近50年来河西走廊地下水资源变化及对生态环境的影响

利用不同时期出山地表水资源和相应的地下水均衡计算结果,分析对比了近50年来河西走廊地下水资源变化特征。结果表明,自20世纪50年代以来,出山地表水资源年际变化相对比较稳定。与此同时,随着中游地区工农业生产的持续发展和水利化程度的日臻完善,地下水补给量逐步减少,由1955年的62.413×108m3减少到1999年的55.514×108m3,减少了6.899×108m3。由此引起了区域性地下水位持续下降、泉水资源大幅度削减、地下水开采规模和开采量逐年扩大、进入下游的地表水不断减少、水质恶化等水文地质问题。伴随着水资源利用分布格局的改变,河西走廊生态环境体系不断演变并趋于恶化。

Changes of groundwater resources in recent 50 years and their impact on ecological environment in Hexi Corridor

The changing features of groundwater resources in recent 50years have been anal-ysed and compared by using calculated results based on surface water from mountain area s and their corresponding groundwater balance during different period of time in Hexi Corridor.The result shows that the annual surface water resources from mountains are relative stable,mean-while the recharges of groundwater are decreasing successively because of industrial and agri-cultural development and ir rigation system in the middle reaches becoming better and approach-ing perfection day by day since the1950s.The groundwater recharge decreased from62.413×10 8 m 3 in1955to55.514×10 8 m 3 in1999.As a result,a se ries of hydrogeological problems,such as constant decline of regional groundwater level,substantial reduce of spring water,yearly en-largement both in scale and amount of groundwater extraction,continuous decrease of surface water entering into the lower reaches,water quality worsening and so on.The eco-environmental system tends to change and becomes deteriorated with the changes of water resources in utiliza-tion and distribution patterns.