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<br />27 <br /> <br />o <br />..,J <br />CJ1 <br />00 <br /> <br />Q = AKdh = Al K'l dhl + A2K'2 dh2 + .. +AnK'n dhn <br /> <br />(9) <br /> <br />dx <br /> <br />dXl <br /> <br />dx2 <br /> <br />dxn <br /> <br />where An is the nth model strata area, and K'n and dhn are the strata <br />dXn <br /> <br />hydraulic conductivity and hydraulic gradient, respectively. Under <br /> <br />most conditions of unconfined aquifers, the hydraulic gradients are <br /> <br />the same and can be cancelled from both sides of Eq. 9, but in the <br /> <br />Grand Valley, an underlying cobble aquifer is partially confined such <br /> <br />that gradient cancellation is impossible. <br /> <br />The value computed for the outflow in Eq. 9 will not be <br /> <br />comparable in magnitude to the expected values because the model <br /> <br />strata areas are determined according to the ratio of actual strata <br /> <br />depths with the width factor being some convenient unit width. To <br /> <br />make the necessary adjustments to the field measurements, the model <br /> <br />values of Ki are determin<;>d from the values of ground water outflow <br /> <br />from subroutine WATER. The equation describing this adjustment is, <br /> <br />Ki = TGWOF (K'i)/value obtained from Eq. 9........... (10) <br /> <br />where Ki is the. adjusted model hydraulic conductivity. Because the <br /> <br />time interval is on a monthly basis, there will be monthly values of <br /> <br />model hydraulic conductivity computed for each strata which become <br /> <br />equal when the ground water outflows are in line with the strata <br /> <br />characteristics. Wj:len this criteria has been satisfied, the modeling <br /> <br />is complete and future computations can start at this point. <br />