from the
Ranger Station near DNR Monument R-34, and the other on Caucus Shoal near R-62. Both
stations comprise P-U-V type electronic gages mounted on tetrapod shaped steel frames placed
on the ocean floor. The P-U-V gages consist of two electronic sensors; a pressure transducer and
a electromagnetic current meter. Raw data include a pressure signal and two velocity signals
measured on a horizontal plane perpendicular to each other. All signals are collected once every 6
hours at 1 Hz sampling frequency for a 17 minute duration.
The gage near the Ranger Station is connected by a cable to a shore station which serves
as a link for the remote control operation. The P-U-V data from this gage can be retrieved from
the University of Florida via telephone. The gage near Caucus Shoal carries a self contained
storage device which can store data until divers retrieve the package every 3-4 months.
Additional information about wave packages can be found in previous reports by Work et al.,
1990 and 1991.
The P-U-V data are analyzed using directional spectrum methods to obtain wave height,
wave period, wave direction, tide, current velocity and current direction. The computed wave,
current and tide parameters are presented in Appendix II for the period of January to December
1992. There are seven plots per month for each gage. The first four plots present wave related
parameters. These are: Wave period, significant wave height, modal wave direction and the
spreading parameters of the wave spectrum. Wave information is followed by current and tide
variables presented in three plots which show the current velocity, mean current direction and the
tidal elevation.
2.3 Sand Samples
Sand samples are collected at eight locations along the profiles: Dune, mid-beach, berm,
beachface, -1 m, -2 m, -5 m and -8 m. Details about the sampling locations and methodology can
be found in the previous reports by Work et al., 1990 and 1991.
Grain size distributions have been determined by mechanical sieve analysis of each
sample, using a series of twelve U.S. standard sieves with mesh numbers 10, 20, 30, 40, 50, 60,
70, 80, 100, 120, 140, 160. The analysis results are presented in Appendix III. Each figure shows
grain size distributions at a particular location for different sample years. Several characteristic
parameters of the grain size statistics have been analyzed, such as D50, mean diameter, sorting
index, skewness and kurtosis. In this report only results related to D,, are presented. Other
parameters can be obtained from the authors. A further discussion on sediment characteristics and
spatial/temporal variations in grain sizes can be found in Chapter 4.
2.4 Weather Data
The electronic weather station was installed in June 1990 and collected data until May
1992. In October 1992 it was replaced with a similar unit. This new station operates with a
locally installed data acquisition unit and a storage device. The weather station can be controlled
remotely from the University of Florida and the stored data can be retrieved via telephone. The
data acquisition unit consists of electronic sensors to measure wind velocity, wind direction, air
temperature and rainfall. Data are sampled at 1 Hz frequency and the hourly mean, minimum and
maximum values are saved in the storage device. Approximately once a week an operator calls
the weather station from the University of Florida and retrieves the stored data into a computer.
Appendix IV presents the analyzed data in biweekly time series of wind velocity, wind direction,
air temperature and rainfall.
2.5 Photographic Documentation
Oblique color ground photography has been taken throughout the study to document
changes as the nourished beach evolves. Photography is conducted in conjunction with each
survey. Three photos are generally taken along each profile, viewing to the left along the beach,
perpendicular to the beach and to the right along the beach. The reader may contact the authors
regarding availability of the photographs.
3 ISSUES CURRENTLY UNDER INVESTIGATION
In addition to the information presented in the preceding sections of this report, three
problems are under active study and are discussed here only briefly.
2.4 Weather Data
The electronic weather station was installed in June 1990 and collected data until May
1992. In October 1992 it was replaced with a similar unit. This new station operates with a
locally installed data acquisition unit and a storage device. The weather station can be controlled
remotely from the University of Florida and the stored data can be retrieved via telephone. The
data acquisition unit consists of electronic sensors to measure wind velocity, wind direction, air
temperature and rainfall. Data are sampled at 1 Hz frequency and the hourly mean, minimum and
maximum values are saved in the storage device. Approximately once a week an operator calls
the weather station from the University of Florida and retrieves the stored data into a computer.
Appendix IV presents the analyzed data in biweekly time series of wind velocity, wind direction,
air temperature and rainfall.
2.5 Photographic Documentation
Oblique color ground photography has been taken throughout the study to document
changes as the nourished beach evolves. Photography is conducted in conjunction with each
survey. Three photos are generally taken along each profile, viewing to the left along the beach,
perpendicular to the beach and to the right along the beach. The reader may contact the authors
regarding availability of the photographs.
3 ISSUES CURRENTLY UNDER INVESTIGATION
In addition to the information presented in the preceding sections of this report, three
problems are under active study and are discussed here only briefly.
3.1 Nearshore Berm Evolution
As noted, following the beach nourishment, approximately 3 million cubic meters of
sand were placed underwater in the area shown in Figure 2. Figures 3 and 4 show cross-sections
through the entire profiles including the profile nourishment area for DNR Monuments R-50 and
R-58. This portion of the nourishment is referred to as "profile nourishment" as distinguished
from the "beach" nourishment which advanced the dry beach and its underwater extension. The
profile nourishment sand was placed by bottom-dump barges such that each placement results in
a more or less identifiable mound with the entire placement appearing as a very "hummocky"
terrain (see Figure 5). Although the original program did not call for study of this portion of the
nourishment, the program scope was modified in Spring, 1992 to include this element. Starting
with the Fall survey of 1992, our annual surveys have encompassed the profile nourishment area.
These efforts have included an extension of the profile lines in the area of profile nourishment
and additional surveys "blanketing" the area. The results from the bathymetric survey in October,
1992 are presented in Figures 5 and 6 which show a three-dimensional view and a contour map
of the nourished area.
