RESPONSE OF AN UNCONFINED AQUIFER DUE TO THE TIME VARIANT RECHARGE AND RIVER STAGE FLUCTUATION

Abstract

The response of an unconfined aquifer bounded by two ri\ er rivers, to time variant recharge and change in river stage has been found out. The solution for a time variant recharge and unsteady river stage has been sought using the solution of Boussinesq' s equation for one. dimensiona.L. seepage corresponding to uniform time invariant recharge and a step rise in river stage by mak-ing use of Duhama.i' s approach. The recharge rate and one of the two river stages are assumed to be exponentia-l.Ly decaying function of time. The variation of base f.Low with time resulting from recharge and river stage fluctuation are presented separately for different length of the aquifer and for different co-efficients of transmissibility. The base flow due to simultaneous change in river stage and unsteady recharge can be found out from these results by algebraic addition.