Possible mechanisms for leakage between aquifers and rivers

Abstract Leakage between aquifers and rivers is studied using an idealised one-dimensional problem. Various leakage mechanisms are introduced and the effects on heads in the aquifer and flows to the river are noted. Leakage is represented by a linear coefficient, a non-linear coefficient and combination of the two. Leakage is also modelled direcly as a known flow. It is shown that base-flow recessions are effectively independent of the magnitude of the linear leakage coefficient.