In the search for space-efficient nature-based solutions (NBS) for stormwater management, we designed a vertical greenery system (VGS) for enhanced evapotranspiration (ET). After assessing a range of construction options, an 80 m long and 3.2 m high freestanding stormwater-VGS, referred to as the Green Climate Screen (GCS), was constructed in 2019 in Copenhagen. The GCS receives runoff from 240 m2 of roof top and has a high ratio of surface-to-ground area to allow for the clothesline effect to enhance ET. The conveyance of runoff to the top of the GCS is based on gravitational force. It is estimated that 24 h events with return periods up to the 0.1 y (13.9 mm) are managed by ET, from 0.1 to 15 y (48.5 mm) by infiltration beneath the screen, and from 15 to >100 y by overflow to an adjacent area allowing for aboveground storage (167 mm), in total 229 mm. With the fulfillment of most performance criteria and successful inclusion of selected co-benefits ET-based stormwater, NBS could become future standard elements. To reduce CO2 and resource footprint, steel, concrete, and mineral wool must be replaced with renewable materials. Adaptation to more spatial contexts is encouraged.
为了寻找空间高效的基于自然的雨水管理解决方案(NBS)，我们设计了一个垂直绿化系统(VGS)来增强蒸散发(ET)。在评估了一系列施工方案后，一个80米长、3.2米高的独立式雨水vgs，被称为绿色气候屏幕(GCS)，于2019年在哥本哈根建成。GCS接收来自240平方米屋顶的径流，其地面与地面面积的比例很高，允许晾衣绳效应增强ET。径流向GCS顶部的输送基于重力。据估计，24小时的事件，其返回周期高达0.1 y (13.9 mm)，由ET管理，从0.1到15 y (48.5 mm)通过渗透到屏幕下，从15到100 y通过溢出到相邻区域，允许地上储存(167 mm)，总共229 mm。随着大多数性能标准的实现和基于排放当量的雨水的选定协同效益的成功纳入，NBS可能成为未来的标准要素。为了减少二氧化碳和资源足迹，钢铁、混凝土和矿棉必须用可再生材料代替。鼓励适应更多的空间环境。
{"title":"Into the air: a freestanding vertical greenery system (VGS) for evapotranspiration (ET) of roof runoff","authors":"Emilia Danuta Lausen, M. B. Jensen, M. Randall","doi":"10.2166/bgs.2022.029","DOIUrl":"https://doi.org/10.2166/bgs.2022.029","url":null,"abstract":"\u0000 In the search for space-efficient nature-based solutions (NBS) for stormwater management, we designed a vertical greenery system (VGS) for enhanced evapotranspiration (ET). After assessing a range of construction options, an 80 m long and 3.2 m high freestanding stormwater-VGS, referred to as the Green Climate Screen (GCS), was constructed in 2019 in Copenhagen. The GCS receives runoff from 240 m2 of roof top and has a high ratio of surface-to-ground area to allow for the clothesline effect to enhance ET. The conveyance of runoff to the top of the GCS is based on gravitational force. It is estimated that 24 h events with return periods up to the 0.1 y (13.9 mm) are managed by ET, from 0.1 to 15 y (48.5 mm) by infiltration beneath the screen, and from 15 to >100 y by overflow to an adjacent area allowing for aboveground storage (167 mm), in total 229 mm. With the fulfillment of most performance criteria and successful inclusion of selected co-benefits ET-based stormwater, NBS could become future standard elements. To reduce CO2 and resource footprint, steel, concrete, and mineral wool must be replaced with renewable materials. Adaptation to more spatial contexts is encouraged.","PeriodicalId":9337,"journal":{"name":"Blue-Green Systems","volume":null,"pages":null},"PeriodicalIF":4.6,"publicationDate":"2022-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41481884","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Lays Paulino Leonel, Ariane Bize, M. Mariadassou, C. Midoux, Jerusa Schneider, A. L. Tonetti
For agricultural reuse, the disinfection treatment must be efficient to inactivate the resistant pathogens and must not generate harmful byproducts for the soil and crop production. Thus, the aim of this work was to evaluate the possible impacts caused by the irrigation with wastewater disinfected with sodium hypochlorite, peracetic acid, ultraviolet radiation, or the oxidation process UV radiation combined with hydrogen peroxide over soil physicochemical properties and microbial community composition, as well as over the wheat crop yield in the short term. A pot essay was performed in a greenhouse, and at the end the main alterations observed in soil physicochemical properties were due to water type, not to the disinfection treatments. The crop yield was influenced by the water type, but not by the disinfectant treatments. Irrigation with wastewater improved almost 5 times the wheat grains yield, compared with freshwater. Wastewater irrigation increased the abundance of families involved in organic matter degradation and nitrogen cycle, and some pathogenic bacteria. Among the disinfectant treatments, the UV disinfection played an important role in shaping soil bacterial community structure.
