0 and 1. The value 0O describes complete blockage (no bypassing) and the 
value 1 describes complete bypassing (no groin). The bypassing factor, 
B , was defined through use of a rectangular distribution of the longshore 
transport rate and the depth of closure pertaining to the wave conditions at 
a particular time step: 
in which Dy is the depth at the seaward end of the groin and Do is the 
depth of closure given by Equation 2. A rectangular distribution of the 
transport rate provides a good approximation to available field data sets 
(Kraus and Dean 1987) and is also easily calculated. 
Summary 
105. In summary of the above, three kinds of information are required 
for shoreline simulation using GENESIS: 
a. initial conditions, such as initial position of the shoreline, 
positions and characteristics of structures, duration of time 
to be modeled, grid spacing, etc. 
Io 
wave conditions as a function of time to calculate the long- 
shore sediment transport rate. 
boundary conditions at the lateral ends of the beach. 
lo 
Model Calibration and Verification 
Introduction 
106. The general calibration procedure for GENESIS is to determine the 
transport parameters K, and Ky by reproducing measured shoreline change 
that occurred at the target site between two surveys. If sufficient data are 
available, the calibrated model is then run to simulate observed shoreline 
change that occurred in a time interval not spanned by the calibration, to 
verify that the calibration constants are independent of the time interval. 
Since wave data for these time intervals, which may cover years, are rarely 
available, it is common to use hindcast wave data. 
107. As discussed in Part-II, considerable shoreline position survey 
data are available for this coast. However, the standard calibration and 
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