Ecological Response Characteristics of Interconnected River System Network in Karst Area: A Case Study of Dabang River Basin Connecting Engineering in Guizhou Province

Abstract

As an important water control strategy in the 21st century, interconnected river system network has been widely implemented in all parts of China. However, the possible ecological response mechanism which can be decided by the structure of rivers and the river-lake connectivity is still in the exploratory stage at present, especially in karst areas where the ecosystem is particularly fragile. Taking the Huangguoshu Waterfall-Wangerhe reservoir connection engineering in Dabang River Basin of Guizhou Province as an example, this paper collects the basic data of hydrometeorology, vegetation coverage and river water quality in the Dabang River Basin in the past 20 years, and study and analysis the connectivity of water system and the ecological factors based on GIS which include meteorological, terrestrial habitat and water environment before and after the completion of the Link Project. The results show that the implementation of the project not only changes the connectivity pattern of river and lake systems, but also has a significant impact on the hydrometeorology, terrestrial habitat and water environment. The increase of connectivity leads to the decrease of regional rainfall, evaporation and temperature year by year, while the vegetation coverage and water temperature show an annual upward trend. In addition, the water quality of the receiving area is better after the implementation of the river-lake link project, which does not bring water pollution risk to the receiving area.