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5 <br />change. The simulation of noncohesive (sand -size) sediment, including bed deposition <br />and resuspension, will be based the same high order advection -diffusion scheme used for <br />salinity and temperature. Sediment mass conservative methods will be used to simulate <br />topographic change of the sediment bed. <br />Model setup will include generation of a computational grid that includes the PEP Reef <br />project area and the appropriate onshore and alongshore extensions Existing tonoarannic <br />data from the on-going PEP Reef Monitoring Program will be used as input for grid <br />generation. Boundary conditions for the model will be developed from observed wave, <br />current, water elevation and meteorological data. The data set collected at the PEP Reef <br />site will be supplemented by data from the Sebastian Inlet Data Collection Program. In <br />particular, water level data collected at Sebastian Inlet at hourly intervals will be used to <br />drive the EFDC model at tidal frequencies. These data will be adjusted for the time lag <br />between Sebastian Inlet and Vero Beach before being used as a boundary condition for <br />the model. <br />3.2 Model Calibration <br />Calibration involving comparison of predicted and measured processes will be carried out <br />in the statistical sense on the hydrodynamic results. Wave and current data now being <br />measured with accuracy at the seaward boundary of, and within the PEP Reef field will <br />be used in this process. These data can be directly compared with model output to check <br />calibration. Sediment transport and the resulting topographic changes in the nearshore <br />zone are much more difficult and expensive to measure with the degree of accuracy <br />characteristic of wave and current measurements. Furthermore, significant topographic <br />changes occur episodically and may not be fully represented by the sampling plan <br />consisting of profile data taken at fixed intervals. <br />Unlike the physics of hydrodynamics, the sediment transport process consisting of <br />suspension, lateral transport, deposition, and resuspension is a non -conservative process. <br />This makes direct observation of these processes in a field situation virtually impossible <br />at reasonable cost. Therefore, sediment transport models must rely heavily on laboratory <br />