An optimal water allocation model based on water resources security assessment and its application in Zhangjiakou Region, northern China

Problems with water resources security (WRS) resulting from water scarcity are occurring worldwide, and the most feasible solution to such problems is to increase the productivity of limited water resources through rational water use allocation within the affected region. In this study, an optimal water allocation model (OWAM) based on WRS assessment was developed and applied to improve the water use benefits in Zhangjiakou Region of northern China in 2020. The OWAM was an optimal linear programming model that comprehensively considered eco-environmental and socio-economic benefits. Some WRS assessment indicators that can be easily adjusted, including the ratio of ecological water to total water demand, surface water pollution index, exploitation ratio of water resources, water supply per capita, industrial water scarcity, and agricultural water scarcity, were incorporated into the OWAM as constraining conditions. The model had different solutions corresponding to four WRS statuses (quite safe, basically safe, unsafe, and extremely unsafe). The results indicated that optimal water allocation determined using this model met the domestic and environmental water demand, and led to increased water use benefits within the region when compared with before allocation. The benefits of basically safe status were bigger than those of unsafe status. In contrast to the conventional OWAM, the developed model could help to assure sustainable water use at the regional scale when used in combination with WRS assessment. (C) 2012 Elsevier B.V. All rights reserved.