Studies On The Eutrophication And The Spring Phytoplankton Bloom In Xiangxi Bay Of Three-Gorge Reservoir

In view of the eutrophication problem and spring phytoplankton bloom in Xaingxi Bay after the impoundment of Three - Gorge Reservoir (TGR), systematic studies were carried out to research the eutrophication and spring bloom problems in Xaingxi Bay using the methods of landscape ecology and watershed ecology associated with 3S technics and mathematic methods. The main aim of this study is to locate the source of nutrients to Xiangxi Bay, the spatial pattern of nutrients in Xiangxi Bay, and the function of nutrients on the eutrophication process and spring bloom in Xiangxi Bay. The main results are as follows:1. A comparison was carried out to study the changes of the main physical and chemical parameters before (July, 2002– June, 2003) and after (July, 2003– June, 2004) water impoundment of TGR. The results indicated that pH, PO4P, TP, NH3N and NO2N displayed significant difference before and after the impoundment of TGR. After impoundment, the spatial patterns of PO4P and TP changed dramatically and they were enriched in the upstream of Xiangxi Bay because of the dramatic reduction of current velocity. It has a tendency to decrease with the decrease of distance from the river mouth. At the same time, it was found that the eutrophication problems of...