Multi-Objective Evaluation Model of Groundwater Carrying Capacity in Irrigation District

Abstract

As groundwater resource in irrigation district is affected by many factors,evaluation of groundwater carrying capacity is a multi-objective optimal problem.A multi-objective quantitative evaluation model was established, which included four objectives,i.e.,GDP, grain yield, population and COD emissions. The improved Differential Evolution (DE) algorithm was built and adopted to solving the multi-objective evaluation model. In order to improve the population's diversity and the ability of escaping from the local optimum,a self-adapting crossover probability factor was presented in DE algorithm. Furthermore,a chaotic sequence based on logistic map was employed to self-adaptively adjust mutation factor based on linear crossover. Dynamic penalty function,to transform the constrained problem to unconstrained one, was employed. The multi-objective quantitative evaluation model was applied to evaluate groundwater carrying capacity of People's Victory Canal irrigation district in different frequency year. The result shows that, with groundwater resource increasing, all objectives of groundwater carrying, including GDP, population, grain yield and COD emissions, in 50% frequency year are more than in 75% frequency year.