中国西部生态系统的水问题综合评估研究——以三工河流域为例

基于中国西部生态系统综合评估的概念框架,提出了该评估的水问题评估目标和概念框架,并以三工河流域为研究对象,通过对不同年份生态系统服务价值的评估,以人工生态系统和天然生态系统服务功能最大化为原则,确定1987年的生态景观状态组合为生态系统保护的最佳生态目标。在此保护目标下,分别估算了河流廊道和河道外生态需水,判定三工河流域生态需水的阈值区间为17%～24%。其后,结合社会经济需水的预测情况,综合分析了当地居民福利变化的情况,并以河流廊道用水和河道外用水平衡、社会经济内部用水平衡以及生态系统和社会经济系统用水平衡为原则,提出了基于人与生态和谐的水资源配置的对策和建议。

Study on Integrated Assessment of Water Problems in the Ecosystem of Western China-Taking Songong River Basin as a Case

The paper includes assessment of ecological and socio-economic water requirements and measures of water resources allocation.Firstly,the conception framework and targets of Integ-rated Ecosystem Assessment of Western China (MAWEC),which is a sub-global assessment project of Millennium Ecosystem Assessment (MA),have been proposed. In the case study of the Sangong River Basin,changes and the corresponding driving forces of aquatic ecosystem services function have been investigated.The results showed that human activities, especially land use change, had great impacts on the ecosystem,while the ecological impacts of natural forces were quite uncertain.Secondly,ecological water demand of river corridor and off-stream ecosystem have been carried out as following:(1) eco-hydrological zoning in the Sangong River Basin;(2) defining the key region of ecological water demand on the basis of characters of natural and man-made ecosystems in the oasis region;and (3) setting the favorite ecological protect-ion objects according to annual ecological services function assessment and maximum principle of total service function from natural and manmade ecosystems.The results showed that the ecological station of 1987 was the most favorite one for ecological protection and,total ecological water demand of the protection object accounted for 24% of surface water resources in the region,where the ratio between river corridor and off-stream ecological water demand was 2.5:1.Thirdly,socio-economic water demand was projected.Finally,according to changes of resident welfare,countermeasures of water resources allocation has been proposed taking into account water bal-ance between river corridor and off-stream,water balance among socio-economic system,water balance between ecosystem and socio-economic system.