塔里木河流域水量变化对生态环境影响分析

本文以塔里木河流域的10个水文站1961~2000年观测资料为基础,对塔里木河流域的径流变化及其对下游生态环境影响进行了分析。分析得出:(1)20世纪60年代以来,塔里木河各源流的出山口径流量增加23.82×108m3,增幅达14.97%,但是,能汇入塔里木河干流的水量并没有增加,而且比60年代减少了8.8×108m3,减幅达17.41%。(2)近40年以来,由于塔里木河干流上中游地区的耕地面积急剧扩大,用水量剧增,使下游的来水量比60年代减少7.72×108m3,减幅达76.13%。(3)由于塔里木河上中游耗水量的增加,塔里木河下游来水量逐年减少以至断流,由此造成下游生态环境出现较大的变化,主要表现有:河水盐化严重,灾害性天气出现的次数大幅增加,河道断流,地下水位下降,天然植被严重衰败,沙漠化过程加重。(4)实施塔里木河流域水资源的统一管理,统筹分配上、中、下游水量,调整大农业生产方向,完善流域节水改造配套工程,发展节水型农业,是塔里木河下游受损生态环境恢复与重建的关键。

Influence of Runoff Variation on Ecological Environment in the Tarim River Basin

Based on observations of 21 meteorological stations and 10 hydrological stations in the Tarim River Basin,the changes of temperature,precipitation and runoff from 1961 to 2000 were analyzed.Four conclusions were drawn as follows:(1) The runoff of the headstreams at their debouchures increased by 14.97% since the 1960s,whereas the total discharge into the Tarim mainstream decreased by 17.41% at the same time.(2) Water in lower reaches decreased by 76.13% in recent 40 years,and the reduction of water was closely related to the rapid exploitation of the agricultural area and the sharp use of the water resources in the upper and middle reaches.(3) Owing to the increasing water requirement of the upper and middle reaches,the lower reaches' inflow was decreasing year by year.Therefore,the environment in the lower reaches changed greatly,mainly showed as serious water salinization,increasing of disaster weathers,frequent zero-flow,declining of groundwater table,decreasing of forest and aggravating of desertification.(4) The unified management of water resources in this basin is the foundation of ecological rehabilitation and reconstruction.