Urban HydroConnect: Harnessing SWMM for Dynamic Waterway Management Assessment

This study conducted a comprehensive analysis of flood control and water quality simulation for the urban water system in Runan County, with the aim of evaluating the conditions of urban waterlogging and changes in water quality before and after the management of the urban water system. This provides significant scientific basis and technical support for the water system management and water environment protection in Runan County and similar urban areas. The study employed a rapid modeling technique assisted by ArcGIS and the SWMM (Storm Water Management Model) for the first time to conduct an in-depth simulation study on the regulation of floods and the improvement of water quality in the central urban area of Runan County. By simulating design rainfall scenarios of 1-h and 6-h durations for return periods of 3, 5, 10, 20, and 50 years, a detailed analysis was performed on the extent of flood inundation in the urban area of Runan County under different rainfall conditions and the flood detention capacity of the river channels. Furthermore, for rainfall scenarios of 3, 10, and 50-year return periods, a meticulous simulation analysis was conducted on the water quality response and the attenuation process of pollutant concentrations in the main river channels. The results of the study revealed the significant effects of river channel regulation on enhancing the connectivity of the water system and the capacity for flood control: the regulation of river channels significantly increased the cross-sectional area and the volume of water in the channels, leading to a reduction in pollutant concentrations along the direction of the river flow. Comparing the data before and after the management, the extent of the flood-prone area and the volume of water entering the river in the non-managed water system were 1.4 times and 59% of those after management, respectively, indicating that the comprehensive management of the water system significantly reduced the risk of waterlogging. In addition, the self-purification capacity of the river channels and the efficiency of pollutant degradation improved significantly after the management, effectively enhancing the water quality environment.