The bedform morphology of Chinese sturgeon spawning sites in the Yangtze River  

作　　者：Yu-jun YI Shang-hong ZHANG Zhao-yin WANG 

机构地区：[1]Ministry of Education Key Laboratory of water and sediment Scienc,Beijing Normal University [2]State Key Joint Laboratory of Environment Simulation and Pollution Contro Beijing Normal University [3]Renewable Energy School,North China Electric Power University [4]State Key Laboratory of Hydroscience and Engineering,Department of Hydraulic Engineering,Tsinghua University

出　　处：《International Journal of Sediment Research》2013年第3期421-429,共9页国际泥沙研究（英文版）

基　　金：financially supported by the National Natural Science Foundation of China(No.50939001 and No.51279220);the Nonprofit Environment Protection Specific Project of China(No.201209029-4)

摘　　要：Quantitative measures of the relationships between channel morphology and the habitat use of Chinese sturgeon （Acipenser sinensis） can help management and regulatory agencies to quantify potential spawning habitats and develop recovery goals in view of the decreasing area of sturgeon spawning habitat.This study determined the specific bedform types at the pool-riffle scale and evaluated the slopes,aspects and bed load gradation composition of Chinese sturgeon spawning areas in the Yangtze River,China.A bedform differencing technique was used to objectively quantify the longitudinal riverbed profile into four distinct pool-riffle units that were independent of discharge.The vertical location of thalweg points within these units was quantified with a riffle proximity index.Chinese sturgeon spawning areas were mapped and correlated with the pool-riffle units,slopes and aspects.The results indicate that Chinese sturgeon spawning areas occur primarily in rifties.The majority of Chinese sturgeon spawning occurred at elevations greater than 75％ of the difference in elevation between the nearest riffle crest and the pool bottom.The slope of spawning sites was distributed between 0.05 and 6.36,and the average aspects were 219.92 and 207.63,respectively.The bed load is mainly composted of gravel and pebble,sediment diameter concentrated on 50-500mm.These analyses of bedform morphology will assist regional fish managers in quantifying existing and potential Chinese sturgeon spawning habitats and will provide a quantitative framework for evaluating general ecological implications of channel morphology in the Yangtze River.Quantitative measures of the relationships between channel morphology and the habitat use of Chinese sturgeon （Acipenser sinensis） can help management and regulatory agencies to quantify potential spawning habitats and develop recovery goals in view of the decreasing area of sturgeon spawning habitat.This study determined the specific bedform types at the pool-riffle scale and evaluated the slopes,aspects and bed load gradation composition of Chinese sturgeon spawning areas in the Yangtze River,China.A bedform differencing technique was used to objectively quantify the longitudinal riverbed profile into four distinct pool-riffle units that were independent of discharge.The vertical location of thalweg points within these units was quantified with a riffle proximity index.Chinese sturgeon spawning areas were mapped and correlated with the pool-riffle units,slopes and aspects.The results indicate that Chinese sturgeon spawning areas occur primarily in rifties.The majority of Chinese sturgeon spawning occurred at elevations greater than 75％ of the difference in elevation between the nearest riffle crest and the pool bottom.The slope of spawning sites was distributed between 0.05 and 6.36,and the average aspects were 219.92 and 207.63,respectively.The bed load is mainly composted of gravel and pebble,sediment diameter concentrated on 50-500mm.These analyses of bedform morphology will assist regional fish managers in quantifying existing and potential Chinese sturgeon spawning habitats and will provide a quantitative framework for evaluating general ecological implications of channel morphology in the Yangtze River.

关 键 词：Riverbed morphology Pool-riffle units Slope Aspect Chinese sturgeon 

分 类 号：S931[农业科学—渔业资源]