关键词: 河道整治, 长江江豚, 分流区, 分离区, 汇流区, 流态

Abstract: The Yangtze finless porpoise (Neophocaena asiaeorientalis asiaeorientalis)is an endemic mammal in the middle and lower reaches of the Yangtze River,and generally appears around river bars and shallow edge beaches. The river training produces negative impacts on the cetacean because of alteration of the hydrological environment for fishes. Using three surveys in the Dongliu section of the Yangtze before the river training project and another three surveys after the project group structure and size of the porpoise in three flow patterns were compared. The results showed that the Yangtze finless porpoise were found mostly in separations near side bars,and secondly in bifurcations above a bar before river training.After implementation,the annual rate of decrease of the porpoise was about 8.9% .The Yangtze finless porpoise has vanished in the bifurcation zone,and is less dense in the separation zone while rapidly shifting among flow patterns in the regulated river.The results of this study also suggest that the Yangtze finless porpoise is exposed to more and more difficulty in the mainstream of the river.It is urgently that the Yangtze finless porpoise be translocated into an old channel from the mainstream of the Dongliu section.

Key words: Bifurcation zone, Confluence zone, Flow pattern, River training, Separation zone, Yangtze finless porpoise