WorldWideScience

Sample records for m2 green roof

  1. Green roofs

    CSIR Research Space (South Africa)

    Van Wyk, Llewellyn V

    2010-04-01

    Full Text Available Green roofs are roofs that have been covered with a growing medium, creating a habitat on what would otherwise be a bland, lifeless surface. It is for this reason that green roofs are sometimes call 'vegetated' or 'living' roofs (Cantor 2008). A...

  2. Green Roofs

    Energy Technology Data Exchange (ETDEWEB)

    None

    2004-08-01

    A New Technology Demonstration Publication Green roofs can improve the energy performance of federal buildings, help manage stormwater, reduce airborne emissions, and mitigate the effects of urban heat islands.

  3. Green roof Malta

    OpenAIRE

    2015-01-01

    In Malta, buildings cover one third of the Island, leaving greenery in the dirt track. Green roofs are one way to bring plants back to urban areas with loads of benefits. Antoine Gatt, who manages the LifeMedGreenRoof project at the University of Malta, tells us more. http://www.um.edu.mt/think/green-roof-malta/

  4. EPA's Green Roof Research

    Science.gov (United States)

    This is a presentation on the basics of green roof technology. The presentation highlights some of the recent ORD research projects on green roofs and provices insight for the end user as to the benefits for green roof technology. It provides links to currently available EPA re...

  5. Green Roofs for Stormwater Management

    Science.gov (United States)

    This project evaluated green roofs as a stormwater management tool. Results indicate that the green roofs are capable of removing 40% of the annual rainfall volume from a roof through retention and evapotranspiration. Rainfall not retained by green roofs is detained, effectively...

  6. Green roofs; Les toitures vegetalisees

    Energy Technology Data Exchange (ETDEWEB)

    Seghier, C.

    2006-03-15

    Impervious surface coverage keeps spreading in cities. Streets, sidewalks, parking lots and roofs are waterproof, meaning greater amounts of water to channel and treat and higher flood risks during heavy rainfalls. Green roofing can play a key part in addressing this alarming issue. There are three types of green roofs: extensive, semi-intensive and intensive. The extensive green roof technique uses a thin soil covering with a variety of species providing year-round plant coverage. The plants are not necessarily horticultural in which case routine maintenance is minimal. No watering is needed. Usually extensive green roofs create an ecosystem. The semi-intensive green roof technique uses a soil covering of average thickness and serves to create decorative roofing. Although maintenance is moderate, watering is essential. The intensive green roof technique produces a terrace roof garden. Another advantage of green roofs is they increase the life cycle of the sealing. Roof sealing protection may see the span of its life cycle, now at about fifteen years, doubled if the building has a green roof. planning professionals still know very little about green roofing solutions. Yet, green roofing provides unquestionable ecological qualities and thermal and acoustic performance that have proven to be environmentally friendly. Yet France lags behind northern European countries in green roofing. The Germans, Swiss, Austrians, Scandinavians and Dutch have been using the technique for more than twenty years. (A.L.B.)

  7. Green Roofs for Stormwater Runoff Control - Abstract

    Science.gov (United States)

    This project evaluated green roofs as a stormwater management tool. Specifically, runoff quantity and quality from green and flat asphalt roofs were compared. Evapotranspiration from planted green roofs and evaporation from unplanted media roofs were also compared. The influence...

  8. Carbon sequestration potential of extensive green roofs.

    Science.gov (United States)

    Getter, Kristin L; Rowe, D Bradley; Robertson, G Philip; Cregg, Bert M; Andresen, Jeffrey A

    2009-10-01

    Two studies were conducted with the objective of quantifying the carbon storage potential of extensive green roofs. The first was performed on eight roofs in Michigan and four roofs in Maryland, ranging from 1 to 6 years in age. All 12 green roofs were composed primarily of Sedum species, and substrate depths ranged from 2.5 to 12.7 cm. Aboveground plant material was harvested in the fall of 2006. On average, these roofs stored 162 g C x m(-2) in aboveground biomass. The second study was conducted on a roof in East Lansing, MI. Twenty plots were established on 21 April 2007 with a substrate depth of 6.0 cm. In addition to a substrate only control, the other plots were sown with a single species of Sedum (S. acre, S. album, S. kamtshaticum, or S. spurium). Species and substrate depth represent typical extensive green roofs in the United States. Plant material and substrate were harvested seven times across two growing seasons. Results at the end of the second year showed that aboveground plant material storage varied by species, ranging from 64 g C x m(-2) (S. acre) to 239 g C x m(-2) (S. album), with an average of 168 g C x m(-2). Belowground biomass ranged from 37 g C x m(-2) (S. acre) to 185 g C x m(-2) (S. kamtschaticum) and averaged 107 g C x m(-2). Substrate carbon content averaged 913 g C x m(-2), with no species effect, which represents a sequestration rate of 100 g C x m(-2) over the 2 years of this study. The entire extensive green roof system sequestered 375 g C x m(-2) in above- and belowground biomass and substrate organic matter.

