Impacts of Hydraulic Engineering on Wetland Flood Inundation and Management Implications

Wetlands provide numerous ecosystem services and are important habitats for rare species. Flood inundation promotes material and energy cycling in wetlands, which is crucial for maintaining wetland ecosystem health. Hydraulic engineering construction and regulation disrupt the natural hydraulic connection between rivers and wetlands, reshaping flood propagation pathways and inundation patterns. In this study, coupled hydrological and hydraulic models were used to simulate flood inundation processes under natural and regulated conditions for wet, normal, and dry years. The results indicated that hydraulic engineering regulation reduced the total inundation area in wet years by 7.12% while slightly increasing the perennial inundation area in normal and dry years by 2.80% and 2.20%, respectively. Hydraulic engineering leads to the development of persistent flow paths that remain inundated during dry periods, whereas peripheral areas experience diminished flood frequency, weakening lateral hydrological connectivity, thus limiting the ecological benefits of floods. The drought-prone areas resulting from hydraulic engineering construction and regulation are key targets for wetland management. These findings enhance the understanding of hydraulic engineering in reshaping wetland hydrological processes and provide guidance for wetland management and conservation.