The major issues concerning the profile nourishment center around the movement of the
sand ashore with special emphasis on the rate. The rationale for hypothesizing landward
movement is that if the profile was initially in equilibrium and "active", placement of additional
material such as occurred here will result in a profile with an "excess of sand" leading to onshore
sediment transport. Methods currently being employed to address this question include a focus
on the landward edge of the placed material and the bathymetric evolution with particular
emphasis on smoothing of the surface features. Perdido Key was impacted by Hurricane Andrew
in October 1992 with peak significant waves at the two gages measured at 2.7 m. Based upon
analysis of the profile nourishment data, it appears that there may be a small net landward
Perdido Key: Range 50 Azimuth 165 degrees
0 i
0
-44
- -4 ,
0 200 400 600 800 1000 1200 1400 1600
Distance from Monument [m]
Figure 3: Cross-section of the profile nourishment at R-50.
Perdido Key: Range 58 Azimuth 165 degrees
0 200 400 600 800 1000 1200 1400 1600
Distance from Monument [m]
Figure 4: Cross-section of the profile nourishment at R-58.
Perd do Key Ne rshore Nour Lshmen
Figure 5: Three-dimensional view of the profile nourished area as measured in October, 1992.
Figure 5: Three-dimensional view of the profile nourished area as measured in October, 1992.
t
CSk
I I
!
Perdido Key Nearshore Nourishment
400 600 800 1000 1200 1400 1600
5000 5000
5000 4 500
0 9-
C -6.0
4000 o 4000
3500 3500
E 3000 ,= 3000
o
5 2500 7. 2500
0
S2000 2000
S70-7.0
1500 1500
S -- ---7.5
1000 O --- 1000
500 500
R-60 0
400 600 800 1000 1200 1400 1600
Cross-Shore Distance m
Figure 6: Contour map of the profile nourished area as measured in October, 1992.
13
movement of the underwater berm forming the profile nourishment; however, most of the
evolution is apparent as a "spreading out" of the placed material. This is evident in Figures 3 and
4 for Monuments R-50 and R-58.
In addition to continuing to monitor the profile placement geometry, future efforts will
be directed to the development of methodology for the prediction of the evolution of the
underwater mound, including the rate of landward migration and the smoothing of the surface
features.
3.2 Wave Data Comparison
As discussed previously, a second wave gage was installed in the vicinity of Caucus
Shoals in April, 1992. One purpose of this gage was to identify and document any localized
effects of the Entrance to Pensacola Bay, including the effects of Caucus Shoals. It is expected
that causes of different wave properties at the two sites could include both wave refraction and
wave diffraction, each of which can modify the wave height and wave direction. The effects of
these processes are important as they can cause localized changes in the longshore sediment
transport over the length of the nourishment project. These wave transformation phenomena are
complicated due to the fact that they are functions of the incident wave direction and wave
period. Also wave gages have a tendency to malfunction. The pressure sensor which provides the
basis for determining wave heights is the most reliable element of the gage and the current meter
which provides the basis for establishing wave direction is the least reliable.
At present, efforts are underway to identify portions of the wave records which are
well-suited for identifying the wave transformation effects. Figures 7 and 8 present the wave
characteristics at the two gages during the passage of Hurricane Andrew where it can be seen that
the wave heights were approximately the same, at least until the Caucus Shoals gage ceased to
I
PERDIDO KEY: RANGER STATION
20
15
Tn 10
(SEC)
5
0
4
3
1 5 10 15 20 25 30
1 5 10 15 20 25 30
1 5
15
AUG.,1992
Figure 7: Representative wave period (Tm), significant wave height (H) and tidal stage recorded
at Ranger Station during Hurricane Andrew.
I 1 1 1 1 1 1 1 1 1 I I I I I I I II I I II II I
PEROIDO KEY: CAUCUS SHOAL
20
15
Tm 10
(SEC)
5
0
1 5 10 15 20 25
1 5 10 15 20 25 30
AUG.. 1992
Figure 8: Representative wave period (Tm), significant wave height (H,) and tidal stage recorded
at Caucus Shoal during Hurricane Andrew.
Tinnnnl l i i n n *i i i i ^ i i i i i
function near the period of highest waves at about noon on August 24, 1992. During this period,
the wave direction was not well established at either gage.
3.3 Washover Deposits Due to Hurricane Andrew
Hurricane Andrew caused washover deposits along portions of Perdido Key. These
deposits can be characterized as extending approximately 25 m inland from the seaward limit of
the berm and with a thickness of approximately 50 cm. Figure 9 presents an example of a
cross-section (R-54) through the profile showing the washover deposit This deposit of sand has
had the intended purpose of allowing the beach berm to build up naturally rather than to prevent
overwash as would occur if the constructed berm were high as was the case for the 1985 beach
nourishment. A very strong recovery "ridge" is also present in Figure 9. A manuscript is being
developed for journal publication consideration describing this washover event and evaluating
various methods for predicting the washover process and magnitudes.
4 DISCUSSION
Several features of the monitoring program, based on data collected last year merit
discussion as presented below.
4.1 Concentration of Fines
The concentration of fines, located primarily between Ranges R-42 and R-59, are shown
in Figures 10 and 11 respectively for the 5 and 8 m contours, and appear to be decreasing with
time. The origin of these fines is the Pleistocene mud deposits that were excavated in the
dredging operation. The decrease of fines with time is to be expected due to suspension during
energetic wave events which causes suspension of the fines and distribution over wide areas.
I
Perdido Key Profiles
190 200 210 220 230 240 250
Distance from Monument [m]
260 270 280
Figure 9: Profiles at R-54 before and after Hurricane Andrew, showing shoreline recession and
overwash.
-0.5
-1 -
180
5 m Sand Samples
F
percentagee Finer than 0.0097 mm
I I '
I ii
; it II
;i '
i I
; :; M i -
i
i; !\ i '* i l \
i' V.
S i ''. i i 'i
1t ; I ; 1
it \ \ ^ \ i !. i
I / I \
: \ .i I
._ ., I, ?. ... i_ -
-...............- Nov.'89
------------. Sep.'90
---- Oct.'91
-- Oct.'92
-4
35 40 45 50 55 60 65
Range Number
Figure 10: Percentage of fines for 5 m samples for all years of study.
20
10
0
30
~ -`
8 m Sand Samples
Percentage Finer than 0.0097 mm
I I 1 1 I I I I
:ii
................ .'
