River Health Assessment and Control Countermeasures for the Lower Yellow River in Henan
River and lake health assessment is an important technical means to evaluate the health status of rivers and lakes, scientifically analyze river and lake problems, and strengthen the implementation of the river and lake head system. Based on the Guidelines for River and Lake Health Assessment (Trial) and the characteristics and actual basin conditions of the lower Yellow River in Henan, this study determined the river health evaluation index system for this reach. Through collection of basic data and special investigations and monitoring, the health status in 2020 was evaluated from four criteria layers: 'basin', 'water', biology, and social service function. The overall score was 83.4, corresponding to a 'healthy' grade. The four criteria layer scores were 73.7, 95.0, 62.1, and 95.5, respectively. The evaluation identified main problems including low aquatic biodiversity, suboptimal shoreline conditions, and pressure on water supply security. Corresponding governance and protection measures were proposed, such as strengthening ecological protection, improving river regulation works, enhancing shoreline management, and upgrading water diversion facilities. The results provide scientific basis for river health management and the implementation of the river chief system in the lower Yellow River.