塔里木河流域近50年来生态环境变化的驱动力分析

结合塔里木河流域近50年来水文、植被以及社会经济等方面的资料．采用趋势分析方法估算人为因素对流域地表径流的影响．通过相关和主成分分析等数学方法分析人类活动诸因子与流域地表径流和地下水质之间的关系。研究结果表明．塔里木河上游源流区的地表径流在过去的几十年里没有减少．且有一定程度的增加，塔里木河干流地表径流量减少是人类活动所致；人类活动在1970、1980和1990年代对流域上中游地表径流的影响量分别为41．59％、63．77％和75．15％；由人类活动所导致的地表径流量减少是影响河道水质发生变化的主导因子，而地下水位变化则影响灌区和非灌区地下水水质；塔里木河下游生态系统受损与人类活动直接相关。

The Driving Forces of Environmental Change during the Last 50 Years in the Tarim River Basin

Based on the data of hydrology, vegetation and socio-economy during the last 50 years in the Tarim River Basin, this paper estimated the impact of anthropogenic activities on surface runoff through trend analysis, and measured the relationship between factorsof anthropogenic activities and surface runoff and groundwater quality by correlation analysis and principal component analysis. The results showed that during the past 50 years the headstream's runoff didn't decrease but increased and the mainstream's runoff decreased due to anthropogenic activities. The proportions of impact of anthropogenic activities on the mainstream's runoff are 41.59%, 63.77% and 75.15% respectively during the 1970s, 1980s and 1990s. The main factor that affects water quality in the watercourse is the decreasing surface runoff induced by anthropogenic activities, and the main factor that affects water quality in irrigated and non-irrigated areas is groundwater level. In fact the ecosystem's degeneration in the lower reaches of the Tarim River is directly correlated with anthropogenic activities.