scholarly journals First flush of non-point source pollution and hydrological effects of LID in a Guangzhou community

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Jiajun Zeng ◽  
Guoru Huang ◽  
Haiwan Luo ◽  
Yepeng Mai ◽  
Haichun Wu

Abstract To study the first flush effect of nonpoint source pollution in the Guangzhou community unit, runoff from roads, roofs, and green spaces during three rainfall events was collected and analyzed for pollutants. Nine runoff pollution indices were considered. The dimensionless cumulative curve of pollutant mass vs. volume, the first flush coefficient (b) and the mass first flush ratio (MFFn) were used to assess the first flush effect of different underlying surfaces. The assessment results pointed out that the roof was most prone to first flush effect. And ammonia nitrogen and phosphorus were the main pollutants in the first flush in the study area. For a quantitative analysis of the first flush, the Storm Water Management Model (SWMM) was used to simulate the hydrological effect of low impact development (LID) implementation in the community. The results showed that the first flush strength was reduced after setting LID. And LID measures, such as green roofs and sunken green spaces, contribute to flood control and rainwater purification. This research can be relevant regarding for constructing sponge cities and reducing the pollution caused by the first flush.

Proceedings ◽  
2018 ◽  
Vol 2 (11) ◽  
pp. 640 ◽  
Author(s):  
Ioannis M. Kourtis ◽  
Vassilios A. Tsihrintzis ◽  
Evangelos Baltas

The present work aims at quantifying the benefit of Low Impact Development (LID) practices in reducing peak runoff and runoff volume, and at comparing LID practices to conventional stormwater solutions. The hydrologic-hydraulic model used was the Storm Water Management Model (SWMM5.1). The LID practices modeled were: (i) Green roofs; and (ii) Permeable pavements. Each LID was tested independently and compared to two different conventional practices, i.e., sewer enlargement and detention pond design. Results showed that for small storm events LID practices are comparable to conventional measures, in reducing flooding. Overall, smaller storms should be included in the design process.


2018 ◽  
Vol 18 (9) ◽  
pp. 2525-2536 ◽  
Author(s):  
Jiansheng Wu ◽  
Rui Yang ◽  
Jing Song

Abstract. The increase in impervious surfaces associated with rapid urbanization is one of the main causes of urban inundation. Low-impact development (LID) practices have been studied for mitigation of urban inundation. This study used a hydrodynamic inundation model, coupling SWMM (Storm Water Management Model) and IFMS-Urban (Integrated Flood Modelling System–Urban), to assess the effectiveness of LID under different scenarios and at different hazard levels. The results showed that LID practices can effectively reduce urban inundation. The maximum inundation depth was reduced by 3 %–29 %, average inundation areas were reduced by 7 %–55 %, and average inundation time was reduced by 0 %–43 % under the eight scenarios. The effectiveness of LID practices differed for the three hazard levels, with better mitigation of urban inundation at a low hazard level than at a high hazard level. Permeable pavement (PP) mitigated urban inundation better than green roofs (GRs) under the different scenarios and at different hazard levels. We found that more implementation area with LID was not necessarily more efficient, and the scenario of 10 % PP+10 % GR was more efficient for the study area than other scenarios. The results of this study can be used by local governments to provide suggestions for urban inundation control, disaster reduction, and urban renewal.


2013 ◽  
Vol 68 (1) ◽  
pp. 36-42 ◽  
Author(s):  
E. Burszta-Adamiak ◽  
M. Mrowiec

Green roofs significantly affect the increase in water retention and thus the management of rain water in urban areas. In Poland, as in many other European countries, excess rainwater resulting from snowmelt and heavy rainfall contributes to the development of local flooding in urban areas. Opportunities to reduce surface runoff and reduce flood risks are among the reasons why green roofs are more likely to be used also in this country. However, there are relatively few data on their in situ performance. In this study the storm water performance was simulated for the green roofs experimental plots using the Storm Water Management Model (SWMM) with Low Impact Development (LID) Controls module (version 5.0.022). The model consists of many parameters for a particular layer of green roofs but simulation results were unsatisfactory considering the hydrologic response of the green roofs. For the majority of the tested rain events, the Nash coefficient had negative values. It indicates a weak fit between observed and measured flow-rates. Therefore complexity of the LID module does not affect the increase of its accuracy. Further research at a technical scale is needed to determine the role of the green roof slope, vegetation cover and drying process during the inter-event periods.


