Irrigation Planning by Multilevel Optimization

Abstract

The complex problem of irrigation management in a large heterogeneous basin is solved by using a multilevel optimization technique. The real problem consists of determining the optimal cropping patterns in various subareas of the basin, the optimal design capacities of irrigation facilities including both the surface and ground water resources, and the optimal water allocation policies for the conjunctive use. The objective of such a management is to obtain a high level of economic efficiency in the irrigation development and water use system within a hydrologically feasible policy domain. Various alternative activities, such as surface water diversion and pumpage, ground water withdrawal and recharge, and alternative future operational scenarios, have to be analyzed in an integrated way. The solution strategy is based on the physical decomposition of a large system into interconnected subsystems. A computationally efficient algorithm that can be implemented in a microcomputer is developed to solve the multilevel linear programming model by an iterative procedure. A case study is presented to illustrate the application in a realistic situation.