长江口悬沙浓度变化的同步性和差异性(英文)

编号 zgly0001584695

文献类型 期刊论文

文献题名 长江口悬沙浓度变化的同步性和差异性(英文)

作者 杨云平  邓金运  张明进  李义天  刘万利 

作者单位 KeyLaboratoryofEngineeringSediment  TianjinResearchInstituteforWaterTransportEngineering  MinistryofTransport  StateKeyLaboratoryofWaterResourcesandHydropowerEngineeringScience  WuhanUniversity 

母体文献 Journal of Geographical Sciences 

年卷期 2015年04期

年份 2015 

分类号 TV148 

关键词 suspendedsedimentconcentration  synchronicity  difference  sedimentdischarge  YangtzeRiverEstuary 

文摘内容 The sediment discharge from the Yangtze River Basin has a stepwise decreasing trend in recent years. The impounding of the Three Gorges Reservoir exacerbated this decreasing trend and affected the change of the suspended sediment concentration(SSC) in the Yangtze River Estuary through the transmission effect. The SSC data of the Yangtze River Estuary during 1959–2012 showed that:(1) The SSC in the South Branch of the Yangtze River in the estuary and in the off-shore sea area displayed decreasing trends and decreased less towards the sea. At the same time, the difference in decreasing magnitude between SSC and sediment discharge became bigger towards the sea.(2) For the North Branch the preferential flow did not change much but the SSC tended to decrease, which was mainly caused by the decrease of SSC in the South Branch and China East Sea.(3) Due to the decreased runoff and the relatively strengthened tide, the peak area of the SSC in the bar shoal section in 2003–2012 moved inward for about 1/6 longitude unit compared with that in 1984–2002, and the inward-moving distance was in the order of flood season > annual average > dry season.(4) In the inlet of the South Passage, the SSC decreased mainly because the increase caused by resuspension and shore-groove exchange was less than the decrease caused by the sharp SSC decrease in the basin and the sea areas. The reverse was true in the middle section, where the SSC showed an increasing trend.(5) In the inlet of the North Passage, under the combined influence of decreased flow split and sediment split ratios, the decreased SSC in the basin and the sea area and decreased amount of resuspension, the SSC displayed a decreasing trend. In the middle section, because the increased amount caused by sediment going over the dyke was markedly more than the decreased amount caused by external environments, the SSC tended to increase. Holistically, the sharp decrease in sediment discharge caused synchronized SSC decreases in the Yangtze River Estuary. But there were still areas, where the SSC displayed increasing trends, indicating synchronicity and difference in the response of SSC to the sharp decrease in sediment discharge from the basin.