Vulnerability and Reliability of the Runoff Collection Network of District 10 of Tehran Municipality in the Face of Urban Flooding

Population increase, urbanization and consequently increase of impervious surfaces has caused an increase in the volume of urban runoff and this increase in volume causes problems in the runoff collection networks, which are one of the most important infrastructures for urban flood control. In this research, with the help of vulnerability and reliability indicators, the performance of the surface water collection network in the district 10 of Tehran Municipality was evaluated. In this regard, by using SWMM urban flood simulation model, the studied area was simulated hydraulically and hydrologically under the historical precipitation data of Mehrabad synoptic station, then by using vulnerability and reliability indicators, the performance of the network under the return period 2, 5 and 10 years were evaluated. The results indicate that the system vulnerability increases significantly with increasing the return period of the design. Also, the decrease in reliability of system by increasing return period indicates the increase of flood channels.