Hamed Zahedi Khameneh; Saeed Reza Khodashenas
Abstract
In this study, the surface water collection systems of districts 10 and 11 of Mashhad were modeled and evaluated using risk analysis. Sub-basins were also ranked in order to locate the implementation of low impact development (LID) practices. The results showed that although the collection system has ...
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In this study, the surface water collection systems of districts 10 and 11 of Mashhad were modeled and evaluated using risk analysis. Sub-basins were also ranked in order to locate the implementation of low impact development (LID) practices. The results showed that although the collection system has no particular problem with floods with a two- year return period, it does not have a suitable capacity for floods with a higher return period, so that for floods with 5 and 50 years of return period, it has 80 percent discharge capacity of surface runoff and in these year returns, 29.1 and 38.2 percent of the canals, respectively, face waterlogging and back flow.In order to final ranking of the sub-basin for prioritizing the location of LID practices, in addition to risk analysis, the sub-basins were classified based on economic priorities, social conditions and land use. The final ranking that 6.6% of the studied sub-basins, which includes 22.8% of the study area are in groups 4 and 5 (the highest Priority). Ranking puts areas with high flood risk under pressure to accept LID control and make an investment in it, as well as benefits areas where are at lower risk of flooding but are more likely to implement LID practices and invest in them.
Reza Badizadegan; Saeed Reza Khodashenas; Kazem Esmaili
Abstract
In this study SWMM software has been calibrated with real meteorological and hydrometric data at the North of Tehran basins and simulation parameters have been obtained. For this purpose, five rainfall events and runoff data related to these rainfalls, recorded at the outlet of Zargandeh catchment were ...
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In this study SWMM software has been calibrated with real meteorological and hydrometric data at the North of Tehran basins and simulation parameters have been obtained. For this purpose, five rainfall events and runoff data related to these rainfalls, recorded at the outlet of Zargandeh catchment were used. This model is calibrated with three events and verified with two other events. Also, in this simulation the peaks of flood, outflow hydrographs, runoff volumes and peak flood times is obtained. The root mean square error are obtained for outlet hydrographs for the first to fifth events were 0.05, 0.22, 0.4, 0.37 and 0.16, and the Nash-Sutcliffe coefficient are obtained 0.91, 0.94, 0.93, 0.9 and 0.94, respectively. Also, the percentage of difference of the flood discharge peak modeling and observations for first to fifth events are calculated 7.33%, 9.69%, 5.8%, 5.6% and 9.93% and for runoff volume, this percentage difference are calculated -8.82%, -3.08%, 8.8%, -19.43% and 5.11%, respectively. Based on these results, the performance and application of this model to simulate runoff in this area is acceptable and can be used to manage and control urban runoff.