Abstract:

The deposition rate of different zones of Lake Taihu was evaluated at two stages (1963~1983,1983~2002).The results showed that the deposition rates increased at different degrees in space,and the East Lake was the most significant in Lake Taihu.It increased from 29 mm/a to 124 mm/a. Since deposition rate has different meaning to different depth of shallow lake,the relative deposition rate (RDR) was proposed to assess the health states of Lake Taihu in deposition.RDR is the ratio of deposition rate to depth.The health index was determined by the deposition situation of the principal domestic lakes.The lake of maximum  RDR was defined as health score of 0,and the lake of RDR being 0 was defined as health score of 100,thus the health index of Lake Taihu could be calculated by linear interpolate.The RDR shows that Gonghu bay and Centre lake are in health states,East lake is the only unhealth zone,and the others are subhealth.The whole lake has a deteriorate trend from subhealth to unhealth.