近20 a塔里木河下游输水对生态环境的影响

塔里木河下游是新疆生态环境问题比较突出的地区。为改善该地区恶化的生态环境，国家自2000年起向塔里木河下游实施了18次以生态建设和环境保护为目的的生态输水工程。近20 a来，塔里木河下游地下水位随输水次数增加呈不断上升趋势，生态植被不断修复，生态环境逐步好转。尤其是2017年实施第18次生态输水后，下输水量及其影响范围取得较大突破，引起社会高度关注。通过近20 a的断面来水监测资料，从水量、水质、地下水变化、植被恢复等方面，初步分析输水对生态环境的影响。同时，对前人研究的成果进行梳理和延展，使其对今后塔里木河下游的生态调度和科学管理起到指导作用。经分析得出以下结论：（1）虽然生态输水量基本都补给了生态植被和河道两侧的地下水，但持续性输水才是保证下游脆弱的生态环境稳定好转的根本途径。（2）输水使下游生态环境得到改善，现生态植被正在恢复，地下水位逐步抬升，地下水质明显好转。（3）采用汛期输水和间歇机动式调度，可使输水效益达到最大化。

Ecological effects of water conveyance on the lower reaches of Tarim River in recent twenty years

The ecological environment problems in the lower reaches of Tarim River in Xinjiang are very severe.To improve the local ecology and environment of the region,18 times of ecological water transports have been arranged in line with the principle of ecological construction and environment protection in the lower reaches of Tarim River since 2000.In recent twenty years,the ecology and environment has been progressively improved because the groundwater level has kept rising with the times of water transports and ecological vegetation restoration has kept going well.In particular,a real breakthrough was created in the lower reaches after water transport and its coverage after the 18th ecological water transports in 2017,which has got heightened attention from various circles of society.The paper analyzed the influence of water transport on the ecological environment in terms of water quantity,water quality,the change of underground water level and the vegetation restoration in accordance with the data of the river sections in the recent 20 years.Besides,a review of the previous researches was done,which will give a reference for the ecological operation and scientific management of the lower reaches of Tarim River.The results show as follows:(1) Through the transported water mainly feed the vegetation and groundwater along the two sides of the river course,the continual water transports are the firm guarantee for the steadily improvement of fragile ecology and environment of the lower reaches of the Tarim River. (2) Water transport has result in the ecology and environment betterment,vegetation restoration,groundwater table uplifting and groundwater quality improving. (3) Water transport at flood season or spasmodic and flexible arrangement for water transport could get the maximum benefit.