基于SD变化环境下农业水资源供需平衡模拟

为了探讨变化环境对农业水资源供需平衡的影响,运用系统动力学软件Vensim-Dss建立了农业水资源供需平衡的系统动力学模型,综合考虑社会经济发展和气候变化情景,仿真模拟了变化环境下农业供、需水量及缺水量的变化情况.石羊河流域模拟结果表明:未来农业供水量和需水量受气候变化的影响程度不同,但 2033年以后,农业供水量在不同气候变化情景下的变化趋势相同;不同行政区农业水资源系统对气候变化的响应存在明显差异,金昌市A2气候情境缺水率大于B2情景,在2029年、2038年缺水率分别达到32.0%,28.6%, B2情境下,2021年开始出现轻度缺水,中度缺水年仅出现在2023年和2039年,缺水率分别为30.7%,30.5%;武威市A2气候情境下缺水率小于B2情景,仅2038年为中度缺水,缺水率为24.9%,B2气候情景中度缺水年较多,2023年缺水率最大,达到33.2%.研究结果可以对变化环境下区域用水规划和农业发展规划提供指导.

System dynamics model-based simulation of agricultural water resources supply and demand balance in changing environments

A system dynamics model for supply and demand balance of agricultural water resources has been established using system dynamics software Vensim-Dss to simulate variations in agricultural water supply,demand and deficit in a changing environment.The social and economic development and climate changing scenarios were considered in the model and the impacts of changing environment on the supply and demand balance of agricultural water resources were explored.In terms of Shiyang River Basin,the results show that the extent of influence of climate change on the future agricultural water supply differs from that on the water demand.After 2033,however,the variation trends of the agricultural water supply in A2 and B2 climate scenarios are identical.The response of the agricultural water resources system to climate change in one administrative district is different from that in the other district significantly.In Jinchang Administrative District,for example,the water deficit ratio in Scenario A2 is greater that in Scenario B2,and it will arrive at 32.0%and 28.6%,respectively,in 2029 and 2038.In Scenario B2,mild water deficit will start to occur onwards 2021,and moderate water deficit should only appear in 2023 and 2039,with 30.7%and 30.5%water deficit ratios,respectively.Regarding to Wuwei Administrative District,the water deficit ratio in Scenario A2 is smaller that in Scenario B2.Specially,in Scenario A2,moderate water deficit just appears in 2038 with 24.9%water deficit ratio.In Scenario B2,however,more years will suffer from moderate water deficit,especially,the year 2023 can be subject to the most severe water shortage with a deficit ratio as large as 33.2%.These results can provide guidance on regional water utilization planning and agricultural development planning in a changing environment.