Method for calculation of available volume of water resources for northwest inland arid areas

An analysis was made on the process of water resources formation and dissipation in northwest inland arid areas. From the angle of ecological, producing, and domestic water consumption, the composite water resources system was divided into two separated, but interrelated systems, i.e. the social economic system and ecological environment system. With the perennial average gross volume of water resources taken as the restrictive condition, the large system and multi-objective optimal method was adopted for optimization of the two systems, and a coordination model was developed. By introduction of the vector analysis, the multi-objective problem was converted to the problem of single objective. By solving the model with the graphic method and the Kuhn-Tueken terms law, the social economic water demand, i.e. the available volume of water resources, was derived.