Effects of the human activities on the water level process of the Poyang Lake

Abstract

The hydrological cycles in basin is profoundly affected by human activities. Yangtze River is a world class river with complex river-lake relations in the middle reaches. As the Three Gorges Reservoir (TGR) and other controlled reservoirs in the main stream and tributaries have been put into operation, the water regimes of the main stream in the middle reaches and Poyang Lake have been changed by water impounding and sediments trapping, clean water discharged from reservoirs, accelerating the evolution of the relationship of river and lake. After entering the 21st century, autumn droughts become more serious in Poyang Lake basin; the relationship between river and lake becomes tense. In light of the hydrological data in Poyang Lake since 2000s, this article made quantitative analyses of the influences of the human activities on the variation of the Poyang Lake level by authors. The results indicate that the main stream of Yangtze River, particularly the regulation of Three Gorges Reservoir, exerts a profound influence on the variation process of the Poyang Lake level. The regulation influence of the Upper Reach of the Yangtze River’s Reservoir Group (URYRRG) could spread to Tangyin area in the middle of the lake in October.