基于模拟优化模型的干旱风沙草原区水-粮食-能源关系

定量分析干旱风沙草原区水-粮食-能源(WFE)关系,可为制定草原区生产、经济和生态环境等政策提供科学的支持.采用基于Python语言的 MODFLOW模型——FloPy,在考虑研究区牧草产量和灌溉能源消耗的基础上,构建了一个紧密耦合干旱风沙草原区WFE系统理想案例的多目标模拟优化模型,并使用多目标优化工具Pymoo框架下的NSGA-Ⅱ算法进行了求解.结果表明:所构建的模拟优化模型可以定量计算干旱风沙草原区的WFE关系,Pymoo提供的NSGA-II算法在WFE关系多目标优化中具有较好的搜索效率与稳定性;使用权重w_x对设定的6种方案进行对比分析,一般年(方案1—3)与干旱年(方案4—6)的地下水水位差最大值分别为1.15,1.43,1.34,0.96,1.26,1.15 m;一般年和干旱年灌溉水量最大可减少136.90%和134.37%,作物产量增加18.60%和18.31%,节省能源26.94%和27.89%.

WFE nexus in arid sandy grassland based on simulation optimization model

Quantitative analysis of water-food-energy nexus of an arid sandy grassland, can provide scientific support for ecosystems that improve the grassland. The Python language-based MODFLOW model—FloPy was used, constructing the multi-objective simulation optimization model of the WFE system, considering the alfalfa production and irrigation energy consumption of research area, the NSGA-Ⅱ algorithm of the framework of multi-objective optimization tool Pymoo was used to solve the problem. The results show that the optimization model can quantify the WFE nexus of the semi-arid sandy grassland, and the NSGA-II algorithm provided by Pymoo has outstanding search efficiency and stability in the multi-objective optimization of WFE nexus; According to the comparative analysis of the six schemes set by the weight w_x, the maximum difference of groundwater level in general year(scheme 1 to scheme 3)and drought year(scheme 4 to scheme 6)is 1.15, 1.43, 1.34, 0.96, 1.26 and 1.15 m, respectively; In general year and drought year, irrigation water can be reduced by 136.90% and 134.37%, crop yield can be increased by 18.60% and 18.31%, and energy can be saved by 26.94% and 27.89%.