宜昌站泄流能力变化对葛洲坝设计洪水影响

Analysis on influence of discharge capacity variation at Yichang station on the design flood of Gezhouba project

宜昌水文站是葛洲坝、三峡水利枢纽的设计依据站。葛洲坝水利枢纽动工修建和运行 ,对该站水位流量关系中低水部分产生了影响。探讨了该河段泄流能力的变化对葛洲坝水利枢纽设计洪水有无影响的问题。用1 967～ 1 999年实测资料对宜昌站以汛期平均水位为参数的水位流量关系曲线簇进行了检验 ,大部分年份最大日平均流量、3、7、1 5、30d洪量的偏差在± 4 %之间 ,说明曲线簇推流具有相当的精度。

Yichang hydrologic station provides design data for Gezhouba project and Three Gorges project. The construction and operation of Gezhouba hydroproject brought impact on the stage discharge relation during medium and low water period. Whether the variations of discharge capacity of this reach influences the design flood of the Gezhouba hydroproject was analysed. According to the measured data during the period of 1967～1998, the stage-discharge hydrographs at Yichang station, taking the average water level in flood period as parameter, were checked. The error of the maximum daily average discharge, 3,7, 15, 30-day flood volume in most years are within ±4%, demonstrating the computed discharges based on the hydrograph possess considerable accuracy. The analysis results demonstrate the variation of discharge capacity of Yichang reach in medium and low water period have no influence fundamentally on the design and check flood discharge of Gezhouba hydroproject.