Evaluation On Water Resources Amount Of Shiyang River Basin And Forecast Its Application Based On Ecological Water Demand

Environment in Shiyang River Basin was highly emphasized by China government and the implemented comprehensive management projects have shown significant effects. The management projects considered the demand of life, ecology, industry and agriculture made full use of water saving measures, and distributed the water based on the year of 2003. However, with the economic and social development, water demand has increased greatly and the current water resources can not satisfy the need, especially for the ecological demand. To strengthen the water resources management, protect environment and solidify the current management results, this paper did the following research based on the current situation and hydro-geological data. The components of surface water, groundwater and ecological water demand were analyzed and the runoff volume for the main and branches of Shiyang river was calculated. In addition, the surface water in shallow mountain area was also taken into consideration. The groundwater in Wuwei basin, Minqin Basin, Yongchang Basin, Changning Basin and Chaoshui Basin was analyzed. The ecological water demand for the whole Shiyang River Basin was also analyzed. Based on the water balance, hydrological equations for surface water and groundwater, and ecological water demand equations, the following results were drawn:(1) Based on the current condition, and considering impact of climate on surface water, water transfer from other basins and groundwater exploitation, the available surface water in Shiyang River Basin was 23.19×108m3, while the groundwater was 6.79×108m3.(2) Ecological water demand includes natural vegetation and artificial vegetation demand. Since the groundwater table has exceeded the critical groundwater table, the natural water demand can be ignored. Except the artificial forest and grass water demand, which have been included in the agricultural irrigation, the artificial ecological water demand, which is artificial lake ecological water requirement, has a minimum of 1.236×108m3.(3) Aiming at the contradiction of ecology and society development, the solutions of guaranteeing ecology and life and taking using water efficiently into consideration were put forward. The water demand in 2030 was forecasted and distributed,the high value is 28.75 hundred million m3,moderate value is 24.42 hundred million m3,low value is23.3 hundred million m3.