特大城市水资源承载力政策响应的动态模拟

Dynamic simulation of policy implications for the water resources carrying capacity of megacities

基于系统动力学方法,建立一套集成政策、水量和经济人口指标的水资源承载力Stella动态模型,以北京市为案例,模拟有无政策干预下水资源承载力的响应特征.结果表明:以南水北调为主的政策调水使北京市水资源提前20年以上达到安全承载状态,反映出特大城市资源盈缺受人为影响强烈的特点;调水量在16亿m3左右时达到最适点,之后盲目增加调水量收效渐微;干旱年调水贡献更为突出.评价结果可为南北方水资源优化、保障城市水安全提供参考依据.

Water resources in the megacities could be affected by policies under certain circumstances, especially the water shortage cities in North China. A dynamic model of water resources carrying capacity(WRCC) integrated with policy, water resource, economic and population indicators was built using Stella software. The model was based on the method of system dynamics to simulate the response characteristics of WRCC with or without policy interventionsandtake Beijing as a case study. The results showed that the South to North Water Diversion policy will bring an early water security state in Beijing for twenty years in advance, which reflects that the water resources in megacities are strongly affected by human intervention. The optimum point of water transfer is 1.6 billion cubic meters.Beyond that, the effects of increasing water-transfer will be diminishing. Contribution in drought year is more prominent. The evaluation results can provide reference for the optimization of the water resources between north and south, and help to ensure the water security of the megacities.