Urban floods have adverse impacts on the performance of urban infrastructures and the life of residents. The floods cause heavy damages and perturbation in the serviceability of urban infrastructures as well as transportation. Therefore, different factors affecting the urban water flood characteristics should be considered in urban development planning, especially in metropolitan areas. In recent years, climate change and its consequences have affected the total components of the water cycle as well as floods. These effects are intensified in urban areas because of the anthropogenic effects they have on the water cycle, such as reducing the infiltration capacity of basins, construction regardless of the channel’s right of way, and disposal of sediment and solid wastes into channels that will decrease the channels’ safe carrying capacity. In this way, incorporating climate change impact on urban water studies could help to achieve more reliable results to be applied in real-time planning of urban areas thr...

Drought is a natural phenomenon that occurs in many places on the planet and may cause considerable damage. Selection of an integrated index for quantifying drought severity is a challenge for decision makers in developing water resources and operation management policies. In this study, the standardized precipitation index, water surface supply index, and Palmer drought severity index have been combined to develop an integrated index, called the hybrid drought index (HDI), using associated damage of drought events. Application of the HDI in drought severity prediction has been examined using two different types of artificial neural networks, namely, a probabilistic neural network and a multilayer perceptron network. These models have been selected due to their special characteristics that are suitable for prediction schemes. The proposed algorithm for developing HDI and drought prediction has been applied to the “Gavkhooni/Zayandeh-rud” basin in the central part of Iran. The results show the merits of ea...

Research has revealed the impacts of climate change on the hydrologic cycle. These impacts are intensified in the urban water system due to special characteristics of urban watersheds, such as a high percentage of impervious areas and the presence of a microclimate. A slight change in rainfall intensity and duration can cause severe floods, with a significant incremental increase in life and property losses. Therefore, it is a key issue to modify the urban watershed characteristics in a systematic way to deal with these probable changes. In this paper, a multicriteria optimization model is developed to select best management practices (BMPs) for flood management in urban watershed systems. The addressed criteria include maximizing reliability of the drainage system, as well as minimizing flood damages and BMP costs. A new reliability index for dealing with floods is suggested in this study that considers both severity and duration of flooding. The optimization model is solved using a two-stage mul...

Life-cycle assessment (LCA) was applied to assess the environmental impacts of a wastewater treatment plant (WWTP), along with 20 tertiary treatment options for reuse in agricultural irrigation, artificial recharge of groundwater, and industrial usages. Impact $2002+$ was adopted as the life-cycle impact assessment method. The results indicate that the energy consumed by the equipment accounts for 66.59% of environmental impacts of the WWTP. Moreover, consumption of the electricity generated by local biogas generators, instead of using the Iranian national grid, can be beneficial in mitigating the environmental impacts of the WWTP in the form of avoided impacts. LCA showed that a depth filter, granular activated carbon, and chlorination; a membrane bioreactor and chlorination; ultrafiltration, reverse osmosis, and chlorination; and ultrafiltration, reverse osmosis, a depth filter, coagulation/flocculation, and chlorination had the lowest environmental impacts for reuse in agricultural irrigation, artificial recharge of groundwater, cooling towers and other industries, and boilers, respectively. Energy consumption of tertiary treatment technologies is the primary contributor to the environmental impacts. This study indicated that because of high electricity and chemical consumption of the options for reuse in industries, their environmental impacts are higher than those of other options.