Features and Degradation of Eco-Environment of Lakes and Marshes along the East Route of the South-to-North Water Transfer Project
南水北调东线工程沿线湖沼湿地生态环境特征及退化分析

The East Route of the South-to-North Water Transfer Project is a strategic area of optimal allocation of water resources in China. Along the East Route, lakes and marshes has developed extensively. They are distinctive ecosystems that have various important services and functions. Most of them belong to inland wetlands with freshwater and shallow water resources, which have abundant biological resources. The biology population structures have obvious comparability. Natural lakes markedly evolved to partially or completely artificial reservoirs. Marshes belong to eutrophication type. The aim of this article is to provide a foundation to study the effects of the East Route of the South-to-North Water Transfer Project on eco-environment of lakes and marshes in the future, and how to protect eco-environment effectively. At the present time, under the interactive impacts of natural and man-made processes, the eco-environment of lakes and marshes degrades obviously, The main characteristics are as follows: water quantity is decreasing, areas of lakes and marshes are diminishing. The pollution of water quality tends to be more serious from south to north, and it also has difference between flood season and non-flood season. Most lakes are in medium or high eutrophication condition. Biological resources of lakes and marshes such as species diversity of fishes diminish gradually, and storage function to flood also descends. Based on these analyses, the article points out the main reasons of degradation, which includes: quick wave of climate in the north part of our country, immobile channel of the Yellow River, drying-up of the Great Canal, blindly reclaim land from lakes and marshes, numerous flood control project and serious point sources and non-point sources pollution. Among which, man-made processes created cumulative impacts on the eco-environment of the lakes and marshes. Besides, over fishing, artificial breeding of fishes and petroleum exploitation also destroyed the eco-environment. At last, mechanisms of degradation are summarized as: natural process is the precondition and basis, and man-made processes are the main driving forces.