  9. Analysis on thermal measuring of green roof

    Institute of Scientific and Technical Information of China (English)

    唐鸣放; 蒋琳

    2009-01-01

    Comparison of thermal performance between a green roof room and a bare roof room was presented during the cooling period in Shanghai. The results show that the electricity can be saved about 0.08 kW·h/(d·m2),and the heat flux can be reduced by about 70%; the inner surface temperature variation is about 1.0 ℃ comparing with the indoor temperature when using the green roof,and the extra equivalent heat resistance is 1.0 m2·K/W.

  10. Stormwater Attenuation by Green Roofs

    Science.gov (United States)

    Sims, A.; O'Carroll, D. M.; Robinson, C. E.; Smart, C. C.

    2014-12-01

    Innovative municipal stormwater management technologies are urgently required in urban centers. Inadequate stormwater management can lead to excessive flooding, channel erosion, decreased stream baseflows, and degraded water quality. A major source of urban stormwater is unused roof space. Green roofs can be used as a stormwater management tool to reduce roof generated stormwater and generally improve the quality of runoff. With recent legislation in some North American cities, including Toronto, requiring the installation of green roofs on large buildings, research on the effectiveness of green roofs for stormwater management is important. This study aims to assess the hydrologic response of an extensive sedum green roof in London, Ontario, with emphasis on the response to large precipitation events that stress municipal stormwater infrastructure. A green roof rapidly reaches field capacity during large storm events and can show significantly different behavior before and after field capacity. At field capacity a green roof has no capillary storage left for retention of stormwater, but may still be an effective tool to attenuate peak runoff rates by transport through the green roof substrate. The attenuation of green roofs after field capacity is linked to gravity storage, where gravity storage is the water that is temporarily stored and can drain freely over time after field capacity has been established. Stormwater attenuation of a modular experimental green roof is determined from water balance calculations at 1-minute intervals. Data is used to evaluate green roof attenuation and the impact of field capacity on peak flow rates and gravity storage. In addition, a numerical model is used to simulate event based stormwater attenuation. This model is based off of the Richards equation and supporting theory of multiphase flow through porous media.

  11. Green roofs: potential at LANL

    Energy Technology Data Exchange (ETDEWEB)

    Pacheco, Elena M [Los Alamos National Laboratory

    2009-01-01

    Green roofs, roof systems that support vegetation, are rapidly becoming one of the most popular sustainable methods to combat urban environmental problems in North America. An extensive list of literature has been published in the past three decades recording the ecological benefits of green roofs; and now those benefits have been measured in enumerated data as a means to analyze the costs and returns of green roof technology. Most recently several studies have made substantial progress quantifying the monetary savings associated with storm water mitigation, the lessoning of the Urban Heat Island, and reduction of building cooling demands due to the implementation of green roof systems. Like any natural vegetation, a green roof is capable of absorbing the precipitation that falls on it. This capability has shown to significantly decrease the amount of storm water runoff produced by buildings as well as slow the rate at which runoff is dispensed. As a result of this reduction in volume and velocity, storm drains and sewage systems are relieved of any excess stress they might experience in a storm. For many municipalities and private building owners, any increase in storm water mitigation can result in major tax incentives and revenue that does not have to be spent on extra water treatments. Along with absorption of water, vegetation on green roofs is also capable of transpiration, the process by which moisture is evaporated into the air to cool ambient temperatures. This natural process aims to minimize the Urban Heat Island Effect, a phenomenon brought on by the dark and paved surfaces that increases air temperatures in urban cores. As the sun distributes solar radiation over a city's area, dark surfaces such as bitumen rooftops absorb solar rays and their heat. That heat is later released during the evening hours and the ambient temperatures do not cool as they normally would, creating an island of constant heat. Such excessively high temperatures induce heat

  12. Hydrological Performance of Green Roofs

    OpenAIRE

    Poorova, Zuzana; Vranayova, Zuzana

    2015-01-01

    There should be a balance between artificial environment and natural environment. As forests, fields, gardens and urban lands are being replaced with bituminous, concrete and unnatural surfaces, necessity of recovering green and blue spaces and natural areas is becoming more and more critical. Green roof is a tool in strategy of making more pervious areas and beating more impervious areas. Green roof is lately becoming part of urban storm water management. Considering this fact, new construct...

