Classification of highly turbid Jiaojiang Estuary

The Jiaojiang Estuary is shallow,macro-tidal dominated and extremely turbid,with a larger variation of the freshwater discharge.The estuarine stratification and classification are analysed by using a set of field data observed in wet season.
In spring tide,the depth-mean peak tidal currents can reach 2 m/s.During flood tide the water column is vertitally homogeneous,but the horizontal salinity gradient is large and there is a fresh water front.A 1 m thick fluid mud layer capped by lutocline is formed when the tidal current is less than 0.3 m/s.As the low-salinity trapped in the fluid mud layer,underlying saltier water enhances vertical mixing when the fluid mud layer is eroded and the water column is only slightly stratified during ebb tide.