长江上游流域径流年内分配特征分析

根据长江上游主要测站径流资料,分析了年内分配不均匀系数、集中度和集中期、变化幅度等特性。分析站点包括金沙江屏山站、岷江高场站、嘉陵江北碚站、长江上游干流寸滩站及乌江武隆站。结果表明:北碚站的不均匀性要大于其它站点;北碚站集中性最大,而武隆站最小;武隆站的径流集中期大部分为6月下旬,其它站集中期在7—8月;北碚站的相对变化幅度要大于其它站点,而屏山站最小。进一步应用Kendall秩次相关法分析各站的径流年内分配特征年际变化情况,发现高场站的不均匀性系数、集中度、相对变化幅度存在明显减少趋势。

Changes of Annual Runoff Distribution in Upper Streams of Yangtze River Basin

In this paper,indexes of concentration,concentration period,unevenness and variation have been defined and calculated according to gauge records of runoff at the main station in the upper streams of the Yangtze River Basin.The main stations include the Pingshan Station on the Jinsha River,the Gaochang Station on the Minjiang River,the Beibei Station on the Jialing River,the Cuntan Station on the upper Yangtze River and the Wulong Station on the Wujiang River.And then the changes of annual runoff distribution in the upper streams of the Yangtze River Basin have been discussed.The results show that the unevenness of Beibei Station is greater than the other stations;the concentration unevenness of Beibei Station is the greatest and Wulong Station is the smallest.The concentration period of Wulong Station is in late June and in the other station is in July or August.The relative variation rate of Beibei Station is the greatest and Pinshan Station is the smallest.The inter-annual changes of annual runoff distribution were further analysed by the Kendall’s rank correlation method.The results show that the unevenness,concentration and relative variation rate decreased obviously.The conclusions are meaningful for water resources management in the upper streams of the Yangtze River Basin.