Nov.'89
| ------ Sep.'90
------- Oct.'91
Oct.'92
40 1-
20 1-
i I I--i-
30 35 40 45 50
Range Number
55 60 65 70
Figure 11: Percentage of fines for 8 m samples for all years of study.
80 -
60 -
I . .
t
However the interpretation of the suspension and transport of fines must be tempered with the
understanding that the distribution can be somewhat "spotty" due to local depressions and thus
the data must be interpreted in the "aggregate" sense rather than on the basis of individual
samples.
4.2 Sediment Characteristics
Sediment characteristics are summarized in Figure 12a for the dune, mid-beach, berm
and beach face locations and in Figure 12b for the Im, 2m, 5m and 8m depths. The solid line in
each of these figures represents the October, 1992 median diameters and the dotted lines
represent the envelope of the size distributions measured including pre-nourishment. It is seen
that in general the 1992 sizes are nearer the lower limit of the envelope than the upper limit. This
is also shown in Figure 13 which shows the temporal variation of the longshore averaged median
values. There is a discernible but slight trend toward the smaller sizes. The reason for this is not
known as many times it is found that new deposits will experience "natural armoring" in which
the finer sand will be removed by wind or water action leaving the less erodible coarser material.
It is possible that Hurricane Andrew contributed to this effect. The two planned future sediment
collections and analysis efforts may provide a basis for further interpretation and understanding.
4.3 Profile Equilibration and Cross-Shore Sediment Transport
The profiles in the nourishment project were placed steeper than those present prior to
the nourishment project. Because the nourishment sediment is compatible to the native, it is
expected that the final equilibrated profile will be very similar to the original. This equilibration
is evident from Figures 14 and 15 which present respectively the alongshore changes in the dry
beach width since November, 1989 and the alongshore change in the position of the 4 m contour
Mid Beach
0.6
E0.4
E
0.2
"0.2
Berm
40 50
Range Number
40 50
Range Number
Beach Face
40 50
Range Number
Figure 12a: Longshore distribution of D50 for October, 1992 (solid line) with envelope
(dashed lines) of sizes for 1989, 1990, 1991 and 1992.
'N?
Dune
-1 m
A /,A
,/ -
/ '\ ...... / ."
"' /" .,
40 50
Range Number
-5 m
40 50
Range Number
40 50
Range Number
Figure 12b: Longshore distribution of D50 for October, 1992 (solid line) with envelope
(dashed lines) of sizes for 1989, 1990, 1991 and 1992.
0.6
-O.4
E
0
00.2
0
3
-2 m
-8 m
0
Crosshore Distribution of D50
Longshore averaged for All Years
0.6
E
E
( 0.4
N
C)
S-,
W 0.2
E
U)
-c3
mid-beach beachface -2 m -8 m
*Nov.1989 ESep.1990 *Oct.1991 EIOct.1992
Figure 13: Cross-shore distribution of D50. Temporal variation for all years of study.
function near the period of highest waves at about noon on August 24, 1992. During this period,
the wave direction was not well established at either gage.
3.3 Washover Deposits Due to Hurricane Andrew
Hurricane Andrew caused washover deposits along portions of Perdido Key. These
deposits can be characterized as extending approximately 25 m inland from the seaward limit of
the berm and with a thickness of approximately 50 cm. Figure 9 presents an example of a
cross-section (R-54) through the profile showing the washover deposit This deposit of sand has
had the intended purpose of allowing the beach berm to build up naturally rather than to prevent
overwash as would occur if the constructed berm were high as was the case for the 1985 beach
nourishment. A very strong recovery "ridge" is also present in Figure 9. A manuscript is being
developed for journal publication consideration describing this washover event and evaluating
various methods for predicting the washover process and magnitudes.
4 DISCUSSION
Several features of the monitoring program, based on data collected last year merit
discussion as presented below.
4.1 Concentration of Fines
The concentration of fines, located primarily between Ranges R-42 and R-59, are shown
in Figures 10 and 11 respectively for the 5 and 8 m contours, and appear to be decreasing with
time. The origin of these fines is the Pleistocene mud deposits that were excavated in the
dredging operation. The decrease of fines with time is to be expected due to suspension during
energetic wave events which causes suspension of the fines and distribution over wide areas.
I
Perdido Key Beach Nourishment
Planform Evolution
200
so
0
z
~100
50
C
0)
0
30 35 40 45 50 55 60 65
Range Number
Figure 14: Evolution of dry beach width since completion of beach nourishment.
50
0
-50
-100
30
Perdido Key Beach Nourishment
Movement of -4 m Contour
35 40 45 50 55 60 65
Range Number
Figure 15: Movement of-4 m contour since completion of beach nourishment.
since November, 1989. The post nourishment recession of the dry beach and advancement of the
4 m contour within the nourishment area are indications of a reduction in profile slope. This
slope equilibration is also evident in Figure 16 which presents the average of eight profiles
within the nourishment area. The upper portions of the profiles (down to an elevation of
approximately -0.6 m) appear to have always had approximately the same slope as prior to
nourishment. This could be due to very rapid adjustment before the first post-nourishment survey
or could be due to the placement slope coinciding with the equilibrium slope. It is likely that
both explanations are correct to some degree. Proceeding to greater depths, the offshore bar is not
as well developed as for the pre-nourishment profiles. In fact the average profile one year after
nourishment has only a small indication of a bar whereas after two years, the bar is now better
developed. The slopes seaward of the bar are still substantially steeper than the pre-nourishment
values. The features discussed above are consistent with the fact that the upper portions of the
water column experience more wave energy and thus equilibrate more rapidly than the lower
portions. Profile equilibration was hastened by the maximum 2.7 m peak significant wave
heights (Figures 7 and 8) which occurred during Hurricane Andrew. However waves of this
height had occurred previously at least twice during this study. It is generally believed, based on
very limited data, that cross-shore equilibration requires approximately 2 to 5 years. Although the
data collected in conjunction with this study seem reasonably consistent with this time frame,
they provide more detail in particular the progressive evolution toward equilibrium with
increasing water depth. Finally, it should be noted that these profile equilibration data provide
the best documentation for any beach nourishment project to date. Figure 17 presents, for
comparison the average of five profiles west of the nourishment.
