螺山站水位变化特征及其影响因素贡献率分析

Analysis of Variation Characteristics of Water Level at Luoshan Station and Its Contribution of Influencing Factors

为分析螺山站水位变化特征及其影响因素贡献率,采用回归分析、Mann-kendall检验等方法分析螺山站1954~2013年的水位、流量变化规律。结果表明,螺山站水位于1954~1964、2003~2013年呈减小趋势,1965~2002年呈增加趋势,且分别于1977~1979、2004年发生突变。1981~2002年较1967~1980年,1~3月份流量的改变对螺山站水位变化的贡献率分别为38.7%、33.5%、55.2%,河床冲淤及顶托作用的贡献率分别为61.3%、66.5%、44.8%。下荆江裁弯使得螺山站的水位抬升了1.98m,葛洲坝和三峡水库的运行使其水位分别下降了0.92、0.26m。下荆江裁弯、葛洲坝和三峡水库的运行对螺山站水位变化的贡献率分别为63.6%、28.1%、55.4%。研究成果可为长江中下游河道的防洪预报与调度提供参考。

The linear regression method and Mann-kendall trend test were adopted to analyze the variation characteristics and influencing factors of water level and discharge at Luoshan Station from 1954 to 2013.The results show that the water level declined from 1954 to 1964and from 2003 to 2013,while rose from 1965 to 2002,with two sudden change points during 1977-1979 and in 2004.Compared with the data from 1967 to 1980,during 1981-2002,the contribution rates of flow change to the water level from January to March were 38.7%,33.5% and 55.2% respectively;meanwhile the contribution rates of riverbed scouring and siltation and backwater effect were 61.3%,66.5% and 44.8%,respectively.Cut bends of lower Jingjiang made the water level rise by 1.98 m while the operation of Gezhouba and Three Gorges Reservoir made the water level decrease by 0.92 mand 0.26 m,respectively.The contribution rates of the cut bends of lower Jingjiang,the operation of Gezhouba and Three Gorges Reservoir to the water level were 63.6%,28.1% and55.4%,respectively.The results provide reference for flood forecasting and dispatching along the middle and lower reaches of the Yangtze river.