Amir Hossein Sovizi, Rojin hemati
The low impact development best management practices (LID-BMPs) method have proved the ability to runoff controlling and reduction in recent years, But the little of research has focused on the effective factors on LID control’s performance such as average slope, area of study, types of soil, the number of LID control in sub-catchment, etc. That’s why this article presents an evaluation of the effect of area slope on rain garden performance. The results of this article demonstrate the amount of flow frequency percentage, average flow, maximum flow, total volume, and total TSS in normal slope conditions are respectively equal to 75.35%, 0.361 in/m, 0.837 in/m, 7.341liters and 5.982 kg, and with ten percentage increasing slope of the area, the amount of flow frequency percentage, average flow, maximum flow, total volume and total Tss will be equal to 76.61%, 0.365 in/m, 0.837 in/m, 7.332 liters, and 6.014 kg. according to these results the amount of slope is effective on runoff quality than other indicators.
Keywords: LID-BMPs – runoff – flow frequency – TSS – runoff quality
By recognizing the effective factors on the performance of LID controls and also evaluating these factors the approach of making the most of LID controls can be realized. The LID-BMPs method controlled the amount of runoff and also the runoff quality improved. These two abilities can solve the problem of lack of drinking water and also the problem of urban floods. For this reason, a number of researches focused on water quality using LID-BMPs method that for example, Chang et al in 2008 formed a model by using EPA SWMM for two industrial parks in Taiwan in order to correlate the relationship between pollutant mass and the runoff volume . Sezar GÜLBAZ et al. in 2014 investigated the impact of “LID-BMP” on surface runoff and TSS by employing a calibrated hydrodynamic model for Sazlıdere Watershed which is located in Istanbul, Turkey . Aslam Hanief and Andrew E. Laursen in 2019 used from best management practices in order to reduction of phosphorus in rivers . Ratino Sith et al in 2019 evaluated water quality and evaluation of best management practices in a small agricultural watershed adjacent to Coral Reef area in Japan . Marina Batalini de Macedo et al in 2019 evaluated the behavior of a bioretention cell in a Brazilian city, during the dry period, which is critical in terms of pollutant accumulation and water availability . In recent years the more articles were about runoff reduction and controlling as example, Meysam Kamali et al. in 2017 Evaluated permeable pavement responses to urban surface runoff . Yaoze Liu et al. in 2016 presented Optimal selection and placement of BMPs and LID practices with a rainfall-runoff model . Zhihua zhu et al. in 2019 provided an assessment of the hydrologic effectiveness of low impact development (LID)practices for managing runoff with different objectives . HwansukKim et al. in 2019 considered the effect of groundwater on bioretention using the storm water management model . Haifeng jia et al in 2013 presented advances in LID BMPs research and practice for urban runoff control in China . Damodaram et al. in 2010 demonstrate that use of LID practices yields significant stormwater control for small events and less control for flood events for a watershed located on the campus of Texas A&M University, Texas . Chang et al in 2008 formed a model by using EPA SWMM for two industrial parks in Taiwan in order to correlate the relationship between pollutant mass and the runoff volume . Jia et al. in 2012 combine and compare LIDs with other stormwater BMPs for urban runoff control and reduction in the Beijing Olympic Village residential area of China . Gill et al. in 2007 find LID to be effective in moderating potential climate change impacts such as extreme temperatures and increased surface runoff in urban areas of Greater Manchester, U.K. LID techniques . Alexander Engebretsen et al. in 2019 decreased phosphorus loading by agricultural Best Management Practices . Yu Wang et al in 2019 analyzed the cost-effectiveness of BMPs implementation and their impacts on reducing nonpoint source pollution in the source area of the Liao River . Yepeng Mai et al. in 2018 effects of LID measures on the control of rainfall runoff . Qian Li et al. in 2019 considered a comprehensive performance evaluation of LID practices for the sponge city construction . Negin Binesh et al. in 2019 introduced a new definition of urban drainage system (UDS) sustainability, focusing on BMP usage to enhance system performance after adaptation to climate change . Pyke et al. in 2011 suggested that stormwater runoff is most sensitive to changes in site impervious cover, followed by changes in precipitation volume under climate change impacts and event intensity in south Boston, Massachusetts . Finally, this article presented an effect evaluation of slope on rain garden performance.