基于SD模型的石羊河流域中下游水资源承载力初步研究

在深入分析石羊河流域中下游＂水-生态环境-社会经济＂复合系统的基础上,运用系统动力学方法,建立了包括8个一级系统、27个状态变量、27个速率变量、65个辅助变量、31个表函数、41条反馈回路及191个SD（System Dynamics）方程的水资源承载力系统动力学模型.选取水浇地灌溉面积增长率、水浇地灌溉定额、水浇地灌溉水利用系数、菜田灌溉定额、菜田灌溉水利用系数等5个参数作为方案设计的决策变量,设计了四种方案,在对各方案水量供需关系模拟分析的基础上,以加大农业节水力度、平水年可供水量为约束条件,通过SD模型模拟计算了各规划年研究区可承载的水浇地灌溉面积及社会经济与生态规模.

Preliminary Study on Water Resources Carrying Capacity in the Middle and Lower Reaches of Shiyang River Basin based on SD Model

The complex system of ＂water-ecology environment-social economy＂ of the Shiyang River Basin is analyzed and a system dynamics model about water resources carrying capacity is built which includes 8 first-order systems, 27 level variables, 65 accessorial variables, 31 time functions, 41 feedback loops and 191 SD equations. Five parameters are selected as the decision variables for the scheme design, such as the growth rate of irrigation area of irrigable land, the irrigation quota of irrigable land, the utilization coefficient of the irrigation water of irrigable land, the irrigation quota of the vegetable fields, the utilization coefficient of the irrigation water of the vegetable fields and so on, and then four schemes are designed. On the basis of modeling and analyzing the relationship of water supply and demand under each scheme, the possible bearing irrigation area of irrigable land and the social economy and ecological scale are calculated in each planning year through the system dynamics model about water resources carrying capacity.