{"title":"Impacts of disinfected wastewater irrigation on soil characteristics, microbial community composition, and crop yield","authors":"Lays Paulino Leonel, Ariane Bize, M. Mariadassou, C. Midoux, Jerusa Schneider, A. L. Tonetti","doi":"10.2166/bgs.2022.126","DOIUrl":"https://doi.org/10.2166/bgs.2022.126","url":null,"abstract":"\u0000 For agricultural reuse, the disinfection treatment must be efficient to inactivate the resistant pathogens and must not generate harmful byproducts for the soil and crop production. Thus, the aim of this work was to evaluate the possible impacts caused by the irrigation with wastewater disinfected with sodium hypochlorite, peracetic acid, ultraviolet radiation, or the oxidation process UV radiation combined with hydrogen peroxide over soil physicochemical properties and microbial community composition, as well as over the wheat crop yield in the short term. A pot essay was performed in a greenhouse, and at the end the main alterations observed in soil physicochemical properties were due to water type, not to the disinfection treatments. The crop yield was influenced by the water type, but not by the disinfectant treatments. Irrigation with wastewater improved almost 5 times the wheat grains yield, compared with freshwater. Wastewater irrigation increased the abundance of families involved in organic matter degradation and nitrogen cycle, and some pathogenic bacteria. Among the disinfectant treatments, the UV disinfection played an important role in shaping soil bacterial community structure.","PeriodicalId":9337,"journal":{"name":"Blue-Green Systems","volume":null,"pages":null},"PeriodicalIF":4.6,"publicationDate":"2022-12-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45231993","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M. Winker, Jutta Deffner, Michael Rohrbach, Engelbert Schramm, Melina Stein
Enhancing blue-green infrastructure (BGI) will help cities adapt to climate change. This study focused on urban society, specifically on residents, the housing and real estate sector, and municipal administration in the cities of Frankfurt and Stuttgart, and investigated ways to enhance BGI in line with their perceptions, expectations and requirements. A particular emphasis was placed on periods of hot, dry weather. During future workshops, actor analysis, expert interviews and two expert workshops, the positions, level of knowledge and attitudes of the various groups were examined and barriers to BGI identified, in addition to discussions about measures to overcome these barriers. The results showed that within urban society the greatest support for BGI comes from residents, followed by municipal employees, while actors in the housing and real estate sector are the most reluctant. It became evident that there is a need for action to overcome a range of barriers. Overall, political backing, alliances between stakeholders, encouragement of the housing and real estate sector to take action, and a focus on initiating action in selected urban areas are recommended for successful enhancement of BGI. To ensure maximum impact, there should also be a combination of bottom-up and top-down activities.
