scholarly journals Assessing the Effectiveness and Cost Efficiency of Green Infrastructure Practices on Surface Runoff Reduction at an Urban Watershed in China

Water ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 24
Author(s):  
Fazhi Li ◽  
Jingqiu Chen ◽  
Bernard A. Engel ◽  
Yaoze Liu ◽  
Shizhong Wang ◽  
...  

Studies on the assessment of green infrastructure (GI) practice implementation effect and cost efficiency on an urban watershed scale helps the GI practice selection and investment decisions for sponge city construction in China. However, few studies have been conducted for these topics at present. In this study, the Long-Term Hydrologic Impact Assessment—Low Impact Development (L-THIA-LID) 2.1 model was applied to assess the effectiveness and cost efficiency of GI practices on surface runoff volume reduction in an urban watershed—the Hexi watershed, Nanjing City, China. Grassed swales, bioretentions, green roofs, rain cisterns, permeable pavements, wet ponds, dry ponds, and wetlands were chosen as potential GI practices for sponge city construction based on feasibility analysis. Results showed that grassed swales were the most cost-effective practice (0.7 CNY/m3/yr), but the total implementation effect of grassed swales was not obvious due to the small area of suitable locations. Permeable pavements performed best on runoff reduction, but the cost efficiency was much lower. Correspondingly, bioretentions were compromise practices. Green roofs were the least cost-effective practices, with the cost efficiency at 122.3 CNY/m3/yr, but it was much lower for rain cisterns, which were 3.2 CNY/m3/yr. Wet ponds, dry ponds, and wetlands were potential practices implemented in development areas, of which dry ponds were the most cost-effective (2.7 CNY/m3/yr), followed by wet ponds (10.9 CNY/m3/yr). The annual runoff volume of the total area could be reduced by up to 47.01% by implementing GI practices in buildup areas. Rain cisterns (RC) and permeable pavements (PP) were the best combination for this area, and bioretentions (BR) and green roofs (GR) followed. Grassed swales (GS1), dry ponds (DP), wet ponds (WP), and wetlands (WL) were not wise choices due to the small suitable location areas. This study also demonstrated the feasibility of the L-THIA-LID 2.1 model for the evaluation of GI practice implementation effects and cost efficiency on urban runoff in sponge city construction in China.

2021 ◽  
Author(s):  
Sijie Tang ◽  
Jiping Jiang ◽  
Yi Zheng

<p>Practitioners usually design the plan of Sponge City construction (SCC) by combining LID facilities (e.g., rain garden, rain barrels, green roofs, and grassed swales) according to their personal experiences or general guidelines. The layout (including selection, connection and distribution area) of LID facilities is subjective, in the risk of far from optimal combination. Previous researchers have developed some LID optimization tools, which only consider the dimension and number of LIDs in a given scenario. Therefore, it is necessary to develop a flexible and extensible design tool with the support of urban hydrological model to conduct the facilities layout optimization. This study introduced a SWMM-based multi-variable and multi-objective optimization framework called CAFID (Comprehensive Assessment and Fine Design Model of Sponge City) to meet this end. The assessment module with multi-objective couples diverse controlling end-points (e.g., total runoff, peak runoff, pollutant concentration, cost, and customized social-ecological factors) as the candidates of assessment criteria. The optimization module with multi-variable is implemented by SWMM, starting with three steps: 1) Full allocation. Based on the availability, list the candidates of LID facility for each sub-catchment; 2) Full connection. Order the potential stream direction of surface runoff from rainfall to municipal network, based on possible hierarchical structure of sub-catchments and LID facilities; 3) Full coverage. Identify all the suitable area for LID facility in sub-catchment. The optimization on the 3 variables, the selection, connection, and area, is powered by NSGA-II and TOPSIS algorithms, which make it possible that we choose a final result from the set of nondominated solutions according to special weight distribution. The effectiveness of CAFID was illustrated through a case of Sponge City in Fenghuangcheng of Shenzhen City, one of 30 national pilot sponge cities in China. As well, this new framework is expected to be widely verified and applied in Sponge City construction in China or similar concepts all over the world.</p>


Water ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 3482
Author(s):  
Kun Wang ◽  
Lijun Zhang ◽  
Lulu Zhang ◽  
Shujuan Cheng

Coordinating the “green” and “gray” infrastructure construction and the socioeconomic development is essential to sponge city construction. Most previous research has investigated the structural and non-structural approach for urban water management, such as operational practice, engineered measures, technical solutions, or planning management. However, there is a shortage of strategic management approaches to identify pilot sponge cities, which is essential to cities in developing countries under huge financial pressures. Hence, this paper proposed a coupling coordination evaluation index system to assess the coordination degree between economic development and infrastructure construction in Henan Province in central China. Then, the paper analyzed the differences of the coordination level and its spatial statistical pattern of the coupled and coordinated development of sponge city construction in Henan Province. The results show that: (1) from the perspective of comprehensive level, the problems of inadequate and unbalanced development of infrastructure construction and economic development level are prominent; (2) from the perspective of coordinated development level, the level of coupling and coordination development in Henan Province increased during the sample period, but the level of coupling and coordination development in each region was small; (3) from the perspective of relative development, Zhengzhou City is lagging behind in infrastructure, indicating that economic growth is faster than infrastructure construction, and other regions are lagging economic development, indicating that infrastructure construction is faster than economic growth; and (4) from the spatial statistical analysis, there is spatial positive correlation, that is, the area with high coupling degree of infrastructure construction and economic development level tends to be significantly concentrated in space. Studies have shown that Henan Province should focus on strengthening the construction of “green” infrastructure and increasing the infiltration of the underlying surface to counter the precipitation in urban areas in extreme climates.


