River health assessment: Proposing a comprehensive model based on physical habitat, chemical condition and biotic structure

Rivers provide many eco-services functions for human being, but with the intensive impacted by human activities, river health had been leading to the poor condition. In this study, an assessment index system including eleven elements consisting of physical habitat, chemical condition and biotic structure were established to assess river health in the Wei River Basin. The improved gray incidence model and comprehensive rough set weight model were combined as the assessment. The results indicate that the river health of Wei River, Jing River and Beiluo River were at the sick level, and the whole Wei River Basin was at the sick level too, land use changed, water pollution are the most important influence factors affected the river health. Compared with other models, the uncertainties can be mostly eliminated and the assessment index's weight can be determined more objective, the proposed method is effective and feasible for river health assessment. The research results are aimed to provide a scientific basis for improving river health and water allocation to the policy makers.