{"title":"Enhancing blue-green infrastructure in German cities with the involvement of urban society: insights from Frankfurt/Main and Stuttgart","authors":"M. Winker, Jutta Deffner, Michael Rohrbach, Engelbert Schramm, Melina Stein","doi":"10.2166/bgs.2022.017","DOIUrl":"https://doi.org/10.2166/bgs.2022.017","url":null,"abstract":"\u0000 Enhancing blue-green infrastructure (BGI) will help cities adapt to climate change. This study focused on urban society, specifically on residents, the housing and real estate sector, and municipal administration in the cities of Frankfurt and Stuttgart, and investigated ways to enhance BGI in line with their perceptions, expectations and requirements. A particular emphasis was placed on periods of hot, dry weather. During future workshops, actor analysis, expert interviews and two expert workshops, the positions, level of knowledge and attitudes of the various groups were examined and barriers to BGI identified, in addition to discussions about measures to overcome these barriers. The results showed that within urban society the greatest support for BGI comes from residents, followed by municipal employees, while actors in the housing and real estate sector are the most reluctant. It became evident that there is a need for action to overcome a range of barriers. Overall, political backing, alliances between stakeholders, encouragement of the housing and real estate sector to take action, and a focus on initiating action in selected urban areas are recommended for successful enhancement of BGI. To ensure maximum impact, there should also be a combination of bottom-up and top-down activities.","PeriodicalId":9337,"journal":{"name":"Blue-Green Systems","volume":null,"pages":null},"PeriodicalIF":4.6,"publicationDate":"2022-12-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41689962","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
V. Prodanovic, B. Hatt, Harsha S Fowdar, Mohammed Al-Ameri, A. Deletic
Stormwater biofilters are one of the most widely used nature-based solutions for urban water management. In the last 20 years, biofilters have been extensively studied for their pollutant removal performance; however, their application in the field is limited by high maintenance requirements. In this work, we propose the concept of zero additional maintenance (ZAM) biofilters as a solution to this challenge. To understand the design and operation of ZAM biofilters, a three-stage research programme was conducted to (i) examine filter media configurations that could protect against surface clogging, (ii) test the pollutant removal performance of a variety of lawn grasses, and (iii) validate the laboratory findings through field monitoring. The results showed that a protective filter media layer delayed the onset of clogging. Five lawn grasses – Kenda Kikuyu, Empire Zoysia, Santa Ana Couch, Village Green Kikuyu and Palmetto Soft Leaf Buffalo – were found to effectively reduce nitrogen concentrations and meet other local pollution reduction requirements. Monitoring of three field-scale ZAM biofilters confirmed their high nutrient and heavy metal removal performance. Overall, the findings of these three studies confirm the potential for well-designed ZAM biofilters to achieve stormwater management requirements with no additional maintenance compared with standard street landscaping.
雨水生物过滤器是应用最广泛的基于自然的城市水管理解决方案之一。在过去的20年里，生物过滤器的污染物去除性能得到了广泛的研究；然而，它们在现场的应用受到高维护要求的限制。在这项工作中，我们提出了零额外维护（ZAM）生物过滤器的概念，作为解决这一挑战的方案。为了了解ZAM生物过滤器的设计和操作，进行了一个三阶段的研究计划，以（i）检查可以防止表面堵塞的过滤介质配置，（ii）测试各种草坪草的污染物去除性能，以及（iii）通过现场监测验证实验室的发现。结果表明，保护性过滤介质层延缓了堵塞的发生。五种草坪草——Kenda Kikuyu、Empire Zoysia、Santa Ana Couch、Village Green Kikuyu和Palmetto Soft Leaf Buffalo——被发现可以有效降低氮浓度，并满足当地其他减少污染的要求。对三个现场规模的ZAM生物滤池的监测证实了它们的高营养和重金属去除性能。总的来说，这三项研究的结果证实，与标准街道景观相比，设计良好的ZAM生物滤池有潜力在无需额外维护的情况下实现雨水管理要求。
{"title":"Zero additional maintenance stormwater biofilters: from laboratory testing to field implementation","authors":"V. Prodanovic, B. Hatt, Harsha S Fowdar, Mohammed Al-Ameri, A. Deletic","doi":"10.2166/bgs.2022.030","DOIUrl":"https://doi.org/10.2166/bgs.2022.030","url":null,"abstract":"\u0000 Stormwater biofilters are one of the most widely used nature-based solutions for urban water management. In the last 20 years, biofilters have been extensively studied for their pollutant removal performance; however, their application in the field is limited by high maintenance requirements. In this work, we propose the concept of zero additional maintenance (ZAM) biofilters as a solution to this challenge. To understand the design and operation of ZAM biofilters, a three-stage research programme was conducted to (i) examine filter media configurations that could protect against surface clogging, (ii) test the pollutant removal performance of a variety of lawn grasses, and (iii) validate the laboratory findings through field monitoring. The results showed that a protective filter media layer delayed the onset of clogging. Five lawn grasses – Kenda Kikuyu, Empire Zoysia, Santa Ana Couch, Village Green Kikuyu and Palmetto Soft Leaf Buffalo – were found to effectively reduce nitrogen concentrations and meet other local pollution reduction requirements. Monitoring of three field-scale ZAM biofilters confirmed their high nutrient and heavy metal removal performance. Overall, the findings of these three studies confirm the potential for well-designed ZAM biofilters to achieve stormwater management requirements with no additional maintenance compared with standard street landscaping.","PeriodicalId":9337,"journal":{"name":"Blue-Green Systems","volume":null,"pages":null},"PeriodicalIF":4.6,"publicationDate":"2022-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49546742","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Sara Maria Lerer, Alexandre Hallkvist Guidje, Karin Margrethe Löf Drenck, Camilla Christiane Jakobsen, K. Arnbjerg-Nielsen, P. Mikkelsen, H. J. Sørup
