Dai, Z.-J.; Chu, A.; Li, W.-H.; Li, J.-F., and Wu, H.L., 2013. Has suspended sediment concentration near the mouth bar of the Yangtze (Changjiang) Estuary been declining in recent years?

There are considerable concerns about the decrease in suspended sediment discharge (SSD) into the large estuaries of the world as a result of extensive anthropogenic activities in their catchment areas. With the operation of Three Gorges Dam (TGD) in 2003, the riverine loads into the Yangtze (Changjiang) Estuary have been greatly changed with the sharp decrease of SSD and suspended sediment concentration (SSC). However, according to our analysis on the SSC in the surfacial water measured at different stations in the Yangtze Estuary, we conclude that the spatial characteristics of the annual mean SSC around the mouth bar area show no apparent change yet, even though the TGD was constructed with an ascending trend at the upper part of the estuary. The spring–neap periodicity of the daily mean SSC after the TGD was constructed remained the same as before. Moreover, the seasonal and annual mean SSC at the inner side of the mouth bar was relatively low due to the large reduction of upstream sediment supply after the operation of TGD began in 2003. But the seasonal and yearly mean SSC at the outer side of the mouth bar during 2007–2009 is comparable with those before the TGD operated, even though there is a decreasing trend of SSC into the Yangtze Estuary in corresponding years.