A new method for the estimation of fine-sediment resuspension ratios in estuaries—taking the turbidity maximum zone of the Changjiang(Yangtze)estuary as an example

摘要

Based on the principle of conservative matter removal in estuary,a new method is proposed for estimating the ratio of sediment resuspension in estuaries with fine suspended sediments in the turbidity maximum zone(TMZ)of the Changjiang(Yangtze)estuary during 2005.Results show that there was a range of 18.7％±27.9％ to 73.9％±22.5％ per annum of total suspended particulate matter(SPM),with an average of 49.2％.Nearly half of the particulate matter in the TMZ originates from sediment resuspension.This indicates that sediment resuspension is one of the major mechanisms involved in formation of the TMZ.Compared with traditional method for calculating these ratios in the estuary,this new method evaluates the dynamic variation of SPM content carried by river runoff from the river mouth to the ocean.The new method produced more reliable results than the traditional one and could produce a better estimation of resuspension flux for particulate matter in estuaries.