Analysis of Sustainability Index in Stormwater Drainage Systems under the Climate Change Impacts (Case Study: District 11 of Tehran)

Assessment of the effects of climate change on hydrological processes especially urban floods to adapt and modify its effects, is essential. In this study, the impact of climate change on the extreme rainfall in district 1 zone 11 of Tehran during the period 2020-2049 was investigated by using 10 AOGCM models under two scenarios including Rcp2.6 and Rcp8.5. Then a median scenario was considered as an aggregate of the results of all the above mentioned climatic models, and by using the SWMM software, the function of sub drainage system of the region in the current and future situations was examined in the future. Finally the function of network evaluated by using the performance indexes contains reliability, resiliency, vulnerability and sustainability. To simulate flooding of the area, a precipitation with a 5 and 10 years of return period was used. The results of simulation indicate that in the current situation a total of %38.2 and in future conditions about %40 of the length of the canals in the area will be flooded. The sustainability index of the network was also investigated under the influence of precipitation. The sustainability of the drainage system in the region was %72.79 in the present condition and the future under the scenario Rcp2.6, and Rcp8.5 were %71.06 and %72.78 respectively. Generally, it was found that in the future period under the influence of both climate change scenarios the flood volume and the number of flooding points will not increase significantly compared to the current situation.