EFDC_Explorer provides the user with several methods of generating the cell bottom elevations from the input topographic data. The following discussion addresses each option.
The following three options do not require a topographic data file. They can be used for quicker model generation or building test or evaluation models.
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Bottom Slope - J Direction:Applies a constant bed slope to the cells in the J direction, starting with a specified initial bottom elevation. If the entered slope is positive the bottom elevations will decrease with higher J's. The inverse is true if the entered slope is negative.
The following three options do require a topographic data file to be specified.
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Use Z at Cell Centroid:Use this option if the topographic data is relatively sparse as compared to the grid. This approach uses the inverse distance interpolation scheme to compute the elevation at the X and Y of the cell centroids.