scholarly journals Optimal Planning of Low-Impact Development for TSS Control in the Upper Area of the Cau Bay River Basin, Vietnam

Water ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 533 ◽  
Author(s):  
Dang Minh Hai

Recently, an increase in impervious area induced by the process of urbanization has significantly affected the quantity and quality of urban surface runoff. Among the pollutants of the storm flow, total suspended solids (TSS) are an extremely important cause of water quality deterioration. This paper aims to use the integrated nondominated sorting genetic algorithm (NSGA II)–Storm Water Management Model (SWMM) method to find optimal Low-Impact Development (LID) plans which ensure maximum TSS load reduction and minimum total relative cost. Green roofs, permeable pavements, and tree boxes with fixed parameters and unit costs were considered for seeking optimal planning alternatives in the Cau Bay river basin. The optimization process yielded a cost–effectiveness curve, which relates cost of LID implementation with its corresponding TSS reduction efficiencies. The advantage of the optimization approach was clarified when, with a defined cost of LID implementation, there was a significant difference in TSS reduction efficiencies between the optimal and non-optimal alternatives. The increase in return periods of rainfall patterns not only resulted in a reduction in the TSS removal efficiencies of LID practices at the outfall of the study area, but also spatially changed in terms of the TSS removal efficiencies of the sub-catchments. The return period of the rainfall patterns utilized for LID design should not exceed 2 years. The simulation–multi-optimization approach facilitates integration of LID practice plans into the urban infrastructure master plans in Vietnam.

2021 ◽  
Author(s):  
Xiang Feng Hong

<p>Due to the expansion of the urban area increases the impervious area and Inhibits the influence of evapotranspiration and infiltration of the water cycle. In addition, climate change causes extreme rainfall events, increase rainfall have greatly increased surface runoff in cities, Increase the intensity and depth of rainfall. These have led to a substantial increase in surface runoff in cities.</p><p>Green roof is one of the low-impact development measures. This study will improve the above-mentioned problems through the rainfall retention characteristics of green roofs, Calculate peak flow reduction and delay of arrival time. We have built a green roof observation system which including experimental group (green roof) and control group (no green roof) to obtain various observational data of the water cycle. Then input the data into the surface hydrological model for calibration and validation to analyze the retention characteristics of green roofs. Evaluate the flood reduction effect of green roofs in Taiwan.</p>


2007 ◽  
Vol 2 (2) ◽  
Author(s):  
William C. Lucas

Retaining rainfall where it lands is a fundamental benefit of Low Impact Development (LID). The Delaware Urban Runoff Management Model (DURMM) was developed to address the benefits of LID design. DURMM explicitly addresses the benefits of impervious area disconnection as well as swale flow routing that responds to flow retardance changes. Biofiltration swales are an effective LID BMP for treating urban runoff. By adding check dams, the detention storage provided can also reduce peak rates. This presentation explores how the DURMM runoff reduction approach can be integrated with detention routing procedures to project runoff volume and peak flow reductions provided by BMP facilities. This approach has been applied to a 1,200 unit project on 360 hectares located in Delaware, USA. Over 5 km of biofiltration swales have been designed, many of which have stone check dams placed every 30 to 35 meters to provide detention storage. The engineering involved in the design of such facilities uses hydrologic modeling based upon TR-20 routines, as adapted by the DURMM model. The hydraulic approach includes routing of flows through the check dams. This presentation summarizes the hydrological network, presents the hydrologic responses, along with selected hydrographs to demonstrate the potential of design approach.


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.


2014 ◽  
Vol 70 (4) ◽  
pp. 671-677 ◽  
Author(s):  
Xiaomin Ji ◽  
Youpeng Xu ◽  
Longfei Han ◽  
Liu Yang

Stream structure is usually dominated by various human activities over a short term. An analysis of variation in stream structure from 1979 to 2009 in the Qinhuai River Basin, China, was performed based on remote sensing images and topographic maps by using ArcGIS. A series of river parameters derived from river geomorphology are listed to describe the status of river structure in the past and present. Results showed that urbanization caused a huge increase in the impervious area. The number of rivers in the study area has decreased and length of rivers has shortened. Over the 30 years, there was a 41.03% decrease in river length. Complexity and stability of streams have also changed and consequently the storage capacities of river channels in intensively urbanized areas are much lower than in moderately urbanized areas, indicating a greater risk of floods. Therefore, more attention should be paid to the urban disturbance to rivers.


2021 ◽  
Vol 26 (2) ◽  
pp. 36
Author(s):  
Alejandro Estrada-Padilla ◽  
Daniela Lopez-Garcia ◽  
Claudia Gómez-Santillán ◽  
Héctor Joaquín Fraire-Huacuja ◽  
Laura Cruz-Reyes ◽  
...  

A common issue in the Multi-Objective Portfolio Optimization Problem (MOPOP) is the presence of uncertainty that affects individual decisions, e.g., variations on resources or benefits of projects. Fuzzy numbers are successful in dealing with imprecise numerical quantities, and they found numerous applications in optimization. However, so far, they have not been used to tackle uncertainty in MOPOP. Hence, this work proposes to tackle MOPOP’s uncertainty with a new optimization model based on fuzzy trapezoidal parameters. Additionally, it proposes three novel steady-state algorithms as the model’s solution process. One approach integrates the Fuzzy Adaptive Multi-objective Evolutionary (FAME) methodology; the other two apply the Non-Dominated Genetic Algorithm (NSGA-II) methodology. One steady-state algorithm uses the Spatial Spread Deviation as a density estimator to improve the Pareto fronts’ distribution. This research work’s final contribution is developing a new defuzzification mapping that allows measuring algorithms’ performance using widely known metrics. The results show a significant difference in performance favoring the proposed steady-state algorithm based on the FAME methodology.


Water ◽  
2015 ◽  
Vol 7 (11) ◽  
pp. 6204-6227 ◽  
Author(s):  
José Valencia ◽  
Ana Tarquis ◽  
Antonio Saa ◽  
María Villeta ◽  
José Gascó

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.


Water ◽  
2018 ◽  
Vol 10 (10) ◽  
pp. 1446 ◽  
Author(s):  
Juanhui Ren ◽  
Ji Liang ◽  
Bo Ren ◽  
Xiuqing Zheng ◽  
Chaofan Guo

This paper aims to gain a better understanding of urban river pollution through evaluation of water quality. Data for 10 parameters at eight sites of the Tongzhou Section of the Beiyun River (TSBR) are analyzed. Hierarchical cluster analysis, fuzzy comprehensive assessment, discriminant analysis and Spearman’s correlation analysis were used to estimate the water situation of each cluster and analyze its spatial-temporal variations. Principal component analysis/factor analysis were applied to extract and recognize the sources responsible for water-quality variations. The results showed that temporal variation is greater than spatial and sewage discharge is the dominant factor of the seasonal distribution. Moreover, during the rapid-flow period, water quality is polluted by a combination of organic matter, phosphorus, bio-chemical pollutants and nitrogen; during the gentle-flow period, water quality is influenced by domestic and industrial waste, the activities of algae, aquatic plants and phosphorus pollution. In regard to future improvement of water quality in TSBR, the control of reclaimed wastewater from adjacent factories should first be put in place, as well as other techniques, for example, an increase of the impervious area, low-impact development, and integrated management practices should also be proposed in managing storm water runoff.


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.


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