An estimate of the average cross-shore sediment transport can be determined from
sequential average profiles as presented in Figures 16 and 17. These calculated cross-shore
transport rates which are presented in Figures 18 and 19 do not account for sand removed by
I
Average Profiles Within Nourished Area
o -
> "
CU
-300 -200 -100 0 100 200
Distance from Sep.90 Waterline [m]
>\ .
R-45, R-46, R-48, R-50, R-52, R-54, R-56 and R-58.
-6-
-300 -200 -100 0 100 200
Distance from Sep.90 Waterline [m]
Figure 16: Average of profiles within nourished area. Averages based on profiles at
R-45, R-46, R-48, R-50, R-52, R-54, R-56 and R-58.
I
Average Profiles West of Nourished Area
-50 0 50 100 150 200 250
Distance from Sep.90 Waterline [m]
300 350 400
Figure 17: Average of profiles west of nourished area. Averages based on profiles at
R-30, R-32, R-34, R-36 and R-38.
0.20
0.15 k
Cross-shore Transport Rate within Nourished Area
-......... Sep.'90 Oct.'91
\ ---------- Sep.'90 Oct.'92
S-- ct.'91 Oct.'92
0.05 -
0.00 -
-200
-100 0 100 200
Distance from Sep.'90 Waterline [m]
Figure 18: Cross-shore sediment transport within nourished area, based on average
profiles shown in Figure 16. Results based on profile deformations occurring between
September, 1990 and October, 1992.
V
ca
-0
Ci
cr
Cross-shore Transport Rate West of Nourished Area
0.10
0.08 -
0.06 -
Sep.'90 Oct.'91
0.04 -- -- --- Sep.'90 Oct.'92
SOct.'91 Oct.'92
o.o2 -
0.00 .... .............
-0.02
-0.04 -
-0.06
-0.08 I- -I-,-I -- I I
-100 0 100 200 300 400
Distance from Sep.'90 Waterline [m]
Figure 19: Cross-shore sediment transport west of nourished area, based on average
profiles shown in Figure 17. Results based on profile deformations occurring between
September, 1990 and October, 1992.
longshore transport. It is seen that within the nourished area (Figure 18), the maximum
cross-shore transport during the second year after nourishment is approximately 60% to 70% of
the value during the first year, even with the mobilizing activity of Hurricane Andrew during the
second year. The approximate cross-shore sediment transport for the profiles west of the
nourishment project is shown in Figure 19. Without discussing the details, the peak offshore
transport magnitudes within the nourishment area are approximately 2.5 times greater than the
transport magnitudes west of the nourishment area.
4 REFERENCES
Work, P.A., Lin, L.-H., and Dean, R.G., 1990a. "Perdido Key Beach Nourishment Project: Gulf
Islands National Seashore. Pre- Nourishment Survey, Conducted October 28 November
1989." Coastal and Oceanographic Engineering Department, University of Florida,
Gainesville, Florida. April 30, 1990. COEL 90/006.
Work, P.A., Lin, L.-H., and Dean, R.G., 1990b. "Perdido Key Beach Nourishment Project: Gulf
Islands National Seashore. First Progress Report." Coastal and Oceanographic
Engineering Department, University of Florida, Gainesville, Florida. August 27, 1990.
COEL 90/009.
Work, P.A., Lin, L.-H., and Dean, R.G., 1991a. "Perdido Key Beach Nourishment Project: Gulf
Islands National Seashore. First Post- Nourishment Survey Conducted September
22-26, 1990." Coastal and Oceanographic Engineering Department, University of
Florida, Gainesville, Florida. January, 1991. COEL 91/003.
Work, P.A., Lin, L.-H., and Dean, R.G., 1991b. "Perdido Key Beach Nourishment Project: Gulf
Islands National Seashore. 1990 Annual Report." Coastal and Oceanographic
Engineering Department, University of Florida, Gainesville, Florida. January, 1991.
COEL 91/004.
Work, P.A., Charles, L., and Dean, R.G., 1991c. "Perdido Key Beach Historical Summary and
Interpretation of Monitoring Programs.." Coastal and Oceanographic Engineering
Department, University of Florida, Gainesville, Florida. January, 1991. COEL 91/009.
Work, P.A., and Dean, R.G., 1992a. "Perdido Key Beach Nourishment Project: Gulf Islands
National Seashore. 1991 Annual Report." Coastal and Oceanographic Engineering
Department, University of Florida, Gainesville, Florida. July, 1992. COEL 92/012.
Work, P.A., 1992b. "Sediment Transport Processes at a Nourished Beach." Ph.D. Dissertation,
Coastal and Oceanographic Engineering Department, University of Florida, Gainesville,
Florida. December, 1992. COEL TR/087.
APPENDIX I
BEACH and OFFSHORE PROFILES
Notes: 1) All elevations are in meters, relative to NGVD.
2) Horizontal origin is the survey monument, with distances toward
the Gulf of Mexico defined as positive.
3) Reported bearings are for observer standing on monument,
looking offshore along survey line.
Perdido Key: Range 30 Azimuth 170 degrees
400
600
800
Distance from Monument [m]
200
1000
Range 32 Azimuth 170 degrees
0 200 400 600
800
Distance from Monument [m]
-4
-6
1000
Perdido Key:
- Azimuth 165 degrees
0 200 400 600
800
Distance from Monument [m]
-2
-4
-6
1000
Perdido Key:
Range 34
Perdido Key: Range 36 Azimuth 165 degrees
4I I I I
Nov.89
Sep.90
2 ~- i 1 Oct.91
|~ Oct.92
Q)
0
- ~
-4
-6
-20 0 I 6
-200 0 200 400 600 800
Distance from Monument [m]
- Azimuth 160 degrees
-200 0 200 400 600
800
Distance from Monument
-2
-4
1000
Perdido Key:
Range 38
[m]
- Azimuth 160 degrees
0 200 400 600
Distance from Monument [m]
-2
-4
-6
-200
800
1000
Perdido Key: Range 40
Perdido Key: Range 42 Azimuth 160 degrees
200 400 600 800
1000
Distance from Monument [m]
-2
-4
- Azimuth 160 degrees
0 200 400 600 800
Distance from Monument
0
-2
-4
1000
Perdido Key:
Range 43
[m]
Perdido Key: Range 44 Azimuth 160 degrees
4
Nov.89
Sep.90 -
2-- /ii, Oct.91
1 Oct.92
>0
I .. ..........................
