关键词: 水环境问题; 高效节水生态农业; 面源污染; 生态调蓄带; 外流域补水; 洱海流域;

Abstract: Erhai Lake is a main drinking water source of the Bai ethnicity in Dali, Yunnan Province.There are some water environmental problems in Erhai Lake, such as the complicated evolution process of water quality, the difficulty to effectively control non-point source pollution, the aggravation of water resource shortage, and the slow natural recovery of submerged plants along the lakeside.According to the new thinking on water conservancy in the new era, this paper puts forward some targeted measures, such as facilitating the development of efficient water-saving agriculture, strengthening the end interception of pollutants by the ecological storage zones, carrying out projects to supplement water from other river basins, and optimizing the water level scheduling of Erhai Lake from April to July, which are keys to achieve Erhai Lake′s sustainable improvement of water quality and water ecosystem as well.Therefore, this paper established amathematical model of water environment of Erhai Lake to carry out the numerical simulation of water quality improving measures.The results showed that the efficient water-saving agriculture could reduce more than 30% of the pollution loads from the source.The rain sewage in the confluence area during the dry season and the early rainfall period could all be intercepted and reused by the ecological storage zones.The water supplementation from other basins can make up the shortcoming of water resource shortage, to improve annual water quality of Erhai Lake by 1.29%～5.15%,which can provide a good water resources condition support for the optimal scheduling of water level and water ecological restoration in Erhai Lake.

Key words: water environmental problems; efficient water-saving ecological agriculture; non-point pollutant; ecological storage zones; water supplementation from other basins; Erhai Lake Basin;