Wednesday, November 15, 2006

Effects of Polyacrylamide Treated Soils on Water Seepage in Unlined Water Delivery Canals.

Jianting Zhu, Michael Young, and Ernesto Moran. Desert Research Institute, 755 E Flamingo Road, 755 E Flamingo Road, Las Vegas, NV 89119, United States of America

Polyacrylamide (PAM) is recently being used as a water conservation tool to reduce water seepage loss in unlined water delivery canals.  It has been shown that PAM treatments can either increase or decrease water infiltration into soils, depending on the type and concentration of polymer applied, soil type, and application protocol.  In this study, we examine the impact of the presence of a thin PAM treated soil layer on the seepage loss to the soils, and identify the most important hydraulic parameters that affect overall water loss to the soils, using a wide range of both experimentally determined and estimated hydraulic parameters. The soil treated with PAM is considered as having two distinct layers where the upper layer is PAM and fine-grained soil material, and the underlying soil is the native material.  This allows us to consider the uppermost layer as having distinctly different hydraulic properties. The water infiltration scenarios will be conceptualized as two layer systems (PAM-treated and native soils) with a constant head on top (i.e., relatively constant water level in the canals).  Water infiltration is simulated through this two-layer system and the results can be used to predict percolation under different hydraulic and other environmental scenarios.  Sensitivity analysis is also carried out to find out the most sensitive parameters.

Handout (.ppt format, 4561.0 kb)