Based on the monitoring data of Poyang Lake in four hydrological periods, wet, rising, dry and retreating in 2014 and 2018, the extension evaluation method was introduced to evaluate the health of Poyang Lake aquatic ecosystem and analyze the influence of index dynamic weight. The results showed that the health status of Poyang Lake aquatic ecosystem varied significantly in different hydrological periods, with the best in retreating period, the worst in dry period, and a slightly better in rising period than in wet period. The index weight of Poyang Lake aquatic ecosystem health assessment had dynamic characteristics. The index weight value varied with the specific value of the index. Even if the index value was the same, the relationship between indicators were different, and the index weight was different, which affected the evaluation result of Poyang Lake aquatic ecosystem health. The ecosystem function and structure of Poyang Lake differed greatly in different periods. It was more reasonable to use dynamic weight to evaluate the aquatic ecosystem health. |