-2
0
l)
S-4
-6 I
-8F
-200 0 200 400 600 800 1000
-200 0 200 400 600 800 1000
Distance from Monument [m]
- Azimuth 160 degrees
0 200 400 600 800
Distance from Monument [m]
-200
1000
Perdido Key:
Range 45
- Azimuth 165 degrees
0 500 1000
Distance from Monument [m]
-6
-8
-10
1500
Perdido Key:
Range 46
Range 48 Azimuth 165 degrees
Nov.89
Sep.90
Oct.91
Oct.92
0 500 1000
Distance from Monument [m]
0
-2
-4
1500
Perdido Key:
Perdido Key: Range 50 Azimuth 165 degrees
4 N ov.t -U
Sep.90 -
Oct.91 ---
2-
2 -, Oct.92
a i iI
i^
I \
2-
0
-) -4-
6 -.......
-8
0 200 400 600 800 1000 1200 1400 1600
0 200 400 600 800 1000 1200 1400 1600
Distance from Monument [m]
- Azimuth 165 degrees
0 500 1000
1500
Distance from Monument
0
-2
-4
-6
-8
Perdido Key:
Range 52
[m]
- Azimuth 165 degrees
4
Nov.89---
Sep.90 ----
2 Oct.91
/ n \Oct.92
0 0 --.----
o
S -
Q) -4
-6
-8
I I I I I I I I
0 200 400 600 800 1000 1200 1400 1600
Distance from Monument [m]
Perdido Key: Range 54
Perdido Key: Range 56 Azimuth 165 degrees
0
-2
-4
-6
1000 1200
1400 1600
Distance from Monument [m]
200
400
600
800
Perdido Key: Range 58 Azimuth 165 degrees
4 -
Nov.89
Sep.90
2 Oct.91 --
S i- Oct.92
0I
S\i
S -4--
....1
-6-
I I I I I I I 1 I
0 200 400 600 800 1000 1200 1400 1600
Distance from Monument [m]
- Azimuth 165 degrees
0 500 1000
1500
Distance from Monument [m]
0
-2
-4
-6
Perdido Key: Range 60
- Azimuth 165 degrees
0 500 1000
Distance from Monument [m]
1500
Range 61
Perdido Key:
Perdido Key: Range 62 Azimuth 165 degrees
200 400 600 800
1000
Distance from Monument [m]
-2
-4
- Azimuth 165 degrees
0 200 400 600 800
Distance from Monument
-3
-4
1000
Perdido Key:
Range 63
[m]
Perdido Key: Range 64 Azimuth 170 degrees
0 200 400 600 800
Distance from Monument [m]
-1
-2
-3
-4
1000
Perdido Key: Range 65 Azimuth 105 degrees
0 200 400 600 800
Distance from Monument [m]
-5
-10
-15
1000
- Azimuth 105 degrees
0 200 400 600 800
Distance from Monument
-5
-10
-15
1000
Perdido Key:
Range 66
[m]
- Azimuth 90 degrees
400 600 800
1000
Distance from Monument
-5
-10
-15
-20
200
Perdido Key:
Range 67
[m]
APPENDIX I
WAVE, CURRENT, and TIDE DATA
from Offshore Gages
located near Ranger Station and near Caucus Shoal
January, 1992 December, 1992
Representative Wave Period
Significant Wave Height
Central Wave Direction
Spreading Parameters
Mean Current Velocity
Mean Current Direction
Tidal Stage
Notes: 1) Mean wave direction, G, is the direction that the wave is
heading. It is measured clockwise from magnetic north.
2) Mean current direction, 09, is the direction toward which the
current is heading. It is measured clockwise from magnetic
north.
3) Horizontal axis denotes day of month.
4) Tidal datum is mean sea level.
20
15
Tm 10
(SEC)
5
0
3
3
90 -
60 -
30 -
PERDIDO KEY: RANGER STATION
-
1 5 10 15 20 25 29
1 5 10 15 20 25 29
+ + + ++ +- 4
S+ + ++ + +++ + +
+ + -+ c+c'+
+ ++
+ +
1 4 + 1 + + + + +
+ +++ +
+ + ++ +
S+ + ++
S+ + + + +
+ +
I +4- I I4 I I I I I II4:1 1 1 1 1 1 1 I 1 1 1 1 I I
1 5 10 15 20 25 29
Si:+ S2:~
5
25 29
JAN.,1992
Figure II-i: Representative Wave Period, Significant Wave Height, Central
Direction and Spreading Parameters, January, 1992.
11-2
I I I I I ~LA- I
I lmm .'.lIII r'fUl1 ..I. I TTTI'f.~ l.."nr ;'. ,,, n ,,,'=.rrI I I
II
L I
PERDIDO KEY: RANGER STATION
1.0
0.8 -
Uc 0.6 -
(H/S)
0. -
0.2 +
o .................................................0 iio. ii +
1 5 10 15 20 25 29
i 1
9c
(DEG)
++ +
+ +
,1 5 10 Isll1I 20 25 29,
1 5 10 15 20 25 29
(M) 0
-1
-2
1 5 10 15 20 25 29
JAN. ,1992
Figure 11-2: Magnitude and Direction of Mean Current and Tidal Stage,
January, 1992.
