Effect of shallow penetration and streambed sediments on aquifer response to stream stage fluctuations (analytical model)

An analytical model of stream-aquifer interaction is proposed that considers the effects from a small degree of aquifer penetration and low-permeability sediments on the head response to an arbitrary stream-stage hydrograph. Aquifer sections under the stream and beyond are considered in a single model. The model of ground water flow in the aquifer is based on the Dupuit assumptions corrected for leakage from the stream. The model can use stream-stage hydrographs in both analytical and tabular forms. The nondimensional linear boundary value problem is solved for hydraulic head in the aquifer using numerical Laplace transforms and a convolution algorithm. The proposed solution is used to assess the impact of shallow penetration and low-permeability streambed sediments on head responses by comparison with available solutions which neglect these factors.