Research On Water Resources Optimal Allocation In Beijing-Tianjin-Hebei Region Based On Water Footprint

Beijing-Tianjin-Hebei Region is located in water-shortage district in China. It supplies 8 percent population, 6 percent of crop production and 10 percent of GDP, with less than 0.7 percent of water resources. That severe water shortage in this region has been obstructing the sustainable development of Beijing-Tianjin-Hebei Region. This research calculated the water footprint of five departments, such as agricultural department, industrial department, residental department, environmental department and virtual water trade, with the period 1994-2013 of Beijing-Tianjin-Hebei Region, building the SD model of water resources optimal allocation. Through analyzing four kinds of industrial restructure, the study finds the optimal solution for water shortage. In the last, by ranking the water economic productivity, this research finds the kind and quantity of fluctant products. The purpose of this research is to pursue the balance between the water supply and water demand. The conclusions are as follows.Firstly, the research calculates the water footprint of Beijing-Tianjin-Hebei Region with the methods of CROPWAT model and water quota. The average water footprint of Hopei province is 2226 m3/yr, and the average water footprint of Tianjin is 999 m3/yr, and the average water footprint of Beijing is 941 m3/yr. Hopei province is net exporter and Beijing is net importer, while the trade of Tianjin is balance. From the perspect of structure, agricultural water share 75.4 percent and environmental water share 18.3 percent, while the water footprint of eggs, meats, crop products share the main part of agricultural water, while the water footprint of affroestation share share the main part of environmental water.Secondly, the research builds the SD model of water resources optimal allocation with six subsystems. That is water-supply subsystem, agricultural water-use subsystem, industry water-use subsystem, residental water-use subsystem, environmental wateruse subsystem and economic subsystem. The model includes 70 variates. Through the conformance testing, historical data testing, sensitivity texting, the model is valid.Lastly, the result of policy simulation indicts that the optimal solution is the third one which Beijing-Tianjin-Hebei Region need import half of agricultural water. With this water policy, the supply-demand water will be balance in 2030 and the virtual water occupy the main part of water footprint, while saving agricultural water 800×108m3.In a word, the deriction of industry restructure is as follows.(1) the products of eggs, meats and milk should import 50 percent in 2030;(2) the products of crop will save water by 85 percent by improving the irrigation method, given to the security of crop;(3) cotton should export completely in 2030 because of the water waste and water pollution;(4) improving the structure of tree species and increasing the aquire of natural forests.