Investigating the effectiveness of the SWMM model in simulating and evaluating the capacity of Kalat Naderi urban channels for the passage of flood flows

Document Type : Research Article

Authors

• Zinat Hesami ¹
• Mohammad Taghi Dastorani ²
• fateme rezayi ³

¹ Faculty of Natural Resources and Environment, Ferdowsi University of Mashhad.

² Faculty of Natural Resources and Environment, Ferdowsi University of Mashhad

³ Khorasan Razavi Regional Water Company

10.22067/geoeh.2023.82144.1357

Abstract

In this research, which was conducted in a part of Kalat city, first the physical characteristics were estimated and after determining the average water velocity, the concentration time of the studied area was determined based on the length of the main waterway. Then, by using parameters such as intensity-duration-frequency and temporal and spatial distribution of rainfall, the SWMM model was simulated, sensitivity analyzed and evaluated for different return periods. By carrying out sensitivity analysis, it was found that among the 8 parameters used, the percentage of impervious areas has the greatest effect on the peak flow rate. For calibration and evaluation of the model, 5 measured rainfall-run off events were used. Three events were used to calibrate the model, and Nash, RMSE, BIAS% and KGE parameters were used to analyze the results. The results of the model in calibration showed that thre is a good match between the simulated runoff and the observation for the three selected events, as the NS value for the events is greater than 0.5. Remaining two events were also used to evaluate the model, and to analyze the results, the criterion factors mentioned in the calibration stage were used. The evaluation results of SWMM model confirm the efficiency and accuracy of the model results with NS value higher than 0.5. Also, the RMSE values for the simulation events resulting from SWMM model recalibration were 0.01, 0.003, and 0.01 m3/s, respectively. For the simulation events resulting from the model evaluation, the RMSE values were 0.04 and 0.04 m3/s, which indicate the acceptable results of the model. As a result, it can be said that there is a good agreement between the simulated and observed runoff, and this shows that the SWMM model has the required accuracy for urban runoff simulation.

Keywords

• urban runoff
• SWMM model
• urban channels
• flood

Main Subjects

• Urban environments hazard and their management

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