天山南坡季节河流——黄水沟生态流量阈值分析

Analysis of Ecological Flow Threshold of Seasonal River—Huangshuigou in the Southern Slope of the Tianshan Mountains

科学确定内陆河流生态流量阈值是保障干旱区水生态安全和生态环境健康的重要基础。基于1980~2020年实测径流资料,采用水文学多种方法,对新疆开都河流域黄水沟的生态流量和下游生态水量阈值分河段进行分析显示,作为典型的干旱区山溪性季节河流,黄水沟山区段为长流水河段,应保障其生态基流以保护山区水生态;出山口以下季节性河段依据生态保护目标科学确定适宜生态水量更为合理。基于Qp法确定的黄水沟水文站断面的年内丰水期(5~10月)生态流量为3.90 m3/s,年内枯水期(11月~翌年4月)生态流量2.46 m3/s;结合黄水沟水文站至入博斯腾湖河段多年平均河损,以及黄水沟防洪和黄水沟下游生态环境保育需求,计算分析确定入博斯腾湖南大闸断面年内丰水期多年平均最小入湖生态水量为0.20亿m3。

It is an important basis to scientifically determine the ecological instream flow of inland rivers for ensur-ing water-ecological security and eco-environmental health in arid areas. Based on the measured runoff data from 1980 to 2020, the ecological instream flow and the downstream basic ecological water require-ment of the Huangshuigou River in the Kaidu River Basin of Xinjiang were analyzed by various hydrologi-cal methods. As a typical seasonal mountainous river in arid area, mountainous section of Huangshuigou River upstream is a long-flowing river section, and its ecological base flow should be guaranteed to protect the upstream water ecology. It is more reasonable to scientifically determine the basic ecological water requirement according to the goal of ecological protection in the seasonal lower reaches. Based on the QP method, the ecological instream flow of the upstream section at Huangshuigou hydrological station is 3.90 m3/s during the flood season of the year (May-October) and 2.46 m3/s in the dry season (November-April) of the year. Considering the average annual river loss from the Huangshuigou hydrological station to the section of the river flows into the Bosten Lake, as well as the flood control safety and the ecological and en-vironmental conservation needs of the lower reaches of the river, the average annual minimum ecological water volume in the flood season is not less than 0.20 billion m3.