Optimal Drain Design for Arid, Irrigated Areas

ABSTRACT A methodology and computer model are presented that can be used to identify economically optimum subsurface drainage systems in arid, irrigated regions. A simple optimization scheme is used to determine the least cost drain layout which will satisfy a specified design requirement. This optimization routine is imbedded in a larger simulation model of an irrigation-drainage system that evaluates the physical effects of installing this least cost drain system and predicts the resulting crop yield. By varying the design requirement systematically and comparing drain costs with the predicted values of increased crop yields, an optimum level of drainage and the minimum cost drain layout corresponding to this optimum level are determined.