西江流域干流近年水沙变化特征

Characteristics of water and sediment variation of main streams in Xijiang River basin in recent years

选取西江干流迁江站、大湟江口站、梧州站、高要站1957-2016年的年径流量与年输沙量数据,采用Mann-Kendall检验法、5年滑动检验法、累积距平法进行定量与定性分析,同时使用模拟退火算法进行非线性回归分析,得出西江流域干流年径流量和年输沙量的变化规律。结果表明:径流量与输沙量年内分配具有一定不均匀性;迁江站的径流量和输沙量呈显著下降趋势,其他站的年径流量变化呈上升趋势、年输沙量呈显著下降趋势。迁江站径流量于2002年发生突变。迁江站、大湟江口站、梧州站和高要站年输沙量分别在1991、1997、1994、1999年产生显著突变。西江干流年径流量变化趋势呈微波动,年际变动幅度较小,年输沙量呈下降趋势,突变点为1990年。

This paper selects the annual runoff and annual sediment transport data of Qianjiang station,Dajingjiangkou station,Wuzhou station,and Gaoyao station from 1957 to 2016 in the mainstreams of Xijiang River,applies Mann-Kendall test,5-year sliding test,cumulative anomaly methods to carry out quantitative and qualitative analysis,uses the simulated annealing algorithm for nonlinear regression analysis at the same time,and obtains the changes of annual runoff and annual sediment transport.The results show that the distribution of runoff and sediment transport volume is uneven throughout the year.The runoff and sediment transport volume of Qianjiang station are significantly decreasing.The annual runoff volume of other stations is increasing,and the annual sediment transport volume is significantly changing decline.The runoff at Qianjiang station changs abruptly in 2002.The annual sediment transport volumes in Qianjiang,Dahuangjiang Estuary,Wuzhou and Gaoyao stations have significant mutations in 1991,1997,1994,and 1999 respectively.The annual runoff variation trend shows slight fluctuations,the annual variation range is small,and the annual sediment transport volume shows a downward trend.