Stormwater control measures (SCMs) are effective and sustainable complementary means of managing stormwater in cities. Unlike underground drainage systems, they require space on the city surface, and therefore must be included in initial sketches of urban planning and design. These initial sketches are often made by architects and urban planners, who are usually not trained in hydrology, and therefore require simple and robust tools to inform their initial plans with respect to stormwater management. There may be local guidelines for dimensioning SCMs, but their applicability is often limited with regard to the range of SCMs, and the methodology behind them may be oversimplified, including a lack of assessment of benefits on the urban hydrological cycle. We developed a methodology for estimating multiple performance indicators of a wide range of SCMs and applied it to Danish meteorological conditions. The methodology includes consulting expected end users, configuring an SWMM model for each SCM type and choosing applicable parameter ranges, running multiple simulations for each type covering the parameter space, and post-processing the results using python and PySWMM. The outputs can be used to draw general recommendations regarding effective application ranges for different SCMs, and to quickly assess the performance of case-specific configurations.
{"title":"Constructing an inventory for fast screening of hydraulic and hydrologic performance of stormwater control measures","authors":"Sara Maria Lerer, Alexandre Hallkvist Guidje, Karin Margrethe Löf Drenck, Camilla Christiane Jakobsen, K. Arnbjerg-Nielsen, P. Mikkelsen, H. J. Sørup","doi":"10.2166/bgs.2022.018","DOIUrl":"https://doi.org/10.2166/bgs.2022.018","url":null,"abstract":"\u0000 Stormwater control measures (SCMs) are effective and sustainable complementary means of managing stormwater in cities. Unlike underground drainage systems, they require space on the city surface, and therefore must be included in initial sketches of urban planning and design. These initial sketches are often made by architects and urban planners, who are usually not trained in hydrology, and therefore require simple and robust tools to inform their initial plans with respect to stormwater management. There may be local guidelines for dimensioning SCMs, but their applicability is often limited with regard to the range of SCMs, and the methodology behind them may be oversimplified, including a lack of assessment of benefits on the urban hydrological cycle. We developed a methodology for estimating multiple performance indicators of a wide range of SCMs and applied it to Danish meteorological conditions. The methodology includes consulting expected end users, configuring an SWMM model for each SCM type and choosing applicable parameter ranges, running multiple simulations for each type covering the parameter space, and post-processing the results using python and PySWMM. The outputs can be used to draw general recommendations regarding effective application ranges for different SCMs, and to quickly assess the performance of case-specific configurations.","PeriodicalId":9337,"journal":{"name":"Blue-Green Systems","volume":null,"pages":null},"PeriodicalIF":4.6,"publicationDate":"2022-11-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44741191","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
J. Langeveld, F. Cherqui, F. Tscheikner-Gratl, T. Muthanna, M. F. Juárez, J. Leitão, B. Roghani, Karsten Kerres, Maria do Céu Almeida, C. Werey, B. Rulleau
Urban drainage systems have developed way beyond the traditional piped combined or separate sewer systems. Many ‘new’ systems are being introduced, ranging from stormwater infiltration facilities to green roofs. However, the widely advocated blue-green infrastructures are typically overlooked by asset managers, which will very likely have detrimental effects on their performance, service life, and wider adoption. In this paper, the working group on Urban Drainage Asset Management (UDAM – https://udam.home.blog/) of the IWA and IAHR Joint Committee on Urban Drainage discusses whether the state-of-the-art knowledge based on conventional sewer asset management is sufficient to develop asset management for blue-green infrastructures (BGIs). The discussion is structured around the five preconditions for effective control and asset management. Results show that asset management for BGIs is still underdeveloped due to a lack of monitoring techniques covering the broad range of BGI benefits and performance indicators, inspection techniques covering relevant failure mechanisms and models describing these mechanisms, maintenance and rehabilitation options, and sufficient support tools to aid inhabitants in the operation and maintenance of their individual BGIs such as green roofs or vegetated swales.
