珠江流域主要河流泥沙变化分析

选用珠江流域主要河流的58个泥沙站1956～2000年连续观测的泥沙资料,按河流水系分不同的区域对主要河流含沙量和河流输沙量的时空分布规律进行分析研究。结果表明:大多数河流的含沙量较小,由于径流量大,输沙量较大;含沙量在区域上的分布呈西部大于东部、西南部大于西北部,东南部与东北部差别不大的特征;主要河流西江、北江、东江含沙量沿程变化呈现从上游往下游递减的规律;产沙量最大的区域是南盘江和北盘江,西江上游区域是流域泥沙的主要来源;汛期输沙量占全年的90%以上。虽然各区域不同时期输沙量有所增减,但全流域输沙总量较稳定;西江上游红水河和东江水利工程的兴建对河流泥沙的拦蓄明显,造成下游河段的含沙量明显减小。

Study on Variation of Main Rivers Sediment in Pearl River Basin

Base on the continuous observed sediment data from 58 sediment stations of the main rivers in the Pearl River Basin from 1956 to 2000, the sediment concentration and sediment runoff of the main rivers in the temporal and spatial distribution for hydrographic net in different areas were studied. The results show that the majority of sediment concentration of the rivers are small, due to the runoff, sediment runoff are larger; sediment concentration in the spatial distribution is greater in the west than that in the east, and greater in the southwest than that in the northwest, without large difference between southeast and northeast. The sediment present diminishing variation from upstream to downstream along the main rivers of Xijiang, Beijiangr and Dongjiang. The rivers of Nanpanjiang and Beipanjiang are the largest areas of sediment yield, and the upper reach of the Xijiang River is the main source of the sediment. Flood sediment accounted for more than 90%. Although the sediment runoff increased or decreased in various areas during different periods, the total sediment transport capacity is stable. The water structures in the upper reaches of the Xijiang River and Dongjiang River retain the sediment significantly, leading to significant reduce of sediment concentration in the downstream.