Where do waterbirds settle down under heavy rain: Waterbird habitat planning and design from the perspective of rain and flood resilience

Abstract

Urban wetlands have ecological functions such as maintaining biodiversity and regulating runoff, and wetland waterbirds are also important biological indicators of wetland ecosystems, which can reflect the ecological conditions of wetlands and cities. In recent years, extreme weather occurs frequently, urban waterlogging is serious, rivers play the role of flood drainage, and rainwater backflow will have a serious impact on urban rivers, wetlands and aquatic organisms. Therefore, it is necessary to explore the inundation of urban wetlands under extreme rainfall conditions. In the past, most of the research on waterlogging was from the perspective of disaster prevention, and there was little research on the degree of habitat destruction of waterbirds. In this paper, the HEC-RAS hydrological model was used to simulate the extreme rainfall of the Shiwuli River in the study area of Hefei City, and the results showed that once a rainstorm occurred, the downstream wetland would be flooded in a large area and the inundation height would exceed the flood defense level, which would have a serious impact on the swimming birds such as coots nesting in the downstream wetland. Therefore, the landscape, foraging and habitat conditions of Coots were selected as the design factors, and the floating bird island was designed to alleviate the invasion of rain and flood waterlogging on Coots. The innovation of this study is to propose an optimization strategy for the impact of extreme weather on waterfowl habitat, which can provide a reference for waterfowl protection and wetland management, and improve the impact of environmental changes such as waterlogging caused by extreme rainfall on downstream lakes on waterfowl populations.