2019 ◽  
Vol 20 (1) ◽  
pp. 130-139 ◽  
Author(s):  
Xie Haowen ◽  
Wu Yawen ◽  
Wang Luping ◽  
Luo Weilin ◽  
Zhou Wenqi ◽  
...  

Abstract Green roofs are a sustainable, low-impact development technique. They can reduce peak stormwater runoff and runoff volume and improve the quality of runoff from individual buildings and developments, which can lower the risk of frequent urban flooding and improve the quality of receiving waters. Few studies have compared different types of green roof models under the same rainfall intensities; thus, in this study, the predictions of a non-linear storage reservoirs model, Storm Water Management Model (SWMM), and a physical process model (HYDRUS-1D) were discussed. Both models were compared against measured data obtained from a series of laboratory experiments, designed to represent different storm categories and rainfall events. It was concluded that the total runoff of the SWMM model is always less than that of HYDRUS-1D. The maximum flowrate of the SWMM model is more than that of HYDRUS-1D during all events.


2018 ◽  
Vol 20 (3) ◽  
pp. 588-596 ◽  
Author(s):  
Aviva Gabriel Limos ◽  
Kristine Joy Bernardo Mallari ◽  
Jongrak Baek ◽  
Hwansuk Kim ◽  
Seungwan Hong ◽  
...  

Abstract Green roof is a low impact development (LID) practice used to mitigate imperviousness in urban areas and to reduce flood risks. In order to have sufficient designs and accurate runoff predictions, computer models should be utilized with full understanding of green roofs' hydrologic processes. Evapotranspiration is usually considered important by researchers in the water balance modeling of a green roof. The Storm Water Management Model (SWMM) version 5.1 is widely utilized rainfall-runoff modeling software which has LID controls capable of modeling green roofs. A previous study has evaluated the performance of this model in green roof simulations for single events without considering evapotranspiration in its application, but attained negative outcomes. Thus, the objective of this study is to determine the significance of considering evapotranspiration in producing accurate runoff simulations specifically using SWMM 5.1. The results of this study have shown that when evapotranspiration was not considered, simulations failed to agree with observed values, whereas when evapotranspiration was considered, simulated runoff volumes attained a very good fit with the observed runoff volumes proving the significance of evapotranspiration as an important parameter in green roof modeling.


2018 ◽  
Vol 45 ◽  
pp. 00008 ◽  
Author(s):  
Joanna Bąk

The progressing process of urbanization causes areas that were once previously green to turn into areas with a high rate of runoff. For this reason, all activities aimed at the alternative management of rainwater in the city are extremely important. The aim of the work is to compare the share of rainwater management in urban catchments to various alternative forms of management of these waters (including rain gardens and green roofs). The paper compares the outflows from the sample catchment with different runoff coefficients and after the implementation of various Low Impact Development (LID) practices to the catchment. The calculations were carried out using the Storm Water Management Model (SWMM) program version 5.1.012 with LID controls developed by the United States Environmental Protection Agency (US EPA). The rainfall data used to carry out the simulation was derived over the last three years from the meteorological station in Krakow.


