Based on the significant impact of the operation of the Xiangjiaba Hydropower Station in the upper Yangtze River on the downstream hydrological regime and river geomorphology, this study takes the historical spawning grounds (Anbian, Sankaishi, Xuetan) of the Yangtze sturgeon (Acipenser dabryanus) as the research object. By comparing hydrological data, topographic surveys, and hydraulic parameters before and after dam construction (1965–1975 vs. 2020–2022), we systematically analyze the process and mechanistic effects of habitat parameter changes on the decline of its spawning capacity. The results show that dam operation led to an increase in the variability of monthly average flow (standard deviation increased from 532 to 998), higher flow reversal frequency, and significantly elevated rates of flow rise and fall. The hydrological rhythm shifted from natural and steady to pulsed regulation, disrupting the hydrological stability essential for Yangtze sturgeon spawning. Meanwhile, changes in water depth, flow velocity, substrate conditions, and vorticity in the spawning grounds further reduced their suitability. This study reveals how dam regulation alters hydrology and topography, leading to systematic degradation of the spawning habitat of the Yangtze sturgeon, thereby providing a scientific basis for its conservation and ecological scheduling.
 

Historical spawning grounds、Hydrological data、Bathymetric survey、Hydraulic parameters