COMPREHENSIVE ASSESSMENT OF THE WATER ECOLOGICAL SECURITY OF THE XIANGJIANG RIVER BASIN BASED ON PHYSICO-CHEMISTRY AND ORGANISM INDICES

The water ecological security of a river basin affects the vigorous growth of the regional economy and the healthy development of the ecological environment. Based on river physics, chemistry, and biological indicators, this study constructed a comprehensive assessment index system for the water ecological security of the Xiangjiang River Basin in China. The system consisted of 6 elements, and 18 indicators. This study used the analytic hierarchical process (AHP) to evaluate the water ecological security of the upstream, midstream, and downstream environments of the Xiangjiang River Basin. The results show that the overall ecological security of the upper and midstream portions of the Xiangjiang River Basin is relatively good, while the downstream section is at a general level. The three indicators that are given the most weight in the indicator system are the fish bio-loss index, the degree of ecological flow satisfaction, and the compliance rate of the water function zone. The less significant indicators are the natural wetland retention rate, riparian vegetation coverage, riparian human activity, and riverside connectivity. The research results of this study can provide a reference for the ecological restoration of regional rivers and the protection of Xiangjiang River.