II-3
--I
PERDIDO KEY: RANGER STATION
20
15 -
Tt 10 -
(SEC)
5
1 5 10 15 20 25 29
3
Hs 2
(M)
0 A
1 5 10 15 20 25 29
+
N +' "'+ + +' +
8 E
S
S I I I I I I I I I I I I I I I I I I I I I I I I I
1 5 10 15 20 25 29
120
Si:+ Sa2:
90
e +
S 60 Q O o o
300 00 0 0
030 -,1 + 44 o -
+ + + + *F 0
0 1 ,1t 4^ 1 1W 1 1 L + I +
1 5 10 15 20 25 29
FEB. 1992
Figure 11-3: Representative Wave Period, Significant Wave Height, Central
Direction and Spreading Parameters, February, 1992.
1-4
PERDIDO KEY: RANGER STATION
0.8 k
Uc 0.6
(M/S)
0.4 -
0.2
+ + +F +15 20
1 5 10 15 20 25 29
w -
+ ++ ++
+ +++
+~ f ~i'4 +44+ +
+e
+++ +
+ + + + +
++ +
+ +- +++
+++ + ,++
+ + ++ +%
++
W I I I + 1 I I I I I I I I I I I I I I I I
1 5 10 15 20 25 29
2
1
TIDE
(M) 0 -
-1
2 I I I I I I I I I I I I I I I I I I I I I I I I I II
1 5 10 15 20 25 29
FEB., 1992
Figure 11-4: Magnitude and Direction of Mean Current and Tidal Stage,
February, 1992.
11-5
8c
(DEG)
PERDIDO KEY: RANGER STATION
20
15
Tm 10
(SEC)
5
0
1
0
W
N
9 E
S
W
120
90
S 60
30
0
1 5 10 15 20 25
1 5 10 15 20 25 30
MAR. 1992
Figure 11-5: Representative Wave Period, Significant Wave Height, Central
Direction and Spreading Parameters, March, 1992.
II-6
I I I I I I I I I I I I I I I
PERDIDO KEY: RANGER STATION
0. 8 -
Uc 0.6
(M/S)
0.4
0.2
0.0
N
ec
(DEG)
'1 5I I0 5II 20 25 30
1 5 10 15 20 25 30
1 5 10 15 20 25 30
MAR.,1992
Figure 11-6: Magnitude and Direction of Mean Current and Tidal Stage,
March, 1992.
i 11-7
t~W C~Ft~t~it~~+ktC~HIHC4.tt
+ ^+-H+.,.,.- ++. + + -T 4+ +. .,-H-
+ +
I I I
+ 1 1 1
I II I I I I I I I I I I I I I J I I I I I I
i
,
a
PERDIDO KEY: RANGER STATION
20
15
Tm 10
(SEC)
5
0
3
3
N
9 E
S
120
90
S 60
30
0
1 5 10 15 20 25 30
H ++:R + + + + +
.-.+
+ .*+,+--+ ++ + ,++
-+ ++
+ ++
+ +
+ ++++ + + +
O H + ++ +
e e SO:+ Sa:o
++ +
+
+ + Il
+
APR.,1992
Figure 11-7: Representative Wave Period, Significant Wave Height, Central
Direction and Spreading Parameters, April, 1992.
11-8
I I~ 7.2 I~ I IIIIIIIIIi I
PERDIDO KEY: RANGER STATION
1.0
0.8
Uc 0.6
(M/S)
0.4
0.2
0.0
N
8c
(DEG)
1 5 10 15 20 25 30
++ +
+,+ H + +
a +
+
I I I I I I I I I I I I I I I I I I I I I I I I I I
1 5 10 15 20 25 30
1 5 10 15 20 25 30
APR. ,1992
Figure 11-8: Magnitude and Direction of Mean Current and Tidal Stage,
April, 1992.
11-9
+
+Ht**t*M+ttHRt F.^^ *M, -AWhWwM11 II"M".
PERDIDO KEY: RANGER STATION
20
15
Tm 10
(SEC)
5
0
3
9
S 6
1 5 10 15 20 25 30
1 5 10 15 20 25 30
+ ++ ++ ++
+ + +.+ +. +++ + ++ ++
++++.- + + + + + +
+ + ++ + + +
++ + +
S+ +
0+ + ++ +
--+ +~ ++
+ I I I "+ I I I I ++ + I I
0
0 -- 5 --0 1 -0 25 30
Si:+ S2:o
0 o o
0 5 1 i 2 2 0
15 0 15 20 25 30
MRY, 1992
Figure 11-9: Representative Wave Period, Significant Wave Height, Central
Direction and Spreading Parameters, May, 1992.
II-10
PERDIDO KEY: RANGER STATION
0.8 p
Uc 0.6
(M/S)
O.U, C
0.2
0.0'
N
Be
(DEG)
1
TIDE
(M)
0 -
-1
-2
i I .i II i i -i i i ,.I= I . .
1 5 10 15 20 25 30
+ +
+ -~++ ++"
+ + ++ +- ++4
+ + 1+ +
+ + ++
+ .-Wt. 4- .+- -1.4 +-FN+ 4.+H- + ++ -+4-H- + ++
1 5 10 15 20 25 30
MAY, 1992
Figure II-10: Magnitude and Direction of Mean Current and Tidal Stage,
May, 1992.
II-11
-- + + +
,*Ctl~iHCr;h: ,1 iq i
I I I I I I I I I I I I I I I I I I I I I I I I I I
PERDIDO KEY: RANGER STATION
20
15
T" 10
(SEC)
5
0
1 5 10 15 20 25 30
90
60
15 10 15 20 25 30
.- F-+ --. .1..+ + 4
S ++ + + +
++ + ++ + +
+ + + + ++ + + +
+ + + + +
+ + ++ + + + + +
+ + +++-
++ +
+ *+ ++: ++ ++ + +
+ + + .*,I- +
1 I I I I I 15 20 25 30 1 1 1 1 I I I I I I
5 10 s15 20 25 30
1.#
JUN.,1992
Figure II-11: Representative Wave Period, Significant Wave Height, Central
Direction and Spreading Parameters, June, 1992.
II-12
Sl:+ S2:'
0
-0 0 0
. . . . A,: .... o, ,. .
