|
June
2001 Survey
Field
Work
Ground
surveys were conducted at all 9 geotube projects along the upper coast.
Sixteen beach profiles were measured. A differential Global Positioning
System (DGPS) survey of the shoreline was conducted by driving the shoreline
feature while recording positions. A walking DGPS survey of the vegetation
line, or the top or base of the geotube if no vegetation line could be
walked, was also completed. During the walking survey the geotube was
described with the following characteristics:
| Exposure level
of apron, front, or top of geotube |
| Covered
(no exposure): geotube is completely covered with sediment |
| Minor:
small areas of geotube are visible in a few places |
| Partial:
geotube is fully exposed in intermittent sections |
| Full:
geotube is completely exposed |
| Geotube or ultraviolet
radiation shroud damage |
| None:
geotube is not damaged or undermined |
| Yes:
some damage |
| Vegetation cover |
| Visually
estimated percent of vegetation cover including top and front |
Results
The cumulative
length of geotube projects along the upper Texas coast as of the week
of June 11, 2001 was 10,171 meters (m) (6.32 miles (mi)). The geotubes
are in 9 separate installations (Table 1). Table 2 is a summary of the
conditions of the geotubes. A total length of 4,426 m (14,521 ft) of the
seaward faces of the geotubes was fully exposed. This length is approximately
44% of the total length of the projects. Although large portions of the
geotubes were exposed, they did not appear to have shifted position or
have significant damage. The only damage noted was the ultraviolet radiation
shroud on the Treasure Island projects. Table 3 lists the lengths of exposure
and damage for each project.
Table
1
Geotube
Project Lengths as of the Week of 11 June 2001
|
Geotube Project
|
Meters
|
Feet
|
Miles
|
|
Dellanera
|
484
|
1,588
|
0.301
|
|
Gilchrist east
|
1,891
|
6,204
|
1.175
|
|
Gilchrist west
|
4,390
|
14,403
|
2.728
|
|
Pirates Beach
|
2,604
|
8,543
|
1.618
|
|
Pocket Park II
|
117
|
384
|
0.073
|
|
Riviera
|
181
|
594
|
0.112
|
|
Treasure Island middle
|
127
|
417
|
0.079
|
|
Treasure Island north
|
299
|
981
|
0.186
|
|
Treasure Island south
|
78
|
256
|
0.048
|
|
Total
|
10,171
|
33,369
|
6.320
|
Table
2
Summary
of Geotube Damage and Exposure
along
the Upper Texas Coast
|
Upper Coast |
|
|
|
|
|
week
of 11 June 2001
|
Length
of exposure in meters
|
|
|
|
Covered
|
Minor exposure
|
Partial exposure
|
Full exposure
|
|
Apron
|
5419
|
420
|
0
|
4332
|
|
Front
|
4775
|
512
|
455
|
4426
|
|
Top
|
9096
|
0
|
0
|
1075
|
|
Total
|
|
932
|
455
|
9833
|
|
|
|
|
|
|
|
geotube damage
|
0
|
|
|
|
|
UV shroud damage
|
205
|
|
|
|
|
Total length=
|
10171
|
|
|
|
Table
3
Geotube
Damage and Exposure by Project
as
of the Week of June 11, 2001
|
Dellanera
|
|
|
|
|
|
15-Jun-01
|
Length
of exposure in meters
|
|
|
|
Covered
|
Minor exposure
|
Partial exposure
|
Full exposure
|
|
Apron
|
123
|
