o shipwreck beach, kauai, hawaiithe shipwreck beach study area (transects 0– 20) is located on the...

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429001001 429001009 429001007 429001002 429001010 428021001 429001003 429001008 428020008 428021041 429001004 428028999 30" 20" 10" 50" 159 o 26' W 40" 159 o 25'10" W 20" 159 o 26'30" W 30" 20" 10" 50" 159 o 26' W 40" 159 o 25'10" W 20" 159 o 26'30" W 21 o 53' N 21 o 52'10" N 40" 30" 50" 21 o 53'10" N 20" 21 o 53' N 21 o 52'10" N 40" 30" 50" 21 o 53'10" N 20" 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 65 64 66 67 456800mE 454400mE 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 65 64 66 67 456800mE 454400mE 89 90 91 92 93 94 95 96 97 98 99 87 86 88 24200 01 02 03 04 2420500mN 85 2418400mN 89 90 91 92 93 94 95 96 97 98 99 87 86 88 24200 01 02 03 04 2420500mN 85 2418400mN AREA DESCRIPTION The Shipwreck Beach study area (transects 0– 20) is located on the southeast coast of Kauai. The shoreline is composed of carbonate sand beach interrupted by basalt headlands. Overall, the area is experiencing erosion at an average rate of -1.2 ft/yr. Previous studies 1 found similar trends in shoreline change for the Shipwreck Beach study area. 1 Makai Ocean Engineering and Sea Engineering, 1991 Aerial Photograph Analysis of Coastal Erosion on the Islands of Kauai, Molokai, Lanai, Maui, and Hawaii. State of Hawaii Office of Coastal Zone Management Program. HISTORICAL SHORELINES Erosion rate measurement locations (shore-normal transects) Historical beach positions, color coded by year, are determined using orthorectified and georefer- enced aerial photographs and National Ocean Survey (NOS) topographic survey charts. The low water mark is used as the historical shore- line, or shoreline change reference feature (SCRF). Movement of the SCRF along shore-normal transects (spaced every 66 ft) is used to calcu- late erosion rates. T-sheet 1927 May 2000 Apr 1975 Jan Mar 1982 1988 1987 Jul Oct 2007 Erosion Rate Accretion Rate SHORELINE CHANGE RATES Historical shoreline positions are measured every 66 ft along the shoreline. These sites are denoted by yellow shore-perpendicular transects. Changes in the position of the shorelines through time are used to calculate shoreline change rates (ft/yr) at each transect location. Annual shoreline change rates are shown on the shore-parallel graph. Red bars on the graph indicate a trend of beach erosion, while blue bars indicate a trend of accretion. Approximately every fifth transect and bar of the graph is numbered. Where necessary, transects have been purposely deleted to maintain consistent alongshore spacing. As a result transect numbering is not consecutive everywhere. The rates are smoothed alongshore using a 1-3-5-3-1 technique to normalize rate differences on adjacent transects. -3 -2 -1 0 -3 -2 -1 0 Shoreline Change Rate (ft/yr) 0 5 10 15 20 Shipwreck Beach, Kauai, Hawaii 400 300 200 1200 900 600 100 300 0 0 100 300 Scale 1:3000 Meters Feet Contract C25514 Contract 7249 Charles Fletcher, Matthew Barbee, Siang-Chyn Lim, Julia Ehses, Matt Dyer, and Ayesha Genz University of Hawaii Coastal Geology Group School of Ocean and Earth Sciences and Technology 1680 East West Road, Honolulu, HI 96822, U.S.A. The preparation of this poster was financed in part by the Coastal Zone Management Act of 1972, as amended, administered by the Office of Ocean and Coastal Resource Man- agement, National Ocean Service, National Oceanic and Atmospheric Administration, United States Department of Commerce, through the Office of Planning, State of Hawaii. Latitude/Longitude coordinates UTM coordinates 159 o 26'30" W 2418400mN 0 0 10km 10mi Kauai Shipwreck Beach N 0 5 10 15 20 Shipwreck Beach Keoniloa Bay Makawehi

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Page 1: o Shipwreck Beach, Kauai, HawaiiThe Shipwreck Beach study area (transects 0– 20) is located on the southeast coast of Kauai. The shoreline is composed of carbonate sand beach interrupted

429001001

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30"20" 10" 50"159o26' W 40" 159o25'10" W20"159o26'30" W

30"20" 10" 50"159o26' W 40" 159o25'10" W20"159o26'30" W

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45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 6564 66 67 456800mE454400mE

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AREA DESCRIPTIONThe Shipwreck Beach study area (transects 0– 20) is located on the southeast coast of Kauai. The shoreline is composed of carbonate sand beach interrupted by basalt headlands. Overall, the area is experiencing erosion at an average rate of -1.2 ft/yr. Previous studies1 found similar trends in shoreline change for the Shipwreck Beach study area. 1 Makai Ocean Engineering and Sea Engineering, 1991 Aerial Photograph Analysis of Coastal Erosion on the Islands of Kauai, Molokai, Lanai, Maui, and Hawaii. State of Hawaii Office of Coastal Zone Management Program.

HISTORICAL SHORELINES

Erosion rate measurement locations(shore-normal transects)

Historical beach positions, color coded by year, are determined using orthorectified and georefer-enced aerial photographs and National Ocean Survey (NOS) topographic survey charts. The low water mark is used as the historical shore-line, or shoreline change reference feature (SCRF).

Movement of the SCRF along shore-normal transects (spaced every 66 ft) is used to calcu-late erosion rates.

T-sheet 1927

May 2000

Apr 1975Jan

Mar

1982

19881987Jul

Oct 2007

Erosion RateAccretion Rate

SHORELINE CHANGE RATES

Historical shoreline positions are measured every 66 ft along the shoreline. These sites are denoted by yellow shore-perpendicular transects. Changes in the position of the shorelines through time are used to calculate shoreline change rates (ft/yr) at each transect location.

Annual shoreline change rates are shown on the shore-parallel graph. Red bars on the graph indicate a trend of beach erosion, while blue bars indicate a trend of accretion. Approximately every fifth transect and bar of the graph is numbered. Where necessary, transects have been purposely deleted to maintain consistent alongshore spacing. As a result transect numbering is not consecutive everywhere. The rates are smoothed alongshore using a 1-3-5-3-1 technique to normalize rate differences on adjacent transects.

-3

-2

-1

0 -3

-2

-1

0

Shoreline Change Rate (ft/yr)

0

5

10

15

20

Shipwreck Beach, Kauai, Hawaii

400 300200

1200 900600

100

3000

0100

300

Scale 1:3000Meters

Feet Contract C25514 Contract 7249

Charles Fletcher, Matthew Barbee, Siang-Chyn Lim,Julia Ehses, Matt Dyer, and Ayesha Genz University of Hawaii Coastal Geology GroupSchool of Ocean and Earth Sciences and Technology1680 East West Road, Honolulu, HI 96822, U.S.A.

The preparation of this poster was financed in part by the Coastal Zone Management Act of 1972, as amended, administered by the Office of Ocean and Coastal Resource Man-agement, National Ocean Service, National Oceanic and Atmospheric Administration, United States Department of Commerce, through the Office of Planning, State of Hawaii.

Latitude/Longitude coordinatesUTM coordinates

159o26'30" W2418400mN

0

0 10km

10mi

Kauai

Shipwreck Beach

N

0

5

10

15

20

ShipwreckBeach

KeoniloaBay

Makawehi