Urban inundation due to any kind of inefficiency or defect of urban drainage systems causes considerable damage in buildings and other private and public infrastructure and is among destructive and the common natural hazards (Chen et al., 2018b Hammond et al., 2015 Price & Vojinovic, 2008 Tingsanchali, 2012). Complexities in the drainage infrastructures and urban areas have a natural influence on surface runoff that this runoff causes urban inundating (Chen et al., 2009 Jamali et al., 2018). This results in increased water pollution, hydrocarbons, heavy metals, pathogens and nutrients (Phillips et al., 2018 Pitt and Jr, 2001 Qin et al., 2016). Urbanized areas are accompanied by increase in impervious areas such as construction of drainage systems, roads, roofs, destruction of soils structure, and destruction of vegetation due to growth urban area (Hsu et al., 2000 Hung et al., 2018 Kamali et al., 2017 Shuster et al., 2005 SillanpГ¤Г¤ & Koivusalo, 2015). In addition, the result of inundation hazard map indicates that 8.2% of the case study is determined as a high hazard zone. Simulated results can be used to develop urban inundation hazard forecasts. The results showed that the combined model (SWMM and HEC-RAS) was suitable to analyze urban inundation and determine inundation hazard zones on urban areas. Then, six factors such as distance from the main channel, slope, land use, drainage density, the main channel slope and elevation were selected to determine inundation hazard map using Analytic Hierarchy Process (AHP). The simulated runoff in the SWMM model is used as input to the HEC-RAS model and determines inundation hazard zones in 5, 25 and 50 return periods. In this study, the Storm Water Management Model (SWMM) is used to simulate the rainfall-runoff in the study area. Therefore, to manage urban areas and prioritize regions to inundation elimination problems, the area most affected by inundation should be determined. Land use changes, increasing urbanization, unauthorized construction, inefficiency of sewage system and increased impervious surface in urban areas have significant impacts on inundation hazard. In recent years, rapid urbanization has led to change of rural areas into urban areas, and urban runoff will increase as the result of spread and growth of impervious areas. Extensive impervious area and the man-made streams are the characteristics of urban areas.

Flooded in pro ii simulation