Assessment Uncertainty of SWMM Urban Flood Model Using GLUE MethodCase Study: 2nd District Municipality of Tabriz

Given the complexity of urban environments, flood risk has increased in urban areas in recent years. In order to estab-lish a correct urban management, the control and optimal use of surface water should be carefully understood from the complex rainfall-runoff process in urban environments. The problems of urban basins are the lack of precise input pa-rameters, the lack of knowledge of the runoff production process, the lack of a flow measurement system at the outlet of sub-basins to calibrate and uncertain input parameters, and the results of mathematical and numerical models such as SWMM. This research investigates and analyzes the uncertainty of the GLUE method at levels in District 2 of the Metropolitan Municipality of Tabriz, with SWMM urban flood model. In order to quantify the uncertainty, the initial range of input parameters including CN, impervious, N pervious and N-impervious was determined. Using the GLUE algorithm, initial sampling operations were performed using parametric space by lattice square sampling. According to the results of simulations and the magnitudes of observational events, 20% of the total outputs and the series of gener-ated parameters were separated as acceptable simulations. According to the results of the evaluation of the distribution diagrams, Imperv% and N Imperv input parameters were identified as sensitive and effective parameters on model simulation and the range of parameters was obtained.