STUDY OF CANAL SEEPAGE

Abstract

Analysis of seepage problems is not only required to quantify the seepage but also to understand the phenomenon such as water-logging, distribution of seepage forces and failures due to uplift pressures. In irrigated areas, canal seepage contribution to the subsurface reservoir can be substantial component of the total recharge. Better estimation of canal seepage in such areas can substantially improve the accuracy of estimation of sustained yield. Estimation of seepage quantity from canal is also required for economic justification of canal lining. A wide range of techniques exits for the study of steady state seepage conditions, namely Flow nets, Physical & Analog models and Mathematical models etc. Flow. net, which is graphical representation of family of streamlines and the corresponding equipotential lines within a flow region, is a valuable method employed for solving two-dimensional flow problems. The values of seepage quantity and potential at any point obtained by flow net are approximate at best. Sand-tank models (physical models) have been used for studying confined and unconfined flow problems. Capillary action, enclosed air, organic growth and unnatural tank boundaries of small sand models create problems. Steady state and two dimensional ground water flow can be investigated experimentally by Hele-Shaw model for complex boundaries. Correct representation of permeability requires accurate maintenance of spacing between plates and temperature of the fluid.