Analysis Of Water Environment Change And Optimization Of Water Resources Utilization In Qingwangchuan Irrigatedarea

YinDaRuQin irrigation project is a large scale diverted water project from Datong river rises in Qinghai Province to Qingwangchuan basin that locates in north of Lanzhou city, Gansu Province. The project provided the source of water and changed water shortage situation of Yongdeng Xian, Gaolan Xian and Baiyin city. But the implementation of the diversion work fou irrigation is the main reason for changing the Qinwangchuan environment. On the one hand, irrigation water caused the change of water environment because of chemical composition variation in groundwater and salinization of soil. On the other hand, the low ratio of irrigation water resources utilization lead to water waste serious, and affected the development of economic and social of Qingwangchuan and surrounding areas.In the paper, based on collecting hydrological geology status, climate, hydrology, geology, physiognomy and the indoor experimenting, surveying the chemical variation of groundwater irrigation:TSD of groundwater has the trend of ascent that from 2.22g/L before irrigation up to 4.35g/L after irrigation. The hardness was inconsistent than the former irrigation. The content of Cl- and SO42- increased dramatically, K+、Na+、Ca2+、Mg2+ were growing slowly, and Mg2+ is less than K++Na+, NO3- increased comparison with before irrigation, CO32- is 0, HCO3- is less than Cl- and SO42-. Meanwhile, the paper analyzed the cause of environment change, and provided technical supporting for development of Qingwangchuan and surrounding area.The paper discussed the status quo of water resources development and utilization:the actual irrigated area is 2.81×104hm2 in 2009, accounts for 49% of original design, the amount of water is 2×108m3 in 2009, accounts for 45.1% of original design. The agricultural water accounts for 96.5% of the total amount of water, the ecological water accounts for 3%, the domestic water accounts for 0.5%. The paper bring forward many measures and advices for the usage of water resource such as (1) the development of new construction of Lanzhou. (2) to increase ecological water. (3) the development of storage functions of reservoirs. (4) the development of water-saving irrigation technique. (5) the development of efficient water-saving agriculture. (6) to strengthen the prevention of seepage of irrigation water. (7) to use some different water resources.. (8) to strengthen the management of irrigation water and enhance the efficiency of water resources.