Evolution of the Hydrological and Hydrodynamic Characteristics in the Outlet Reach of Xiangjiang River

Abstract

In this study, a one-dimensional hydrodynamic model in the lower reaches of Xiangjiang River is constructed to conduct a simulation of the hydrodynamic characteristics of the lower reaches in Xiangjiang River. In this model, the backwater effect of Dongting Lake is taken into account to define the range of the outlet reach of Xiangjiang River. Observed hydrological data in a rather long period, i.e. 1980-2008, in Xiangjiang River and Dongting Lake basin are systematically collected, to further analyze the evolution pattern of hydrological and hydrodynamic characteristics in the outlet reach of Xiangjiang River. The results show that the range of the outlet reach of Xiangjiang River is 100km away further up from the lake inlet, which is within the region of Xiangtan, which is within Xiangtan region. The backwater effect can be found annually in the period from June to October. The findings from this study may have implications on studies of the evolution of river-lake relation and the eco-environmental effect, and provide scientific basis for water resources development and eco- environmental protection in the outlet reach of Xiangjiang River.