Spatial and temporal variations of sediment flux entering into the South China Sea from 2001 to 2020
Under the influence of human activities and rapid climate change,the fluvial sediments flux entering in-to the South China Sea(SCS)has changed greatly.Based on the hydrological data of rivers around the SCS and sea surface Suspended Sediment Concentration data from 2001 to 2020,this study investigated spatial and temporal variation of sediment flux entering into the SCS.The results show that the sediment flux entering into the SCS ex-ceeds 345 Mt/a during 2001-2020.Human activities result in a reduction of 300 Mt/a in sediment flux from the Zhujiang River,Red River and Mekong River.The sediment flux is also affected by typhoons and climate change:typhoons are the most important factor affecting the sediment flux of small rivers,and the sediment flux of the Gaoping River during the typhoon can reach 89%of total.Under the influence of the East Asian monsoon system,the sediment flux entering into the SCS characterized by significant seasonal variations,the sediment flux is high in wet season and low in dry season.During the wet season,the sediment flux entering into the SCS accounted for more than 80%of total,accordingly,the river plume has the typical characteristics of high concentration and large diffusion range in the wet season.Under the influence of El Niño-Southern Oscillation,the discharge and sediment flux into the sea around the South China Sea also have different periodic changes.The river discharge and sediment flux of large rivers around the South China Sea show a 2.5-3.0 a period,and are correlated with the NIÑO3.4 index,while the sediment flux Taiwan rivers has no obvious period on the interannual scale.Based on data of the 20 a,this study systematically demonstrates the influences of extreme weather,climate change and dam construction on the sediment flux entering into SCS since the 21st century,which is of great significance in the study of source-to-sink processes and watershed management.
South China Seafluvial sediment flux into the seadam constructionclimate change
NETL
NSTL
万方数据
