长江流域鱼类多样性与流域特性关系分析

Analysis on the relationship between fish diversity and watershed features in the Yangtze River Basin

鱼类多样性是反映流域水生态系统的关键指标。该文基于鱼类多样性分析了影响长江流域水生态系统的主要因素。采用相关分析和灰色关联分析识别了影响鱼类多样性的主要因素。进一步通过多元线性回归建立了鱼类多样性与流域特性之间的定量关系。结果表明：影响长江上游干支流鱼类多样性的主要因素是海拔和流域面积等自然因素,除了通天河、金沙江上段、雅砻江等海拔3 500m以上的流域之外,其他上游干支流的主要影响因素是径流量。中下游鱼类多样性的主要影响因素从自然因素转变为土地利用类型,反映出人类活动对水生态系统的影响逐渐增强。

Fish diversity is a key indicator of the quality of a river water ecosystem.This study used the fish diversity to analyze the main factors influencing the Yangtze River water ecosystem.A correlation analysis and a gray correlation analysis were used to identify the main factors influencing the fish diversity. A quantitative relationship between the fish diversity and the watershed features was developed using a multiple variable regression.The results show that the main factors influencing the fish diversity in the mainstream and its tributaries in the upper reaches of the Yangtze River are natural factors such as elevation and basin area.Runoff is the main factor influencing the mainstream and its tributaries in the upper reaches except Tongtian,the upper part of Jinsha River and the Yalong River with altitude exceeding 3 500 m.The main factor influencing the fish diversity in the middle and lower reaches is land use types.The transition of the key factors from natural factors to land use types reflects the increasing influence of human activities on the river water ecosystem.