石羊河流域水资源及生态环境变化特征分析

针对石羊河流域水环境持续恶化的态势,调查分析了流域内水文和水化学环境变化的特征以及滥用水资源对生态环境的影响,表明石羊河流域水环境恶化的主要原因是水资源滥用.各类人工输水工程的建设改变了流域内水循环格局,导致下游河道断流,地下水补给量和泉水量减少;地下水持续超采,水位大幅度下降,矿化度升高,土地盐碱化面积迅速扩大,下游地区生态环境严重恶化.所以石羊河佑流域的综合治理必须以"水"为核心,地表水资源统一调度.并向下游倾斜;严格限制地下水开采量,使其逐年恢复到生态水位;发展节水农业,使大量水资源用于生态恢复;采取生物措施治碱,达到改良盐碱土、提高植被覆盖率和减少沙尘的功效;科学管理和调度水资源,建立人水和谐关系,保证区域内生态恢复和社会经济可持续发展.

Analysis on the characteristic changes of the eco-environment and water resources in Shiyang River Catchments

The present paper intends to report our investigation and analysis over the characteristic changes of the eco-environment and water resources in Shiyang River Catchments in the eastern Hexi Corrldor. Gansu. Our investigation has disclosed that serious chanes have taken place over the past 50 years since 1950s, and, in term, eco-environment and water supply features have been negatively influenced, such as over-exploitation of the surface-running water, the shrinking groundwater replenishment in the lower reaches as well as tile decreased spring water supply. In our investigation and analysis, we have found that over-exploitation of the groundwater and large- scale water-irrigation system development have virtually resulted in lhe serious consequences in the water resource distribution pattern in the catchmets; and serious eco-environmental problems have in turn been brought about in recent years. In particular, the groundwater balance and tile normal relationship between the water resources and tile eco-envirnnment have seriously been disturbed. As a result, the rate of mineral content in the ground water goes up with the Saline-alkali I iTicreased and the decertified soil spreading. In hoping to stop such a tendency, it is suggested in our paper to strengthen the scienific use of the local water resources as well as the proper groundwater exploitation so as to restore the original beautiful natural eco-environment and ensure the sustainable development of the regional economy.