Author(s):  
Femin Maria IX ◽  
Elba Helen George

Due to the global climate change and the rapid progress of urbanization, the frequent occurrence of flooding disasters and severe pollution seriously threaten the sustainable development of modern cities. To solve these problems, China first started the construction of the ‘Sponge City’. Sponge city can improve city’s ability to adapt to the environment change and to cope with floods; it can also make them more sustainable. It was not only meant for urban flood control, but also rainwater harvest, ecological restoration of urban land and water quality improvement. The rainfall received in 2020 in Hyderabad of India, has been the highest for the month October in a century. The risk is going to increase year after year in the whole nation. So India too needs a mission that mitigates flood risk and provides a pathway to water security. And the most promising solution across the world at this time can be the idea to adopt Sponge city construction. Improper research in this field will lead to huge maintenance difficulties and other related problems. This paper mainly focuses on presenting the concepts of sponge city construction along with its pathway. Not only does it focus on Sponge city’s benefits, but also its challenges are also stated, which leads to better understanding about its scope of continuing for future. Keywords: Flood control, sponge city, green infrastructure, urban floods.


Water ◽  
2018 ◽  
Vol 10 (2) ◽  
pp. 172 ◽  
Author(s):  
Maochuan Hu ◽  
Xingqi Zhang ◽  
Yim Siu ◽  
Yu Li ◽  
Kenji Tanaka ◽  
...  

10.29007/p6x3 ◽  
2018 ◽  
Author(s):  
Clemens Strehl ◽  
Erle Kristvik ◽  
Juliane Koti

The adaptation of urban water systems to climate change is a complex management challenge. Especially urban drainage systems and their adaptation to growing climate change dynamics, like increasing variations in terms of intensity and frequency of heavy rainfall events, calls for novel adaptation approaches. Growing data availability opens the chance to find suitable cost-effective solutions to tackle climate change risks. In the Damsgård area in Bergen, combined sewer overflows discharge in the fjord during extreme rainfall events. Within the European project BINGO, an evaluation of alternative ways to reduce this environmental pressure is being conducted, using extensive climate, economic and spatial data. The analysis is going to compare different combinations of green infrastructure from the field of water sensitive urban design, like green roofs, ditches and swales. These combinations are furthermore compared with an innovative approach: using the slope of roads as emergency flood water ways.


Author(s):  
Yuyan Fan ◽  
Chengwen Wang ◽  
Haijun Yu ◽  
Junhao Pan ◽  
Zilu Ouyang

2014 ◽  
Vol 41 (6) ◽  
pp. 499 ◽  
Author(s):  
David J. Will ◽  
Karl J. Campbell ◽  
Nick D. Holmes

Context Worldwide, invasive vertebrate eradication campaigns are increasing in scale and complexity, requiring improved decision making tools to achieve and validate success. For managers of these campaigns, gaining access to timely summaries of field data can increase cost-efficiency and the likelihood of success, particularly for successive control-event style eradications. Conventional data collection techniques can be time intensive and burdensome to process. Recent advances in digital tools can reduce the time required to collect and process field information. Through timely analysis, efficiently collected data can inform decision making for managers both tactically, such as where to prioritise search effort, and strategically, such as when to transition from the eradication phase to confirmation monitoring. Aims We highlighted the advantages of using digital data collection tools, particularly the potential for reduced project costs through a decrease in effort and the ability to increase eradication efficiency by enabling explicit data-informed decision making. Methods We designed and utilised digital data collection tools, relational databases and a suite of analyses during two different eradication campaigns to inform management decisions: a feral cat eradication utilising trapping, and a rodent eradication using bait stations. Key results By using digital data collection during a 2-year long cat eradication, we experienced an 89% reduction in data collection effort and an estimated USD42 845 reduction in total costs compared with conventional paper methods. During a 2-month rodent bait station eradication, we experienced an 84% reduction in data collection effort and an estimated USD4525 increase in total costs. Conclusions Despite high initial capital costs, digital data collection systems provide increasing economics as the duration and scale of the campaign increases. Initial investments can be recouped by reusing equipment and software on subsequent projects, making digital data collection more cost-effective for programs contemplating multiple eradications. Implications With proper pre-planning, digital data collection systems can be integrated with quantitative models that generate timely forecasts of the effort required to remove all target animals and estimate the probability that eradication has been achieved to a desired level of confidence, thus improving decision making power and further reducing total project costs.


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