2017 ◽  
Vol 76 (11) ◽  
pp. 3035-3043 ◽  
Author(s):  
Sezar Gülbaz ◽  
Cevza Melek Kazezyılmaz-Alhan

Abstract Recent techniques should be investigated in detail to avoid present and future problems of urbanization like flood, drought and water pollution. Low Impact Development (LID) Best Management Practices (BMPs) such as bioretentions, green roofs, rain barrels, vegetative swales, and permeable pavements have been implemented to diminish the adverse effects of urbanization. In this study, a hydrological model for a Rainfall-Watershed-Bioretention (RWB) system is developed by using the Environmental Protection Agency Storm Water Management Model (EPA SWMM). RWB system is an experimental setup which consists of an artificial rainfall system, a drainage area and four bioretention columns with different soil mixtures. The hydrological modeling capability of SWMM for bioretentions is presented using the experimental data obtained from the experiments conducted in the RWB system under different rainfall events and for bioretentions with different designs. Finally, the modeling results of SWMM are compared with the results of the Hydrological Model of RWB (HM-RWB) system. Results show that EPA SWMM performs well in modeling bioretentions whereas the results of HM-RWB are in better agreement with the experimental data.


2013 ◽  
Vol 68 (6) ◽  
pp. 1315-1321 ◽  
Author(s):  
Jung-min Lee ◽  
Kyoung-hak Hyun ◽  
Jong-soo Choi

An analysis of the impact of a low impact development (LID) on runoff was performed using a Storm Water Management Model 5 (SWMM5)–LID model. The SWMM5 package has been developed to facilitate the analysis of the hydrologic impacts of LID facilities. Continuous simulation of urban stormwater runoff from the district which included the LID design was conducted. In order to examine the impact of runoff in the LID district the first, second and third highest ranked flood events over the past 38 years were analyzed. The assessment estimated that a LID system under historical storm conditions would reduce peak runoff by approximately 55–66% and runoff volume by approximately 25–121% in comparison with that before the LID design. The impact on runoff was also simulated under 50, 80 and 100 year return period conditions. Under these conditions, the runoff reductions within the district were estimated to be about 6–16% (peak runoff) and 33–37% (runoff volume) in comparison with conditions prior to the LID. It is concluded from these results that LID is worthy of consideration for urban flood control in future development and as part of sewer and stormwater management planning.


2019 ◽  
Vol 20 (2) ◽  
pp. 383-394 ◽  
Author(s):  
Jing Peng ◽  
Jiayi Ouyang ◽  
Lei Yu ◽  
Xinchen Wu

Abstract Recently urban waterlogging problems have become more and more serious, and the construction of an airport runway makes the impervious area of the airport high, which leads to the deterioration of the water environment and frequent waterlogging disasters. It is of great significance to design and construct the sponge airport with low impact development (LID) facilities. In this paper, we take catchment N1 of Beijing Daxing International Airport as a case study. The LID facilities are designed and the runoff process of a heavy rainfall in catchment N1 is simulated before and after the implementation of LID facilities. The results show that the total amount of surface runoff, the number of overflow junctions and full-flow conduits of the rainwater drainage system in catchment N1 of Beijing Daxing International Airport are significantly reduced after the implementation of the LID facilities. Therefore, the application of LID facilities has greatly improved the ability of the airport to remove rainwater and effectively alleviated the risk of waterlogging in the airport flight area. This study provides theoretical support for airport designers and managers to solve flood control and rainwater drainage problems and has vital practical significance.


2011 ◽  
Vol 250-253 ◽  
pp. 3392-3396
Author(s):  
Yu Jia Song ◽  
Hui Qing Liu

The discharge of urban sewage and agricultural non-point source pollutants is the main reason causing eutrophication in gullies in most cities of northern China. Based on a careful analysis on the ecological structure and ecological characteristics of a gully, this article preliminarily studies the interception and degradation mechanisms of nitrogen pollutants by the gully. Meanwhile, to take gullies in Changchun as the object of the study, this article carries out an experiment on the interception effect of nitrogen pollutants by gullies. This experiment respectively establishes a control section in the upper and lower reaches of a gully, and takes water samples four times in each section from May to August to determine total nitrogen, total phosphorus, nitrate nitrogen, ammonia nitrogen and salinity. The result shows: the gully plays some role in the interception of pollutants; total phosphorus accounts for the largest interception in pollutants in the experimented gully section, with the relative interception rate of 27.46%, followed by ammonia nitrogen, with the interception rate of 21.80%, which is the result of the combined effects of aquatic plants, microorganisms and sediment in the gully.


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