梯级水电站对黑河出山口径流及洪水过程的影响

基于莺落峡水文站的月年径流量、年最大洪峰流量、洪水过程及黑河上游流域降水等资料,运用双累积曲线法、Mann-Kendall趋势检验法(简称MK检验法)、基尼系数法等方法,分析梯级水电站对黑河出山口莺落峡水文站径流及洪水过程的影响。结果表明:黑河上游梯级水电站的建设运行对年径流量变化影响不大,对径流年内分配及洪水过程有一定影响;电站联合调度运行后,坝前库区蓄放水改变了天然径流过程,对径流年内分配产生显著影响,年内分配均匀度在2001年发生转折,2017—2020年呈显著增加趋势;人为升降闸门高度,致使水位直上、直下,洪水过程拉长,峰值变大,呈陡涨直落形态,涨落率和变化频次增加。研究成果可为加强流域水电站科学调度、水生态文明建设及水能水资源可持续开发利用提供理论依据。

Impacts of Cascade Hydropower Stations on Runoff and Flood Process at Mountain Exit of Heihe River

The influence of cascade hydropower stations on the runoff and flood process of Yingluoxia hydrological station at the outlet of Heihe River is analyzed by using the double cumulative curve method, MK test method and Gini coefficient method based on the monthly annual runoff, annual maximum peak discharge, flood process of Yingluoxia hydrological station and precipitation in the upper reaches of the Heihe River.Results demonstrate that the construction and operation of cascade hydropower stations in the upper reaches of Heihe River has no large impact on the change of annual runoff, but has a certain impact on the annual distribution of runoff and flood process.After the joint dispatching and operation of the power stations, the regulation and storage of the reservoir in front of the dam has changed the natural runoff process and has a significant impact on the annual distribution of runoff.The annual distribution uniformity showed a transition in 2001 and a significant increasing trend from 2017 to 2020.The artificial rising and lowering of the gate resulted in the straight rising and falling of water level, the elongation of flood process, the expansion of peak flood in the form of steep rise and fall, and the increment of the rise and fall rate and change frequency.The research findings offer theoretical basis for strengthening the scientific operation of hydropower stations, the construction of water ecological civilization and the sustainable development and utilization of hydropower and water resources.