{"title":"Asset management for blue-green infrastructures: a scoping review","authors":"J. Langeveld, F. Cherqui, F. Tscheikner-Gratl, T. Muthanna, M. F. Juárez, J. Leitão, B. Roghani, Karsten Kerres, Maria do Céu Almeida, C. Werey, B. Rulleau","doi":"10.2166/bgs.2022.019","DOIUrl":"https://doi.org/10.2166/bgs.2022.019","url":null,"abstract":"\u0000 Urban drainage systems have developed way beyond the traditional piped combined or separate sewer systems. Many ‘new’ systems are being introduced, ranging from stormwater infiltration facilities to green roofs. However, the widely advocated blue-green infrastructures are typically overlooked by asset managers, which will very likely have detrimental effects on their performance, service life, and wider adoption. In this paper, the working group on Urban Drainage Asset Management (UDAM – https://udam.home.blog/) of the IWA and IAHR Joint Committee on Urban Drainage discusses whether the state-of-the-art knowledge based on conventional sewer asset management is sufficient to develop asset management for blue-green infrastructures (BGIs). The discussion is structured around the five preconditions for effective control and asset management. Results show that asset management for BGIs is still underdeveloped due to a lack of monitoring techniques covering the broad range of BGI benefits and performance indicators, inspection techniques covering relevant failure mechanisms and models describing these mechanisms, maintenance and rehabilitation options, and sufficient support tools to aid inhabitants in the operation and maintenance of their individual BGIs such as green roofs or vegetated swales.","PeriodicalId":9337,"journal":{"name":"Blue-Green Systems","volume":null,"pages":null},"PeriodicalIF":4.6,"publicationDate":"2022-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45543268","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Elhadi Mohsen Hassan Abdalla, T. Muthanna, K. Alfredsen, E. Sivertsen
The common approach of the hydrologic design of permeable pavements (PPs) uses synthetic rainfall events. This study assessed the validity of the design approach using synthetic rainfall events for undrained PP. Synthetic rainfall events (25-year return period) were used to design undrained pavements for five Norwegian cities. The effectiveness of these pavements was tested using long-term simulation (12–30 years) with high temporal resolution (1 min). The Storm Water Management Model (SWMM) was used to generate time series of surface runoff for PPs and flow duration curves were applied to analyse the hydrological performances. Designing PP using synthetic rainfall events was found to underestimate the storage layer depth of the permeable pavements leading to the frequent occurrence of surface runoff, which is considered a failure of the hydrologic design of undrained pavements. Long-term simulation of surface runoff was found to provide valuable information for the hydrologic design of PP and can be used as a basis for the PP hydrologic design. In the future, it is recommended to use long-term precipitation data generated from climate change models to incorporate the effect of climate change in the design of PP.
