泾河张家山水文站水沙特性分析及工程实例

Analysis on characteristics of runoff and sediment of Zhangjiashan hydrological station and case study for Jinghe river

为合理评价和利用多沙河流水资源,基于张家山水文站1956年-2009年逐日降水量、径流量、输沙量和含沙量数据,分析张家山站水沙变化特征。各系列多年平均特征值表明:输沙量不均匀系数最大,7、8月输沙量占全年的81%;降水、径流主要集中在7-9月。统计年降水量、径流量、输沙量和含沙量分期年平均特征值,前三者时段均值呈减小趋势,含沙量时段均值波动变化。Mann-kendall秩次相关检验显示年降水量、径流量和输沙量的检验值分别为2.39、4.45、3.36,都大于0.05的置信水平,均有显著减小变化趋势。输沙模数时段均值减小,来沙系数时段均值增大。灰色相关度和双累积曲线分析表明:径流与输沙量、降水量相关性较好,径流与输沙量关联度为0.64,比径流与降水的关联度0.62稍大。最后,探讨泾恵渠渠首排沙闸工程,泾恵渠引水合理沙限为15%,排沙闸适宜排沙流量为200m3/s。研究结果可为泾惠渠渠首改建工程设计提供参考。

For reasonable evaluation and use of water resources of sediment-laden river, based on precipitation, runoff, sediment discharge and concentration data of Zhangjiashan Hydrological Station from 1956 to 2009, this paper analyses the variations of runoff and sediment of Zhangjiashan Station. The average characteristic value for many years of each series show that uniformity coefficient of sediment discharge is the largest, sediment discharge in July and August accounts for 81% of the annual total; Precipitation, runoff mainly concentrate in July and September. Statistics of annual average eigenvalue for sub-periods of precipitation, runoff, sediment discharge and concentration are given. The first three items are all in a decreasing trend, the average for sub-periods of sediment concentration fluctuates. Mann-kendall rank correlation test results show that test U-values of annual precipitation, runoff and sediment discharge are ？2.39, ？4.45, ？3.36, all greater than 0.05 confidence level, which indicates that each has significant decrease trend. Period mean of sediment transport modulus reduces, period mean of incoming sediment coefficient increases. Grey correlation analysis and double cumulative curve show runoff and sediment discharge, precipitation all have good correlations, the association degree of the runoff and sediment load is 0.64, slightly larger than that of the runoff and precipitation of 0.62. Finally, this paper discusses the sediment gate project of the headworks in Jinghui irrigation district. The conclusion is that the reasonable limit of sediment is 15%, and the suitable sand excretion flow is 200 m3/s. The results can provide a reference for water project design of headworks of Jinghui irrigation district.