Water Resources and Power

The problem of standard disconnection often exists in the two-level drainage mode of plain river network cities in China. As a result, when heavy rainfall occurs, the hydraulic characteristics and drainage capacity of pipe network system are affected by both rainfall intensity and water level of drainage water, making it difficult for waterlogging to discharge out. Therefore, taking the municipal drainage system and water drainage system of Suzhou Industrial Park as an example, the multi-scenario flood process simulation based on SWMM was carried out, and the analysis showed that when the river water level was between 1.70 m and 2.30 m, the main reason for the water accumulation in the study area was the insufficient capacity of the current pipe network system itself, and the river water level aggravated the water accumulation. When the water level exceeded 2.30 m and keep rising, the drainage capacity of the pipe network system decreased sharply, and the river level gradually became the main factor restricting the flow capacity of the pipeline and aggravating the degree of water accumulation. It is suggested that the maximum water level for river drainage control in the study area should be around 2.30-2.32 m. This conclusion can provide reference for urban river level regulation to improve urban drainage and waterlogging capacity.