A novel method to quantify misconnected nodes’ reconstruction effects and sewage routing path of drainage system during rainy season

In order to simulate the effects of reconstructing misconnected nodes in the drainage system and quantify sewage routing paths during the rainy season, we have selected a specific region in Fangchenggang City as our study area. All misconnected nodes have been divided into 10 areas based on their respective blocks and streets. COD, NH4+-N, TN, and TP are chosen as evaluation indexes, and we have utilized SWMM for modelling purposes. The results indicate that nodes located upstream within the drainage watershed tend to have a broader influence scope, with a maximum pollutant load reduction rate of 8.6%. However, it is worth noting that the normalization effect could worsen if a reconstruction scheme contains more nodes. Our methodology for calculating the pollutant load reduction rate of pipelines presents a novel approach for quantifying pollutant reduction effects, sewage flow paths, and geographical visualization. This approach has the potential to address the knowledge gap in exploring pollutant transfer routes