SAFETY ANALYSIS OF WATER RESOURCES AND ECO-ENVIRONMENT IN SHIYANG RIVER BASIN

The research on the present situation of soil and water development and utilization in Shiyang River Basin shows that water resources and eco-environment situation in this area are near the edge of collapse. Since the water crises occurred in the 1970s, problems caused by continuous decrease of water resources have been becoming serious year by year and eco-environment crisis occurred as a consequence. Up to now, 10 380ha of irrigated lands have been abandoned due to sand coverage and water shortage in the basin. Ground water was over exploded in Wuwei and Minqin because of water shortage. Ground water table in many places dropped under 5m ( which is the ecology water table level), thus about 3000ha of Elaeagnus angustifolia forest come to dead and another 5800ha become feeble, and wind-drift sand near the oasis become alive. According to the current situation, if water utilization scope was not enlarged, a water transfer volume of 600x10(6)m(3)/a from other areas will be suitable to keep water resources and eco-environment safety in the basin, and also 70x10(6)m(3)/a will be left as spare water. Under this condition the water resources and eco-environment of the basin can reach the critical safety line of 2.032x10(9)m(3)/a; or if 180x10(6)m(3) of water can be transferred from other areas, the water resources can reach the safety warning line of 1.732x10(9)m(3)/a.