Sharif Digital Repository

Urbanization and increase in impervious areas owing to building construction, pavements of streets, parking lots and sidewalks, amount of surface runoff in cities has been rose. One of the environmental problems of Tehran during the rainfall is the high polluted runoff flowing in the city and eventually transfers pollution to aquifers. So in order to decline the consequences of this polluted surface runoff, it is crucial to understand how the runoff and pollution form. One way of decreasing pollution in runoff is hiring swales attenuation potential. In this study, problems associated with runoff, particularly in relation to the formation, transformation and removal of pollutants from runoff... 

Urbanization expansion increases impermeable surfaces and ultimately produces more runoff from urban surfaces. The runoff in the urban streets moves the pollution with high levels from the city and then collects into channels where they are transported into the water courses. The most important factor in runoff polluting is sediments. If you remove sediments from runoff, their quality will be improved. One of the effective systems to reduce sediments from the surface runoff is permeable pavement. In this study a simulator system is used. The sample of permeable pavement analysed consisted of two layers of geotextile beddig, filter granular layer (2.36 to 4.75mm), subbase granular layer (4.75... 

Structural best management practices (BMPs) are often used to mitigate the impact of storm water runoff on receiving waters. Vegetative filter strips (VFS) are an example of a structural BMP that has been used to treat storm water and highway runoff. In this study (the first in Iran), field-quality data were collected from a native VFS treating urban runoff in North of Tehran. At first field data were used to test the design concepts of the VFS treatment train and to modify and calibrate simulation model for evaluating the impact of physical factors such as slope, type of vegetation and impermeable surface on sediment removal then more field data were used to evaluate and modify the... 

Urbanization increases impervious surfaces and therefore reduces land permeability. As a result, higher amount of runoff is produced which leads to environmental degradation and economic loss. Use of pervious/permeable pavements is an efficient approach to reduce runoff volume and improve the quality. In this study, different design methods of pervious/permeable surface are first described using structural and hydrological modules. Then, a software program for pervious/permeable surface design is put forth. Supported by various available design methods (focusing on pervious surfaces in Iran), the software employs structural, hydrological, economic (cost estimation) and qualitative... 

Although surface water networks play a very important role in transporting runoff, they contain significant amounts of pollutants entered through the point or non-point sources which cannot be neglected. The goal of this research is quantitative modeling of Zargande reach located in Maghsoodbeyg-Sadr area using SWMM model and investigating the effect of variation of permeable surface on the volume of runoff. Analysis of a 7 hour precipitation with the total of 5 mm cumulative precipitation resulted in 1.6 mm per hour loss of watershed. We utilized a FORTRAN code which minimizes the difference between the Espey synthetic hydrograph and the observed hydrograph for the precipitation to obtain... 

In recent decades, local, regional and national research programs have discovered stormwater runoff as the principal cause of water pollution in most urban areas. To solve urban stormwater runoff problems, we should use revisory measures. This is possible by using Best Management Practices (BMPs). BMPs are innovative technologies to reduce the movement of pollutants from land into surface or groundwaters, in order to protect water quality within natural and economic limitations.Three types of BMPs are discussed in this study; swale, bioretention systems and pond. They have different installation requirements, costs and pollutant removal efficiency. The main objective of this research is to... 

Nowadays, urban storm water management and wastewater reuse are of main concerns of urban managers. Changes in surface specifications such as imperviousness, manning coefficient, pollutant buildup … during catchment transformation of land use from natural to urban can lead to undesirable change in quality and quantity of catchment's outlet runoff that could cause serious damage to receiving bodies. In recent decades, urban designing's approach has been using detention and quality improvement systems in order to manage urban runoff. Urban runoff and its treatment system (BMP: best management practices) and urban lake (as a receiving body) have been modeled in this research. Velenjak stream's... 

With altering natural state and increasing impervious surfaces, traditional urbanization leads to deteriorating the environment and water catchments. During the years most efforts in order to control the urban runoff outflow, have been focused on quantity; and awareness about improving water quality has been raised just in the last few years and, which emphasizes on pollution source control. Standard water quality sampling methods are time consuming, expensive and because of sampling in broad geographic areas, difficult; however modeling is a more efficient way in assessing water quality and as worries about non-point source pollution grows, different kinds of models have been used to...