长江螺山汉口大通三站水位流量关系历年变化分析

Variation of the stage—discharge curves over years at three Yangtze hydrologic stations

根据长江中下游干流主要控制站螺山、汉口、大通等三个站1950年～1988年共39年实测断面和流量资料,分析该三站水文断面年内及年际冲淤变化规律,并运用水位流量关系单值化技术,分析以上三站50～80年代同流量同比降下水位变化趋势及其同水位下泄洪能力的变化。分析表明,螺汉两站同流量水位低、中水均有不同程度的抬高,高水变化甚小;同水位流量低、中水呈减小趋势,高水尚无明显趋势变化。大通站高、中、低水均无大的变化。

Based on really surveyed profiles of hydrologie sections and recorded data of discharge at three major Yangtze hydrologic stations,Luoshan,Hankou and Datong,of the middle—lower Yangtze river,during 1950 to 1988,the behaviour of these profiles variation as well as the stage—discharge curves variation caused by erosion and sediment deposition within a year or over years have been studied; and by means of the averaging technique for stage—discharge relation,the variation trend of stage under the same discharge and gradient of water surface conditions,and the variation of flood discharge capacity under the same stage condition have been studied The research results indicate that with Luoshan and Hankou stations,the values of stage under the same discharge condition during medial and low water all rise to a certain extent year after year,and only a little variation of stage occurs during high water,and that values of discharge under the same stage condition during medial and low water all decrease year after year,and there is no obvious variation of discharge during high water;and that with Datong station,either values of stage under the same discharge condition or values of discharge under the same stage condition during high,medial and low water all have no obvious variation.