30.-Determination of hydraulic conductivity using geophysical parameters in a ditch drainage system

Abstract

A steady state subsurface drainage problem between two parallel ditches / streams reaching up to the impermeable layer in a two layered horizontally heterogeneous aquifer, receiving constant rainfall/replenishment, was formulated. The analytical solution given by Shiv Kumar and Chauhan (1999) for phreatic surface in a two layered horizontally heterogeneous aquifer receiving constant replenishment, based on the steady state form of Boussinesq's equation, has been utilized to determine the hydraulic conductivity. The experiments were conducted on the Hele-Shaw model which was simulated for three sets of horizontal heterogeneity, three rates of replenishment and two ditch water levels. Dupit's relationship has also been used to develop the flow relationship for the two flow regions and determining the hydraulic conductivity. The theoretically predicted hydraulic conductivities for both the regions were compared with the model hydraulic conductivity. The two procedures of determining hydraulic conductivity from the drain flow data based on the proposed approaches were found to give reasonable results.