Simulating Ecological Effects of a Waterway Project in the Middle Reaches of the Yangtze River Based on Hydraulic Indicators on the Spawning Habitats of Four Major Chinese Carp Species

The adaptability of fish to their habitats is closely related river hydraulics. While navigation channel projects aim improve the conditions by adjusting hydrodynamic force local sections, impacts these on hydraulic indicators four major Chinese carp species (FMCCs) remain unclear. Taking Daijiazhou reach in middle reaches Yangtze River as a case study, mathematical model for spawning suitability was established simulate changes before and after implementation project. optimal flow rate interval FMCCs 17,500–22,000 m3·s?1. After project implemented, habitat index (HSI) weighted useable area (WUA) increased across all FMCCs, indicating that created more space. central bar (Chihugang bar) became exposed during dry season, with HSI WUA decreasing under low water but increasing medium-low or higher levels. At head floodplain, which remained unexposed implementation, providing space habitation FMCCs. For point bank gullies (Lejiawan bar), protection zone restricted gully development, Based above environment habitats, this paper provides reference optimization arrangement well restoration habitats.