Evaluation of the network performance of surface water collection and guidance using the SWMM Hydrological Model (Case Study: District 6 of Tehran Municipality)

In this study, the EPA-SWMM model was used to simulate the flood-induced rainfall 6 hour showers with a return period of 2, 5 and 10 years and for 12 hours.The results indicate that some of the network parts that contain a number of nodes and ducts leading to critical paths showed that due to the large volume of flow in some areas there is no ability to run runoff in existing conditions , Which is the main cause of flooding, the smallness of the cross section of the ducts, as well as the low slope in some of the gorges. In this study, in order to validate the model, 5 rainfall events were used and runoff speed was calculated. The model's performance indicators in this research include Nash-Sutcliff, error square root and bias. The results of calibration of the model showed that there is a good agreement between simulated and observational data and indicates the high accuracy of the model for this area, so that the amount of NS (NS) for precipitation events is 0.88, 0.71, 0.89, 0.74 and 0.77, and it has been determined that the cause of flooding in some channels and channels is due to lack of sufficient capacity of the channels. Based on the above results, in general, this model can be used in appropriate design and evaluation of the system Municipalities used urban drainage networks.