民勤绿洲50余年水利建设的生态经济影响

民勤绿洲近50余年地表来水持续减少,为满足用水需求,兴修了一系列水利工程。以民勤县50余年的经济发展和生态环境数据为基础,从农业发展、产业结构调整以及生态环境要素的角度,运用图表对比分析研究区50余年内发生的生态和经济变化,进而研究了水利工程建设在这两方面所产生的影响。结论表明:在2012年来水量比水利工程建设前即1956年减少32.3%的背景下,水利工程建设支撑了民勤绿洲农业的发展;保证了3次产业结构向节水循环型方向调整,第一、二、三产业产值之比从1956年的14.9:3.2:1变成了2012年的1.2:1.1:1。但水利工程建设也对民勤的生态环境产生了负面影响,加剧了该区的地下水位下降及水质恶化、植被退化、土地沙漠化及盐碱化等生态问题。

Ecological and Economic Impacts of Water Conservancy Construction in Minqin Oasis of more than 50 years

In recent 50 years, the incoming surface water to Minqin Oasis has decreased continuously. In order to meet the demand for water resource, a series of water conservancy projects were built. Based on more than fifty years'economic and eco-environmental data of Minqin County, Gansu Province, China, ecological and economic changes happened during over 50 years in studied area were compared and analyzed through diagrams, from the perspectives of agricultural development, industrial structure adjustment and eco-environmental elements. Therefore, the two aspects of impacts of water conservancy engineering constructions on Minqin County were studied concurrently. Results show that:In the context that the incoming water in 2012 is 32.3% less than that in 1956, which is the year just before the construction of the above water conservancy projects, water conservancy constructions supported the development of agriculture in Minqin Oasis. Water conservancy projects also insured that the industrial structure changed towards the direction of water-saving recycling type, and the ratio of output value of primary industry to secondary industry to tertiary industry changed from 14.9:3.2:1 in 1956 to 1.2:1.1:1 in 2012. Water conservancy constructions, however, had negative impacts on the ecological environment of Minqin Oasis, and exacerbated the ecological problems including the falling of groundwater level, the deterioration of water quality, vegetation degradation, land desertification and salinization.