新疆奇台县坎儿井废弃过程及其驱动力分析

Study on Abandoned Process and Driving Forces of Karez in Qitai of Xinjiang

对奇台县坎儿井分布状况、兴衰过程、地质情况、地下水位实地调查和其社会经济的资料分析表明,奇台县坎儿井经历了从1949年开挖,20世纪60年代初数量达到最多,20世纪80年代初期全部废弃的一个由兴到衰的过程。人口增加和农业生产的发展是导致地下水位迅速下降、坎儿井干枯的根本原因。坎儿井数量变化过程与人口、耕地增加过程早期基本一致,后期变化方向相反。人口数量达到90 000人,水浇地为50 000 hm2时,平均地下水埋深为5 m左右,坎儿井开始衰亡。坎儿井全部废弃时平均地下水位约深8 m,此时,人均地下水可开采量仅1 300 m3,农田灌溉所用地下水已接近地下水可开采量。后期河流引水量和地下水开采增加的量大于降水量及河流来水量对地下水的补给量,地下水位仍不断下降,坎儿井没有恢复,反映人文因素对地下水的影响程度远远超过自然因素。

The survey of Karez in Qitai county, including the distribution, depth, length, direction, distance between wells, geology, water lever, the process of rise and decline, and analysis of social economic data, indicate that Karez in Qitai county were begun to dig from 1949, at 1960＂s the amount of Karez reach the most, at early 1980＂s, all the Karez were abandoned. This change is caused by excessively use groundwater and make groundwater level declined. While the basic reason of groundwater level decline is population in- creasing and agriculture development. The trend of quantity change of Karez is contrary to that of the population and ploughland. When population reached 90 000 and irrigable land was 50 000 ha, average groundwater level was about 5 m, Karez began to decline. The average groundwater level was about 8 m when all the Karez had been abandoned, and exploitable quantity of groundwater per person only was 1 300 m^2 , agricultural irrigation water was almost equal to the exploitable quantity of groundwater