Extensive impervious area and the man-made streams are the characteristics of urban areas. 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. Land use changes, increasing urbanization, unauthorized construction, inefficiency of sewage system and increased impervious surface in urban areas have significant impacts on inundation hazard. Therefore, to manage urban areas and prioritize regions to inundation elimination problems, the area most affected by inundation should be determined. In this study, the Storm Water Management Model (SWMM) is used to simulate the rainfall-runoff in the study area. 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. 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 results showed that the combined model (SWMM and HEC-RAS) was suitable to analyze urban inundation and determine inundation hazard zones on urban areas. Simulated results can be used to develop urban inundation hazard forecasts. In addition, the result of inundation hazard map indicates that 8.2% of the case study is determined as a high hazard zone.

中文翻译：

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伊朗城市地区洪水淹没危害调查与模拟

大面积的不透水面积和人造溪流是城市地区的特点。近年来，快速城市化导致农村地区向城市地区转变，城市径流将随着不透水区的蔓延和增长而增加。土地利用的变化、城市化进程的加快、未经授权的建设、污水系统效率低下以及城市地区不透水面的增加对洪水灾害产生了重大影响。因此，为了管理城市地区和优先解决淹没消除问题的区域，应确定受淹没影响最大的区域。在本研究中，雨水管理模型（SWMM）用于模拟研究区的降雨径流。SWMM 模型中的模拟径流用作 HEC-RAS 模型的输入并确定 5 中的淹没危险区，25 和 50 返回期。然后，选取距主河道距离、坡度、土地利用、排水密度、主河道坡度和高程等6个因素，采用层次分析法（AHP）确定洪水灾害图。结果表明，组合模型（SWMM 和 HEC-RAS）适用于分析城市淹没和确定城市地区的淹没危险区。模拟结果可用于制定城市洪水灾害预测。此外，淹没危险图的结果表明，8.2%的案例研究被确定为高危险区。结果表明，组合模型（SWMM 和 HEC-RAS）适用于分析城市淹没和确定城市地区的淹没危险区。模拟结果可用于制定城市洪水灾害预测。此外，淹没危险图的结果表明，8.2%的案例研究被确定为高危险区。结果表明，组合模型（SWMM 和 HEC-RAS）适用于分析城市淹没和确定城市地区的淹没危险区。模拟结果可用于制定城市洪水灾害预测。此外，淹没危险图的结果表明，8.2%的案例研究被确定为高危险区。