River health evaluation and impact factor analysis of Yuanjiang River Basin

In order to comprehensively evaluate the river health status of YuanJiang River Basin and find the distribution characteristics, three river health evaluation index systems were established respectively for the main stream of YuanJiang River and its main primary tributaries, which named Wushui and Youshui River. The health status of above three rivers has been analyzed, and the main factors affecting the health of rivers were identified by principal component analysis. The results had shown that the scores of various evaluation sections of three rivers were generally higher or approaching than 80 points, the overall health condition was good and the differences between upstream and downstream were small. The longitudinal connectivity index of the river, sediment pollution status, fish retention index, aquatic plant community status, integrity index of large benthic invertebrates and flood control compliance rate had a significant impact on the river health status of Yuanjiang River Basin. The research results were consistent with the investigation, which can provide a theoretical support of management and protection of rivers, water resource development and utilization, water ecological restoration for Yuanjiang River Basin and the entire Hunan Province.