PERDIDO KEY: RANGER STATION
1.0
0.8
Uc 0.6
(M/S)
0.4
0.2
0.0
N
N
8c
(DEG)
1 5 10 15 20 25 30
-H ++++(*+ I+ I HI-I
+I+H+H+H-HH+ 4+
i I1 10 111111 I 20 25 30f+II-+ I
1 5 10 15 20 25 30
JUN.,1992
Figure 11-12: Magnitude and Direction of Mean Current and Tidal Stage,
June, 1992.
11-13
I11 1 1 11 1 1 1 I I I I I I I
PERDIDO KEY: RANGER STATION
20
15
Tm 10
(SEC)
5
0
4
3
Hs 2
1 5 10 15 20 25 30
+
+ + +++ + + +
+ ++ + 4+ ++
+ + + + ++ + ++ + +
-- + + +
"-+ + ++
+ +
S+ + + + +
+ +
1 5 10 15 20 25 30I I I I I I I I I I I I I II
1 5 10 15 20 25 30
JUL.,1992
Figure 11-13: Representative Wave Period, Significant Wave Height, Central
Direction and Spreading Parameters, July, 1992.
11-14
1 5 10 15 20 25 30
SO:+ S2:*
1 5 10 15 20 25 30
90
60
PERDIDO KEY: RANGER STATION
0.8 -
Uc 0.6
(M/S)
0.4 -
0.2 -
0.0
ec
(DEG)
1
TIDE
(H)
S0
-1
-2
1 5 10 15 20 25 30
+
+ + +
+ ++
1 5 10 15 20 25 30
JUL. ,1992
Figure 11-14: Magiitude and Direction of Mean Current and Tidal Stage,
July, 1992.
11-15
I I I I I I I I I I I I I I I I I I I I I I I I I
PERDIDO KEY: RANGER STATION
20
15
Tm 10
(SEC)
5
0
4
3
1 5 10 15 20 25 30
1 5 10 15 20 25 30
9
6
1 5 10 15 20 25 30
0
Si:+ S2:o
0
0
0
0 000 0
AUG.,1992
Figure II-15: Representative Wave Period, Significant Wave Height, Central
Direction and Spreading Parameters, August, 1992.
11-16
PERDIDO KEY: RANGER STATION
1.0
0.8
Uc 0.6
(M/S)
0.4
0.2
f.tHtt Ha~ tIIIIHHtIIIIIIIIIIIIIIIIIIIC CH44-4II-4444-++4-14I4- tIIuCI 1111111 1+C
U. U
H
N
8c E
(DEG)
S
2
I I I "I T" 1 I I I I I I I I I I I I I I I I I I I I I I I I I I
1 5 10 15 20 25 30
A ++
++
+
++
1 5 10 15 20 25 30
I I
(M)
-1
2 I I I I I I I I I I I I I I I I I I
1 5 10 15 20 25 30
AUG.,1992
Figure II-16: Magnitude and Direction of Mean Current and Tidal Stage,
August, 1992.
11-17
PERDIDO KEY: RANGER STATION
20
15
T" 10
(SEC)
5
0
4
3
Hs 2
60
30
1 5 10 15 20 25 30
1 5 10 15 20 25 30
S+ + + +
+ + +
+ ++ ++
+ ++ + + ++ +
+ + + ++
+ +
+ + + + ++
+ + + +
1 1 044 I 1 I I I + I
5 10 15 20 25 30
SO:+ S2:o
15 10 15 20 25 3C
SEP. ,1992
Figure 11-17: Representative Wave Period, Significant Wave Height, Central
Direction and Spreading Parameters, September, 1992.
11-18
PERDIDO KEY: RANGER STATION
0. 8
Uc 0.6
(M/S)
0.11 -
8B
(DEG)
I I I I I I I I I I I I I I I I I I I I I I I I I I I I |I
1 5 10 15 20 25 30
*ftt" +FW + 1 11|1 111|| | 1 4+4t4ti
1 5 10 15 20 25 30
SEP. ,1992
Figure 11-18: Magnitude and Direction of Mean Current and Tidal Stage,
September, 1992.
11-19
PERDIDO KEY: RANGER STATION
20
15
TM 10
(SEC)
5
0
4
3
1
0
N
8 E
S
W
120
90
S 60
1 5 10 15 20 25 30
^++++++ + +-^ ++ +
+ + +++
+ + +
+ + + ++ + ++ +-,
+ +
+ + +
+++
S + + + +
+++ ++ +
SI + I- 1+ 1 I I I I -H I I I I I I I I I I I 1 I I I I I I I I
S5 10 15 20 25 30
S1:+ S2:e
0
30
A f I I I IM I I
OCT.,1992
Figure 11-19: Representative Wave Period, Significant Wave Height, Central
Direction and Spreading Parameters, October, 1992.
II-20
I1 1 1 11 1 1 1 I II I III I III II III I
.,~,~~~......,....,.~,. --....,. --,1711 111-ll~lr--11111 111 1
I
I
8 O
$$ g 8 O
PERDIDO KEY: RANGER STATION
1.0
0.8
Uc 0.6
(M/S)
0.4L
0. 2
u.
8C
(DEG)
S 5 10 15 20 25 30
+
+ ++ + +
++ + + + +
*. *4 4+4-4+4- 4-+H-4+
+ +
++- +
I I I I I I I I I I I I I I I I I I I I I I I I
5 10 15 20 25 30
OCT. 1992
Figure 11-20: Magnitude and Direction of Mean Current and Tidal Stage,
October, 1992.
