Seite - 1008 - in Book of Full Papers - Symposium Hydro Engineering

COMMISSION INTERNATIONALE DES GRANDS BARRAGES ------- VINGT-SIXIÈME CONGRÈS DES GRANDS BARRAGES Autriche, juillet 2018 ------- MAIN ECOLOGICAL RISKS FACING THE YANGTZE RIVER BASIN, EXISTING PROTECTIVE MEASURES AND THEIR EFFECTIVENESS ZHU DI & YANG ZHI Key Laboratory of Hydroecological Effects and Ecological Restoration, MWR, INSTITUTE OF HYDROECOLOGY, MWR & CAS CHINA 1. INTRODUCTION The Yangtze River flows for 6,300 kilometers. It is the third longest river in the world. The Yangtze River Basin is a world hot spot of biodiversity, inhabited by over 400 fish species, of which some 350 are freshwater fish and up to 156 are endemic fish (Cao, 2011). Human activities such as water engineering and reclamation have led to changes in the aquatic inhabit, which then affect the reproduction and multiplication of aquatic organisms; the destruction of aquatic communities in turn affects the environment that humans depend on for survival. At present, the major hydroecological risks facing the Yangtze River Basin include decline in aquatic biodiversity, partial loss of biological habitats, water pollution, and reduction in river connectivity. 2. DECLINING AQUATIC BIODIVERSITY 2.1. REDUCTION IN SPECIES NUMBER The Yangtze River is a wide diversity of unique species, when flooding occurs, provides us with abundant aquatic organisms. Flooding may be a disaster 1008