ZHU Yao 1, LIAO Wen-gen 2, FENG Shun-xin 2 (1. Division of International Cooperation, IWHR, Beijing 100038, China, 2. Research Center for Sustainable Hydropower Development, IWHR, Beijing 100038, China)

Abstract: Tian-e-zhou Oxbow of Yangzi River is a half-manual habitat of Yangtze finless porpoise. It is the first successful case of off-site preservation of cetacean in the world. Studying the features of Tian-e-zhou oxbow would take a large benefit for selecting other off-site preservation area for Yangtze fin less porpoise. This paper built a 2 dimensional model of Swan Oxbow based on DHI MIKE21 software to study the wind-driven circulation in the oxbow. The thesis discussed the flow field, speed, water depth, flux of different zone for different seasons in this oxbow. The thesis also discusses the relationship between the water quality, food, topographic conditions and the requirement of habitat of finless porpoise. The thesis is intended to integrate the ecological behavior of finless porpoise with hydraulic situation and find the basic requirement of habitat of finless porpoise. Analyses show that the finless porpoise prefers some reaches which have riffle-pool, composite cross section and complex fluid state. The wind-driven circulation has a certain influence on the choice of habitat for finless porpoise. Analysis also shows that the water level of Oxbow could only meet the required water level of core zone. The water level of buffer zone and pilot zone cannot be guaranteed.

Key words: Yangtze finless porpoise, Tian-e-zhou Oxbow of Yangtze River, habitat, topography, hydrological characteristic, hydrodynamic characteristic

Published in: Journal of China Institute of Water Resources and Hydropower Research (Vol. 10 No. 3, 2012)