1-21
A n l l I
4- 4.-$O+-4H++H4- 4+ 4.I.4++
4+4-444 ++ +
+++ t4 I 1 ++ 1 1+ 1 + 1 + 1 + ++
i f i l l l l i l l il I I I+f 1 1 I4 + 1+ 1 I I
I i a a aII I I I I I I I I I I I I Ii I I I I I I
PERDIDO KEY: RANGER STATION
20
15
TH 10
(SEC)
5
0
3
1 5 10 15 20 25 30
++ ++++ +++ + 4 +++ +
+ + + + "I +' + +
S + + +
N + + + + ++ +
+
+ ++
E+ + + +
E ++ + + +
++ ++
++ + + + + + +
+ + ++ ++
H 1 11 i 1 1 1 i 1+ F t 1 11 i 1 1. 1 1 1 1 I
1 5 10 15 20 25 30
,0
'0 ~ ~ |-----------0--------------
S3i+ Sa0:
30 -
90
o
0 o e e o
So 1 2 5
1 5 10 IS 20 25 30
NOV., 1992
Figure II-21: Representative Wave Period, Significant Wave Height, Central
Direction and Spreading Parameters, November, 1992.
II-22
1 5 10 15 20 25 30
S (
PERDIDO KEY: RANGER STATION
1.0
0.8
Uc 0.6
(M/S)
0.4
0.2.
0.0
N
ec E
(DEG)
S
N
2
1
TIDE
(M
0
-1
-2
e H_+ Lt...p++H H+- 4- *f#-+'=l- *+-+-H-+H H+t-'--- 4++H-+4-+ -H H 4H-W l+- t.-h
+ ++ + -++4+-4 2+ +
1 1 1+1+ 1 1+ 1+1 I I I I 1 I 1+ 1+1+1 1+1+1+11+1
1 5 10 15 20 25 30
+ + +
4--1
-4
++ + + + +
II -I 4- + ++ + -
1 5 10 15 20 25 30
o5 1 1s 20 25 30
I I I I I I I I I I I I I I I I I I I I I I I I I I I I I
1 5 10 15 20 25 3C
NOV. ,1992
Figure 11-22: Magnitude and Direction of Mean Current and Tidal Stage,
November, 1992.
11-23
PERDIDO KEY: RANGER STATION
20
15
Tn 10
(SEC)
5
0
4
3
Hs 2
1 5 10 15 20 25
90
60
+ + + +4 ++ +
+ + + + + +-
+ + +
+ + + + +
+ +++ +++
+ + +
++ +
I I I I 14 I I I I I I L 1II I I I I I III
5 10 s15 20 25 30
DEC.,1992
Figure 11-23: Representative Wave Period, Significant Wave Height, Central
Direction and Spreading Parameters, December, 1992.
1-24
I I I I I I I I I I I I I I I I I I I I I I I I I I I I
S1:+ S2:.
II Q
PERDIDO KEY: RANGER STATION
0.8 I-
0.2 -4H W-H^ + S." .+. ++ -^I "t-. +.--H- +
++ ++ + + +++
nI n ii+ + 1+-1 I 1 I i i 1 + I I 1+4-
8C
(DEG)
1 5 10 15 20 25 30
+ +
+ +
+ + + + +
+ +
I I I I I 4 1 I I I I I I I I I I I I I I I I I I I I
1 5 10 IS 20 25 30
1
DEC. 1992
Figure 11-24: Magnitude and Direction of Mean Current and Tidal Stage,
December, 1992.
11-25
Uc 0.6
(M/S)
I1 1 1 1 1 1 1 1 1 II III III III III I I II
20
15
TM 10
(SEC)
5
0
N
8 E
S
w
120
90
S 60
30
PERDIDO KEY: CAUCUS SHOAL
5 10 15 20 25 30
1 5 10 15 20 25 30
+ +H+++ + +-
+ +4
+++
1 5 10 15 20 25 30
S1:+ S2:O
Io +
i i
S0 000
0S4:+ S<
- 1 1
~VOg O
5 30
APR, 1992
Figure 11-25: Representative Wave Period, Significant Wave Height, Central
Direction and Spreading Parameters, April, 1992.
II-26
PERDIDO KEY: CAUCUS SHOAL
0.8 P
0.2
1 5 10 15 20 25 30
+
+ + + +1+ ,+
++ + + +
+ +
+
15 10 15 20 25 30
RPR, 1992
Figure 11-26: Magnitude and Direction of Mean Current and Tidal Stage,
April, 1992.
11-27
Uc 0.6
(M/S)
O.4l
+ +
+
+ *+++++ ++++
0.0
N
9c
(DEG)
I 1 1 1 1 1 1 1 1 I I I I I I I I I I I I I I I
.
,
PERDIDO KEY: CRUCUS SHOAL
20
15
TH 10
0
3
1 5 10 15 20 25 30
1 5 10 15 20 25 30
-- .---- h, I.. I
1 5 10 15 20 25 30
120
o Si:+ S2:*
90
go
S 60- o
oo "o o :o o o
30
0 101
1 5 10 15 20 25 30
MY. ,1992
Figure II-27: Representative Wave Period, Significant Wave Height, Central
Direction and Spreading Parameters, May, 1992.
II-28
++ + + +.+ +,,
+
SI I i i I I I ,I I I I I + I I +
i
I
PERDIDO KEY: CAUCUS SHOAL
1.0
0.8
Uc 0.6
(M/S)
0.4
0.2
0.0
N
N
8c
(DEG)
1 5 10 15 20 25 30
S + ++ +
S + + + +++ + + ++
++ ++F + + + + + + + + ++++++ + +
"- + ++- +44
+
+
1 5 10 15 20 25 30
M 0
-1
1 5 10 15 20 25 30
MAY.,1992
Figure II-28: Magnitude and Direction of Mean Current and Tidal Stage,
May, 1992.
II-29
i
PER0IDO KEY: CAUCUS SHOAL
20
15
Tn 10
(SEC)
5
0
4
3
120
90
S 60
30
0
1 5 10 15 20 25 3(
+-I+ + +
+ +
+ +4+H-+
+
+ + + + +
+L+ + ++ +
+1" 1 I I I I 1 I I I 4 1 I I I I I I I I I I I I I I
+I I 11 1 1 11Ili
1 5 10 15 20 25
JUN.,1992
Figure 11-29: Representative Wave Period, Significant Wave Height, Central
Direction and Spreading Parameters, June, 1992.
11-30
s-Fi~ I II II II II II II
|
RSS
HIDE
