Optimal Water Allocation Of Shi-yang River Basin Based On Analysis Of Water Balance

Shiyang River Basin is the area with the longest history of irrigation,biggest population density,highest utilization of water resources,sharpest contradiction between water demand and water supply,the most serious environmental problems in the northwest inland river basins, where the water resources limited the economical development largely.Henceforth,under the scientific technology and method,allocating the limited water resources to main the optimal goal,is of vital importance to solve the problems of shortage of water resources and unbalance between water demand and supply.On the water balance analysis of 2010,using the methods of linear programming combination with computer software MATLAB,the water resources was allocated according to the largest output value,and the following results were gotten:(1)Taking 2000 as the present year,the calculation and analysis of water demand and supply in 2010 was made according to the present water supply projects scale,crop types,crop areas,domestic water,industrial water and water resources planning of Shiyang River Basin. The results showed that in 2010,the total demand water was 22.8×l0~8m~3,with 15.94×10~8m~3 for agriculture irrigation,1.0×l0~8m~3 for forestry,3.74×l0~8m~3 for industry,0.60×l0~8m~3 for civil domestic use and 1.52×l0~8m~3 for rural water domestic use.It showed that the water for irrigation accounted for 69.9%of the total water,which is still the biggest water user.(2)In 2010,the water supply in Dajinghe system is 0.14×l0~8m~3,water shortage is 0.09×10~8m~3,with the water shortage ratio of 69.72%.The water supply in Xidahe system is 4.25×l0~8m~3,water shortage is 1.67×l0~8m~3,with the water shortage ratio of 41.92%.The water can keep balance in other research units.It showed that the water projects in the river basin can largely improve the water shortage and restrain the over-exploitation of under-ground water.(3)On the basis of water balance,taking into the environmental water use first,taking the largest output value as the goal,the water resource was allocated according to the different water users and the value of forestry.Then the optimal water allocation model was established and solved with the adoption of MATLAB.It showed that in 2010,the total water supply is 21.06×l0~8m~3,with 9.65×l0~8m~3 for industry,8.55×l0~8m~3 for agriculture irrigation, 1.96×10~8m~3 for forestry irrigation,0.42×10~8m~3 for civil domestic use and 0.48×l0~8m~3 for rural domestic use.The total value was 9734.88×10~8 yuan.