Laserfiche WebLink
the k/m ratio and so being able to simply vary the one conductance value allows <br />one to essentially vary all the composite values over a range of reasonable values. <br />With the overall geometry of the stream within each cell fairly easy to measure, <br />such sensitivity analyses really can be best addressed to the k/m values. <br />Once the basic grid was established, the data input for all cells, and the boundary <br />conditions and stream system defined, the next step was to establish a calibrated <br />steady-state water table that matched the available data from the USGS reports <br />and maps. This was accomplished by setting an initial flat-lying head, adjusting <br />the constant head boundaries to match the incoming and outgoing heads, and <br />adjusting the general head boundaries to approximate the general gradient along <br />these boundaries. The model was then run under steady-state conditions and the <br />resultant head configuration compared to the desired target head configuration. <br />This was repeated with slight adjustments to the boundary head conditions until a <br />suitable and close match was achieved. At this point, the model was considered <br />ready for the predictive simulations. It is noted that a match to a single historic <br />head contour configuration is not necessarily an ideal calibration for a model. <br />However, given the complex nature of the stresses on the system, which change <br />on a daily basis, this match is the only feasible target given the available data and <br />is considered appropriate for the engineering calculation model constructed for <br />this study. <br />8 <br />Martin and Wood Water Couultants, Inc. <br />