珠江三角洲干流汊道泥沙分配及变化--以西、北江三角洲为例

通过对６０年代和９０年代珠江三角洲河网典型汊河泥沙分配变化的对比分析，认为（１）珠江河口区的泥沙主要来自陆相径流挟带的下行泥沙和随潮流挟带的上溯泥沙，其中径流及其挟带的泥沙是现代珠江三角洲建造过程中的基本动力和物质，起着主导作用，而珠江河口区由径流挟带的悬移质泥沙又主要来自西江。（２）西北江干沙处于逐年淤积的总趋势，其中河流段冲淤变化不大，过渡段有冲有淤，以淤为主，潮流段由是普遍淤积。（４）海平面

ALLOCATION AND VARIATION OF SEDIMENT FOR BRANCHING CHANNELS OF MAIN RIVER IN THE PEARL RIVER DELTA--A Case Study of the West and North River Delta

The allocation rate of sediment discharge for typical branching channels in the West and North River Delta was calculated, and the variation features of sediment was analyzed. Some conclusions were obtained: 1) With a small part being transported by tide, the sediment in the estuary of the Pearl River mainly comes from the silt carried by upstream river runoff. The river runoff and the sediment, as the dominant factors, is the basic dynamic and substance for the formation of the modern Pearl River Delta.The West River is the main sediment contributor to the Pearl estuary. 2) As compared with the data in the 1960s, the allocation rate of the sediment discharge for the branching channels of the main West River and North River keeps nearly no change. Modaomen is still the biggest sediment delivery river mouth among the 8 estuaries. 3)The sediment in the estuary of the Pearl River tends to be accumulated year by year. No evident variations have been found for the erosion and deposition in the upstream river stretch. Both erosion and deposition occur in the transitional reaches between the upstream river and the estuary, while deposition occurs all over the estuary. 4) The sea level rise and the activities of human being in the Pearl River Delta may cause unfavorable variations of the transport of sediment and runoff and should be taken seriously.