{"title":"Towards improving the hydrologic design of permeable pavements","authors":"Elhadi Mohsen Hassan Abdalla, T. Muthanna, K. Alfredsen, E. Sivertsen","doi":"10.2166/bgs.2022.004","DOIUrl":"https://doi.org/10.2166/bgs.2022.004","url":null,"abstract":"\u0000 The common approach of the hydrologic design of permeable pavements (PPs) uses synthetic rainfall events. This study assessed the validity of the design approach using synthetic rainfall events for undrained PP. Synthetic rainfall events (25-year return period) were used to design undrained pavements for five Norwegian cities. The effectiveness of these pavements was tested using long-term simulation (12–30 years) with high temporal resolution (1 min). The Storm Water Management Model (SWMM) was used to generate time series of surface runoff for PPs and flow duration curves were applied to analyse the hydrological performances. Designing PP using synthetic rainfall events was found to underestimate the storage layer depth of the permeable pavements leading to the frequent occurrence of surface runoff, which is considered a failure of the hydrologic design of undrained pavements. Long-term simulation of surface runoff was found to provide valuable information for the hydrologic design of PP and can be used as a basis for the PP hydrologic design. In the future, it is recommended to use long-term precipitation data generated from climate change models to incorporate the effect of climate change in the design of PP.","PeriodicalId":9337,"journal":{"name":"Blue-Green Systems","volume":null,"pages":null},"PeriodicalIF":4.6,"publicationDate":"2022-11-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43484655","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Green roofs are a popular way to include nature in an urban environment. A reduction in stormwater runoff peaks and volumes are among the benefits one can expect. How is runoff from green roofs in the cold and snow-covered part of the year, when growth media freeze, plants are dormant and covered with melting snow? This paper investigates 11 years of runoff from three green extensive roofs in Oslo, Norway. Precipitation through the snow-covered period (SCP) was approximately one-third of the annual precipitation (970 mm). When runoff from green roofs is compared to runoff from a non-vegetated bitumen roof, retention of 16–31% is seen through the SCP, depending on the drainage system, fabric, soil quality, and depth. The difference in buildup did not influence the detention of the largest runoff intensities. Dampening the runoff happened even though the substrate was saturated. According to the soil moisture sensors, the capacity of the roof with the highest water retention could be increased even more if drainage could be restricted. The runoff from bitumen roofs always exceeded the runoff from green roofs. As a result, harmful inundation may be reduced in a part of the year when infiltration is restricted due to frost.
{"title":"Retention of snowmelt and rain from extensive green roofs during snow-covered periods","authors":"B. Braskerud, K. Paus","doi":"10.2166/bgs.2022.011","DOIUrl":"https://doi.org/10.2166/bgs.2022.011","url":null,"abstract":"\u0000 Green roofs are a popular way to include nature in an urban environment. A reduction in stormwater runoff peaks and volumes are among the benefits one can expect. How is runoff from green roofs in the cold and snow-covered part of the year, when growth media freeze, plants are dormant and covered with melting snow? This paper investigates 11 years of runoff from three green extensive roofs in Oslo, Norway. Precipitation through the snow-covered period (SCP) was approximately one-third of the annual precipitation (970 mm). When runoff from green roofs is compared to runoff from a non-vegetated bitumen roof, retention of 16–31% is seen through the SCP, depending on the drainage system, fabric, soil quality, and depth. The difference in buildup did not influence the detention of the largest runoff intensities. Dampening the runoff happened even though the substrate was saturated. According to the soil moisture sensors, the capacity of the roof with the highest water retention could be increased even more if drainage could be restricted. The runoff from bitumen roofs always exceeded the runoff from green roofs. As a result, harmful inundation may be reduced in a part of the year when infiltration is restricted due to frost.","PeriodicalId":9337,"journal":{"name":"Blue-Green Systems","volume":null,"pages":null},"PeriodicalIF":4.6,"publicationDate":"2022-11-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45271060","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Water distribution networks (WDNs) are an important part of water distribution systems and are responsible for water transportation from the reservoirs to the demand nodes at adequate pressure and velocity. In the present paper, the synthesis of WDN is treated as an optimization problem with a mixed integer nonlinear programming formulation. The objective function to be minimized is the total network cost, considering installation and energy costs, with unknown flow directions, which is the novelty in the paper. Disjunctive programming and linearization techniques are used in the model formulation to avoid nonlinear and nonconvex problems. Two case studies are used to test the model's applicability. Results show that operational costs can represent a significant part of the total cost in sustainable networks. In the first case study, the total cost was better than the literature results (US$ 2,272,538.85 vs. US$ 2,272,387.49) and the operational costs represent ¼ of the total WDN costs. In the second case study, the operation cost corresponds to almost 2/3 of the total WDN cost. These results show the importance of considering operational costs in the WDN design. Also, the consideration of unknown flow directions can lead to better results for the network topology.
