TN-15 : Seepage from water bodies

Abstract

A mathematical model for seepage studies from two parallel canals has been developed and interference of two parallel canals is studied. One of the canals is situated on a high ridge and is not hydraulically connected with the aquifer. The other canal situated at a lower level has hydraulic connection with the aquifer. Its seepage rate is controlled by the water table position in the aquifer and is linearly dependent on the difference in the potentials at the canal and in the aquifer underneath. In this present study the temporal variation of seepage from the canal hydraulically connected with the aquifer has been quantified. The model predicts the time at which the-seepage from the canal having hydraulic connection with the aquifer reduces to zero and quantifies the rate at which the canal receives water as a drain.

Recently there have been evidences that the exchange flow rate between a canal and a hydraulically connected aquifer can be very non-linear. In the present report seepage from a single canal when water table lies at a shallow depth has also been studied for a case in which the seepage rate has an exponential relation with the potential difference between the canal and the aquifer. The seepage rates corresponding to the linear and non linear relations have been compared.