Assessing lake health in China: Challenges due to multiple coexisting standards

Abstract

Study Region: Yangcheng Lake is located northeast of Suzhou city, one of the most economically developed cities in the Yangtze River Delta plain, China. Yangcheng Lake serves as a storage pool for flood control and water diversion; as well as a potable water source for Suzhou City. In recent years, summer cyanobacterial blooms began appearing in Yangcheng Lake, which urgently requires a health evaluation. Study Focus: Currently, there is a three-tier analysis system consisting of national, provincial, and local assessments in China. However, each tier has a unique set of standards, meaning that: 1) evaluations between tiers are not comparable and 2) conducting a unified survey and analyzing the results is exceedingly difficult. How to develop ways to standardize existing river and lake health evaluation systems in China become a global concern. New Hydrological Insights for the Region: Although the evaluation index system and assessment techniques are consistent throughout all three methods, they differ in their handling of index weights and assignment criteria. The health evaluation scores of Yangcheng Lake are in the Healthy to Sub-healthy range, with gradually decreasing health from east to west. This work synthesized the existing Chinese national-provincial-local health evaluation system and suggested standardizing the index system, index weights, and evaluation process to provide theoretical support for water resources management and water ecology restoration in freshwater water bodies in China.

Keywords

• Health assessment normalization
• Aquatic ecological health
• Ecological integrity
• Yangcheng Lake