GENESISGENEralized model for SImulating Shoreline change

*Starting page

Theoretical Considerations1. Governing Equation for Shoreline Change

2. Sand Transport Rates3. Depth of Closure4. Internal Wave Transformation Model

*Theoretical Consideration

1. Governing Equation for Shoreline ChangeThe equation governing shoreline change is formulated by conservation of sand volume.

Cross-section View of Sand Volume Balance

*Governing Equation for Shoreline Change

2. Sand Transport RateThe empirical predictive formula for the longshore sand transport rate used in GENESIS is:

The nondimensional parameters al and a2 are given bywhereH = Wave heightCg= Wave group speed given by linear wave theoryb= Subscript denoting wave breaking conditionqbs= Angle of breaking waves to the local shoreline

*Sand Transport Rate

3. Depth of Closure (Dc)1. The empirical predictive formula for depth of closure (Dc) is:

whereHo = Significant deep water wave heightLo= Deep water wave length2. Bathymetry surveys for depth of closure (Dc) is:Depth change at Oarai Beach, JapanBy Graphical, Depth of Closure is 7.5 m.

*Depth of Closure

4. Wave Transformation ModelOffshore wave transform to breaker line can be calculate by internal or external wave transformation model. The internal wave transformation model is submodel of GENESIS model, external model is optional model which used to calculate nearshore wave information to GENESIS.

Internal Wave Model Transformation External and Internal Wave Model Transformation

*Depth of Closure

4. Internal Wave Transformation ModelInternal wave transformation in GENESIS model was calculated through the following linear wave formulae:

Wave Transformation byRefraction and ShoalingRefraction CoefficientShoaling CoefficientWave Breaking

*Depth of Closure

Model ApplicationA. Input and Output

C. Calibration ParametersD. Example of Applying GENESIS Model to Coastal Erosion Project at Petchaburi to Pranburi River MouthB. Execution GENESIS Model

*Theoretical Consideration

A. Input and Output

Schematic of Input and Output File Structure of GENESISSTARTSHORLSEAWLWAVESSHORMSETUPOUTPTSHORC

*Theoretical Consideration

Input : START

The input file START.DAT contains the instructions that control the shoreline change simulation and is the principal interface between the modeler and GENESIS. After START file is prepared, typically only a few quantities in it will need to be changed during the course of verification, sensitivity testing and design optimization. The START file is consisted with 10 parts with the letter from A to J as following: AModel Setup BWaves CBeach DNon-Diffracting Groins EDiffracting (Long) Groins and Jetties FGroins/Jetties GDetached Breakwaters HSeawalls IBeach Fills JBypassing

*Theoretical Consideration

Input : SHORL

Example of SHORL File and Plot of ShorelineThis file contain data described initial beach location referenced to datum line. The following example SHORL file is the shoreline data of the figure below. Format of this file is, the description in first 4 lines and then shoreline location start at the fifth line which 10 data for each line.

*Theoretical Consideration

Input : SEAWL

Example of SEAWL fileThis file contain data described seawalls or structure with constructed parallel with shoreline which will protect erosion can not protrude over the structure such as road. In case of no such structure the value will be 9999. Format of this file is, the description in first 4 lines and then structures location start at the fifth line which 10 data for each line.

*Theoretical Consideration

Input : WAVES

Example of WAVES fileWave data contained in this file are wave period (s), significant wave height (unit as specified in A.2) and wave direction (deg).In the case of internal wave model was selected (in A.3) the WAVES file format is, the description in first 4 lines and then wave data start at the fifth line which wave period, wave height, wave direction and description for each line.Time step of wave data in each line will be specified in B.9If wave data given is not enough for model simulation in the period given in A.6 to A.7, the wave data will be reused.

*Theoretical Consideration

Input : SHORM

Example of SHORM fileThis file contain data described measure beach location referenced to datum line for using as calibration data. Format of this file is, the description in first 4 lines and then shoreline location start at the fifth line which 10 points data for each line.

*Theoretical Consideration

Output : OUTPT

This file record many type of results from GENESIS model which consist of:Project nameShoreline location in every time step which specified in A.9Longshore sediment transport rate in every time stepBreaking wave height and direction in every time stepLongshore sediment transport rate at the last time step Shoreline location at the last time step Location of contour line of input wave

*Theoretical Consideration

Output : SHORC

This file contains final shoreline location in the same format as SHORL file. This file can be rename to SHORL for using as input to continue the calculation. Following shoreline data can be plotted as show below.Example of SHORC File and Plot of Shoreline

*Theoretical Consideration

B. Execution GENESIS ModelTo execute GENESIS Model, input files as describe previously must be done.All of input file must have same extension and extension must not longer than 3 characters.Copy all input files to the same location with program name GENESIS.EXEExecute GENESIS.EXEModel will ask for project extension then input the extension name.All output will show at screen and record to 3 output files as describe previously.