{"title":"Optimization of installation and energy costs in water distribution systems with unknown flow directions","authors":"G. Cassiolato, E. Carvalho, M. Ravagnani","doi":"10.2166/bgs.2022.003","DOIUrl":"https://doi.org/10.2166/bgs.2022.003","url":null,"abstract":"\u0000 Water distribution networks (WDNs) are an important part of water distribution systems and are responsible for water transportation from the reservoirs to the demand nodes at adequate pressure and velocity. In the present paper, the synthesis of WDN is treated as an optimization problem with a mixed integer nonlinear programming formulation. The objective function to be minimized is the total network cost, considering installation and energy costs, with unknown flow directions, which is the novelty in the paper. Disjunctive programming and linearization techniques are used in the model formulation to avoid nonlinear and nonconvex problems. Two case studies are used to test the model's applicability. Results show that operational costs can represent a significant part of the total cost in sustainable networks. In the first case study, the total cost was better than the literature results (US$ 2,272,538.85 vs. US$ 2,272,387.49) and the operational costs represent ¼ of the total WDN costs. In the second case study, the operation cost corresponds to almost 2/3 of the total WDN cost. These results show the importance of considering operational costs in the WDN design. Also, the consideration of unknown flow directions can lead to better results for the network topology.","PeriodicalId":9337,"journal":{"name":"Blue-Green Systems","volume":null,"pages":null},"PeriodicalIF":4.6,"publicationDate":"2022-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49134803","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Blue-green and blue roofs are increasingly promoted to adapt to climate change by providing multiple benefits. However, uncertainties about their design and how they differ from conventional green roofs hinder their implementation. This study investigates the potential of green, blue-green, and blue roofs to control urban stormwater and improve microclimate by monitoring their performance in Toronto, Ontario, Canada. Experimental setups were built and varied with the following design factors: substrate type and thickness, drainage layer thickness and orifice size. The results revealed that blue-green roofs with organic and FLL (blended according to the German Forschungsgesellschaft Landschaftsentiwicklung Landschaftsbau) substrates significantly improved detention compared to green roofs with similar substrates. The organic blue-green roof achieved maximum retention, but FLL blue-green roof did not have higher retention than FLL green roof. The blue roof with smaller orifices had comparable hydrologic performance to vegetated roofs but suffered from long water standing durations. Organic substrates followed by FLL substrates result in the highest air cooling in the noon, but blue roofs had the highest air cooling in the evening. In-substrate temperatures in blue-green roofs were lower than those in green roofs. Trade-offs between the benefits and drawbacks need to be considered in future designs.
{"title":"Impact of design variables on hydrologic and thermal performance of green, blue-green and blue roofs","authors":"Tamer Almaaitah, J. Drake, D. Joksimovic","doi":"10.2166/bgs.2022.016","DOIUrl":"https://doi.org/10.2166/bgs.2022.016","url":null,"abstract":"\u0000 Blue-green and blue roofs are increasingly promoted to adapt to climate change by providing multiple benefits. However, uncertainties about their design and how they differ from conventional green roofs hinder their implementation. This study investigates the potential of green, blue-green, and blue roofs to control urban stormwater and improve microclimate by monitoring their performance in Toronto, Ontario, Canada. Experimental setups were built and varied with the following design factors: substrate type and thickness, drainage layer thickness and orifice size. The results revealed that blue-green roofs with organic and FLL (blended according to the German Forschungsgesellschaft Landschaftsentiwicklung Landschaftsbau) substrates significantly improved detention compared to green roofs with similar substrates. The organic blue-green roof achieved maximum retention, but FLL blue-green roof did not have higher retention than FLL green roof. The blue roof with smaller orifices had comparable hydrologic performance to vegetated roofs but suffered from long water standing durations. Organic substrates followed by FLL substrates result in the highest air cooling in the noon, but blue roofs had the highest air cooling in the evening. In-substrate temperatures in blue-green roofs were lower than those in green roofs. Trade-offs between the benefits and drawbacks need to be considered in future designs.","PeriodicalId":9337,"journal":{"name":"Blue-Green Systems","volume":null,"pages":null},"PeriodicalIF":4.6,"publicationDate":"2022-09-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41389252","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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