121
|
0
|
240
|
|
Front
|
289
|
0
|
68
|
126
|
|
Top
|
483
|
0
|
0
|
0
|
|
|
|
|
|
|
|
geotube damage
|
0
|
|
|
|
|
UV shroud damage
|
0
|
|
|
|
|
total length=
|
484
|
|
|
|
|
|
|
|
|
|
|
Gilchrist east
|
|
|
|
|
|
12-Jun-01
|
|
|
Length of exposure in meters
|
|
|
|
Covered
|
Minor exposure
|
Partial exposure
|
Full exposure
|
|
Apron
|
1537
|
0
|
0
|
354
|
|
Front
|
1209
|
0
|
171
|
510
|
|
Top
|
1891
|
0
|
0
|
0
|
|
|
|
|
|
|
|
geotube damage
|
0
|
|
|
|
|
UV shroud damage
|
0
|
|
|
|
|
total length=
|
1891
|
|
|
|
|
|
|
|
|
|
|
Gilchrist west
|
|
|
|
|
|
13-Jun-01
|
|
|
Length of exposure in meters
|
|
|
|
Covered
|
Minor exposure
|
Partial exposure
|
Full exposure
|
|
Apron
|
1203
|
0
|
0
|
3187
|
|
Front
|
934
|
0
|
216
|
3239
|
|
Top
|
3569
|
0
|
0
|
821
|
|
|
|
|
|
|
|
geotube damage
|
0
|
|
|
|
|
UV shroud damage
|
0
|
|
|
|
|
total length=
|
4390
|
|
|
|
|
|
|
|
|
|
|
Pirates Beach
|
|
|
|
|
|
14-Jun-01
|
|
|
Length of exposure in meters
|
|
|
|
Covered
|
Minor exposure
|
Partial exposure
|
Full exposure
|
|
Apron
|
2046
|
299
|
0
|
259
|
|
Front
|
2160
|
185
|
0
|
259
|
|
Top
|
2604
|
0
|
0
|
0
|
|
|
|
|
|
|
|
geotube damage
|
0
|
|
|
|
|
UV shroud damage
|
0
|
|
|
|
|
total length=
|
2604
|
|
|
|
|
|
|
|
|
|
|
Pocket Park II
|
|
|
|
|
|
15-Jun-01
|
|
|
Length of exposure in meters
|
|
|
|
Covered
|
Minor exposure
|
Partial exposure
|
Full exposure
|
|
Apron
|
117
|
0
|
0
|
0
|
|
Front
|
117
|
0
|
0
|
0
|
|
Top
|
117
|
0
|
0
|
0
|
|
|
|
|
|
|
|
geotube damage
|
0
|
|
|
|
|
UV shroud damage
|
0
|
|
|
|
|
total length=
|
117
|
|
|
|
|
|
|
|
|
|
|
Riviera
|
|
|
|
|
|
15-Jun-01
|
|
|
Length of exposure in meters
|
|
|
|
Covered
|
Minor exposure
|
Partial exposure
|
Full exposure
|
|
Apron
|
181
|
0
|
0
|
0
|
|
Front
|
66
|
115
|
0
|
0
|
|
Top
|
181
|
0
|
0
|
0
|
|
|
|
|
|
|
|
geotube damage
|
0
|
|
|
|
|
UV shroud damage
|
0
|
|
|
|
|
total length=
|
181
|
|
|
|
|
|
|
|
|
|
|
Treasure Island middle
|
|
|
|
|
11-Jun-01
|
|
|
Length of exposure in meters
|
|
|
|
Covered
|
Minor exposure
|
Partial exposure
|
Full exposure
|
|
Apron
|
0
|
0
|
0
|
127
|
|
Front
|
0
|
0
|
0
|
127
|
|
Top
|
0
|
0
|
0
|
127
|
|
|
|
|
|
|
|
geotube damage
|
0
|
|
|
|
|
UV shroud damage
|
127
|
|
|
|
|
total length=
|
127
|
|
|
|
|
|
|
|
|
|
|
Treasure Island north
|
|
|
|
|
|
11-Jun-01
|
|
|
Length of exposure in meters
|
|
|
|
Covered
|
Minor exposure
|
Partial exposure
|
Full exposure
|
|
Apron
|
212
|
0
|
0
|
87
|
|
Front
|
0
|
212
|
0
|
87
|
|
Top
|
251
|
0
|
0
|
49
|
|
|
|
|
|
|
|
geotube damage
|
0
|
|
|
|
|
UV shroud damage
|
0
|
|
|
|
|
total length=
|
299
|
|
|
|
|
|
|
|
|
|
|
Treausre Island south
|
|
|
|
|
|
11-Jun-01
|
|
|
Length of exposure in meters
|
|
|
|
Covered
|
Minor exposure
|
Partial exposure
|
Full exposure
|
|
Apron
|
0
|
0
|
0
|
78
|
|
Front
|
0
|
0
|
0
|
78
|
|
Top
|
0
|
0
|
0
|
78
|
|
|
|
|
|
|
|
geotube damage
|
0
|
|
|
|
|
UV shroud damage
|
78
|
|
|
|
|
total length=
|
78
|
|
|
|
|
