民勤人工绿洲的形成、演变及其可持续性探讨

民勤绿洲已经有2 000多年的历史,自20世纪50年代以来已经逐渐变为一个人工绿洲。目前民勤绿洲面临极大的危机,水资源减少是关键原因。水资源危机主要表现为地下水位下降和地表入境水量减少。同时,人口和经济发展的压力也持续加大。民勤绿洲退化的自然因素:①气候变暖;②蒸发强烈。人为因素:①农业开发是引起水资源相对减少的关键;②国营农场、林场加重了流域内水土资源的负担;③人工渠系的建成减少了水资源的无效消耗,但影响了地下水位的可持续供给能力,从而导致绿洲生态系统的退化。民勤绿洲的退化给人们以诸多的启示。解决民勤绿洲危机的措施:①确立"以保护水资源为中心"的指导思想;②撤销石羊河流域的国营农场、林场;③对农业用水实行累计进价管理;④调整产业结构,推广节水技术,种植低耗水的作物。

Study on Formation, Evolution and Sustainability of the Minqin Artificial Oasis

The history of the Minqin Oasis has been more than 2000 years,and the oasis has become as an artifi-cial oasis since the 1950s.Currently,there are some serious crises in the Minqin Oasis,such as the reduction of water resources,serious drawdown of groundwater level and decrease of inflow entering Minqin County,and the shortage of water resources becomes more and more serious along with population growth and economic development.Degeneration of the Minqin Oasis is caused by both natural and artificial factors,such as climate warming,shortage of water resources,violentevaporation in deserts,agricultural and forestry development (especially in state farms and forestry centers),and ineffective water loss from the irrigation works.Degeneration of the Minqin oasis gives us a lot of enlightenments.Therefore,it is suggested to pay great attention to conserving water resources,abolish the state farms and forestry centers in the middle and lower reaches of the Shiyang River Basin,improve the management of irrigation water,readjust the industrial structure,popularize the water-saving farming techniques,and plant the crops with lowwater consumption.