Evaluation of Groundwater Environment Carrying Capacity Based on Catastrophe Theory

Abstract

Evaluation of groundwater environment carrying capacity is a multi-objective, multi-criteria and multi-level comprehensive issue. Evaluation index system of groundwater environment carrying capacity was built and divided into some subsystems in accordance with each index's inherent stratification link. Every index's effect on carrying capacity system was obtained by normalization operations catastrophe-based, so the ultimate value of fuzzy membership function catastrophe-based, which explains the groundwater environment carrying capacity, can been calculated from the lowermost layer to the topmost layer. The method was applied to evaluate groundwater environment carrying capacity in People's Victory Canal Irrigation District. In order to reveal outer and inner factor's effect to groundwater system, evaluation index system was divided into 3 kinds of top-level subsystem, i.e., the development and utilization degree of water resources, economy society and eco-environment subsystem, which include 17 kinds of bottom-level sub-index. The comprehensive evaluation result catastrophe-based is 0.9282, 0.9212, and 0.9150 in 1995, 2000, and 2005 separately, and groundwater environment carrying capacity are all weak and shows a downtrend year by year along with rapid economy expanding. The result reveals that it is a fact that groundwater resources and eco-environment in irrigation district is increasingly prominent. As it is not necessary to define the weight of evaluation indexes in dynamic fuzzy comprehensive evaluation model catastrophe-based, subjectivity of the decision-making has been reduced. The examples show that the method in this paper is reasonable and feasible by fuzzy comprehensive evaluation method's validation.