Example of input and output files in the same location with GENESIS.EXE

*Theoretical Consideration

C. Calibration ParametersThere are two calibration parameters for calculation of longshore sediment transport rate which are K1 and K2 at line A.12 in START file. For sandy beaches experience has shown that values are typically in the ranges of 0.1 < K1 < 1.0 and 0.5 K1 < K2 < 1.5 K1 . Initial trial runs might use K1 = 0.5 and K2 = 0.25 . The transport parameter K1 controls the time scale of the calculation and is the principal calibration coefficient in GENESIS.Note: the above-mentioned values of K1 and K2 correspond to rms wave height. Significant wave height should be entered in the WAVES file, however, as GENESIS automatically converts heights in the wave file from significant to rms.

*Theoretical Consideration

D. Applying of GENESIS ModelD1. Introduction to the Coastal Erosion Project

D2. Study AreaD3. Input DataD4. Results

*Theoretical Consideration

D1. Introduction to the Coastal Erosion ProjectThailand have about 2,800 km of shoreline, many places are suffered due to coastal erosion problem example at north part of Thai Gulf from Maeklong river mouth to Bangpakong river mouth and shoreline from Leamluang beach to Pranburi river mouth. The project area, Petchaburi river mouth to Pranburi river mouth which about 105 km long, have severe beach erosion. There are many beach place coverage by the extend of study area, which are Leamluang beach, Chaosumran beach, Ban Tanodenoi beach, Puktien beach, Chaum beach, Huahin beach and Pranburi beach. Most of the beaches are white sand and nice place for tourism. Some places are the important historical places which are Marukatayawan palace and Klaikungwol palace. Then to provide appropriate management against such problems, it is important to study overall area.

*Theoretical Consideration

D1. Introduction to the Coastal Erosion ProjectCoastal Erosion Project Location (Petchaburi river mouth to Pranburi river mouth)

*Theoretical Consideration

D2. Study AreaExample of GENESIS model applied to sub area (Ban Paktale to Leampukbia) in Coastal Erosion Project will be shown in the next part. This sub area can be divide in to two sections for GENESIS model, due to large orientation of shoreline. The north part is from Ban Paktale to Ban Bangkaew, and the south part is from Ban Bangkaew to Leampukbia. The north part beach is lay north-south different with south part which laying northwest-southeast. At BanBangkaew, there were 14 detached breakwaters constructed in the year 1985 and there were many branches of Petchaburi river in this area.

*Theoretical Consideration

D2. Study AreaFigure Show Location of Ban Paktala, Ban Bangkaew and Leampukbia

Location of Ban Paktala, Ban Bangkaew and Leampukbia

*Theoretical Consideration

D3. Input Data

Arial Photo Show Shoreline Change from 1954 to 19761954Ban PaktalaBan BangkaewLeam Pukbia

*Theoretical Consideration

D3. Input Data

Arial Photo Show Shoreline Change from 1976 to 19951976Ban PaktalaBan BangkaewLeam Pukbia

*Theoretical Consideration

D3. Input Data

Location of Buoys of the National Research Council Of Thailand in The Upper Gulf of Thailand

*Theoretical Consideration

D4. Results

SETUP

OUTPT

SHORC

Show Graphical by GENGRAF.EXE

Calibration and Verification Results

*Theoretical Consideration

Calibration and Verification Results

Calibration and Verification

*Theoretical Consideration

Calibration and Verification Results

Calibration and Verification of North Part

*Theoretical Consideration

Calibration and Verification Results

Calibration and Verification of South Part

*Theoretical Consideration

Models are tools that can be misused and their correct or incorrect results misinterpreted.Ultimately, it is the modeler who has responsibility for results and actions taken, not the model.

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*End

ReferencesGravens, M. B., Kraus, N. C. and Hanson, H., 1989, GENESIS: Generalized Model for Simulation Shoreline Change; Report 2, /Workbook and System Users Manual, US Army Corps of Engineers, Washigton, DC.Hansom, H. and Kraus, N. C., 1989, GENESIS: Generalized Model for Simulation Shoreline Change; Report 1, Technical Reference, US Army Corps of Engineers, Washigton, DC.

*References

*Starting page*Theoretical Consideration*Governing Equation for Shoreline Change*Sand Transport Rate*Depth of Closure*Depth of Closure*Depth of Closure*Theoretical Consideration*Theoretical Consideration*Theoretical Consideration*Theoretical Consideration*Theoretical Consideration*Theoretical Consideration*Theoretical Consideration*Theoretical Consideration*Theoretical Consideration*Theoretical Consideration*Theoretical Consideration*Theoretical Consideration*Theoretical Consideration*Theoretical Consideration*Theoretical Consideration*Theoretical Consideration*Theoretical Consideration*Theoretical Consideration*Theoretical Consideration*Theoretical Consideration*Theoretical Consideration*Theoretical Consideration*Theoretical Consideration*End*References