中文摘要：

通过对1960~2010年西江流域主要水文控制站梧州站和高要站长时序水沙数据的全面分析,深入探讨了西江水沙的变化特征.结果表明：在1990年代初之前,西江年径流量变化不明显,之后,呈明显下降趋势,降水量减少是西江年径流量减少的主要原因;西江输沙量变化较大,在1983年以前呈微弱上升趋势,到1983年达到峰值,而在1983年以后,西江流域悬沙呈显著下降趋势;1950年代以后大炼钢铁活动和大力发展农业导致大面积树木砍伐,水土流失加剧,造成河道输沙量增加;1983年以后,以植树造林为主的水土保持措施和水土保持法规制定,加上大量水利工程建成使用,造成西江流域下游悬沙量减少;1990年代初期以后,悬沙量减少幅度远大于径流下降幅度,说明悬沙变化除受径流变化影响以外,还受水土保持措施、水利工程建设等人类活动的影响.

英文摘要：

Based on the water and sediment load data from 1960 to 2010of the major hydrological control station（Wuzhou station and Gaoyao station）of the West River basin,we systematically analyzed the changing trend of the water and sediment load of Western River.The results indicate that the change of the flow discharge of the Western River is not obvious from 1960 to 1990s.However,the trend of flow discharge decreased apparently since 1990 s.The main reasons causing this decrease was that the precipitation of the upriver area reduced in the Pearl River;Compared with the flow discharge,the change of the sediment load of Western River was huge.Before 1983,the amount of the sediment load was increasing slightly.After 1983,the amount of the sediment load dropped significantly,The reason causing the increase before 1983 was that there were water and soil erosion,which was caused by excessive tree felling led by steel production and land clearing;After 1983,because the measures and laws of the conservation of the water and soil began,the amount of sediment load decreased.Besides,the massive building of water reservoirs also played an important role in it.Statistical results show that the trend of decrease of sediment load was much larger than the trend of decrease of flow discharge since 1990 s.It shows that the sediment load was not only affected by the flow discharge,but also some other factors,such as the strength of the conservation of the water and soil and the building of water project.