  13. Green Roofs and Green Building Rating Systems

    OpenAIRE

    Liaw; Chao-Hsien

    2015-01-01

    The environmental benefits for green building from the Leadership in Energy and Environment Design (LEED) and Ecology, Energy, Waste, and Health (EEWH) rating systems have been extensively investigated; however, the effect of green roofs on the credit-earning mechanisms is relatively unexplored. This study is concerned with the environmental benefits of green roofs with respect to sustainability, stormwater control, energy savings, and water resources. We focused on the relationsh...

  14. Green Roofs and Green Building Rating Systems

    Directory of Open Access Journals (Sweden)

    Liaw

    2015-01-01

    Full Text Available The environmental benefits for green building from the Leadership in Energy and Environment Design (LEED and Ecology, Energy, Waste, and Health (EEWH rating systems have been extensively investigated; however, the effect of green roofs on the credit-earning mechanisms is relatively unexplored. This study is concerned with the environmental benefits of green roofs with respect to sustainability, stormwater control, energy savings, and water resources. We focused on the relationship between green coverage and the credits of the rating systems, evaluated the credits efficiency, and performed cost analysis. As an example, we used a university building in Keelung, Northern Taiwan. The findings suggest that with EEWH, the proposed green coverage is 50–75%, whereas with LEED, the proposed green coverage is 100%. These findings have implications for the application of green roofs in green building.

  15. Green Roofs for Stormwater Runoff Control

    Science.gov (United States)

    This project evaluated green roofs as a stormwater management tool. Specifically, runoff quantity and quality from green and flat asphalt roofs were compared. Evapotranspiration from planted green roofs and evaporation from unplanted media roofs were also compared. The influence...

  16. Green Roof Potential in Arab Cities

    OpenAIRE

    Attia, Shady

    2014-01-01

    Urban green roofs have long been promoted as an easy and effective strategy for beautifying the built environment and increasing investment opportunity. The building roof is very important because it has a direct impact on thermal comfort and energy conservation in and around buildings. Urban green roofs can help to address the lack of green space in many urban areas. Urban green roofs provides the city with open spaces that helps reduce urban heat island effect and provides the human populat...

  17. GREEN ROOFS — A GROWING TREND

    Science.gov (United States)

    One of the most interesting stormwater control systems under evaluation by EPA are “green roofs”. Green roofs are vegetative covers applied to building roofs to slow, or totally absorb, rainfall runoff during storms. While the concept of over-planted roofs is very ancient, the go...

  18. Future oriented and more sustainable green roofs

    Energy Technology Data Exchange (ETDEWEB)

    Appl, R.; Ansel, W. [Deutscher Dachgartnerverband, Nuertingen (Germany)

    2004-07-01

    The contribution that green roofs make to sustainable urban Development were discussed with reference to the support that the industry has received in Germany. The German Roof Gardener Association (DDV) was established in the 1990s with an objective to replace the billions of square feet of bare or gravel flat roof surface area in Germany with ecological green roofs. The DDV created guidelines for the systems and components being used in green roof constructions, starting from the raw material to the production and transport of the material, and to the recycling of the material after demolition. Green roofs in Germany are now made mandatory by local authorities. Green roofs offer innovative technological features as well as additional use. Combined with extensive or intensive greening, these roofs reduce the use of building land. They must be built to last the lifetime of the building and given proper care and maintenance. In the twenty-first century, green roof systems will be made of recycled and environmentally sound material. The purpose of the green roof is to provide not only a permanent location for vegetation, but also offer further possibilities of utilization, such as additional thermal insulation, fall protection systems or even constructions for solar power facilities. This paper addressed issues regarding the extended life expectancy of a roof, savings on stormwater tax and thermal values for insulation calculations. Green roofs in Germany currently represent an important element in stormwater management by slowing down, filtering and diminishing rain water runoff. The excess water is guided into cisterns and used for the irrigation of the roof gardens and for flushing toilets. 5 figs.

  19. Green roofs provide habitat for urban bats

    Directory of Open Access Journals (Sweden)

    K.L. Parkins

    2015-07-01

    Full Text Available Understanding bat use of human-altered habitat is critical for developing effective conservation plans for this ecologically important taxon. Green roofs, building rooftops covered in growing medium and vegetation, are increasingly important conservation tools that make use of underutilized space to provide breeding and foraging grounds for urban wildlife. Green roofs are especially important in highly urbanized areas such as New York City (NYC, which has more rooftops (34% than green space (13%. To date, no studies have examined the extent to which North American bats utilize urban green roofs. To investigate the role of green roofs in supporting urban bats, we monitored bat activity using ultrasonic recorders on four green and four conventional roofs located in highly developed areas of NYC, which were paired to control for location, height, and local variability in surrounding habitat and species diversity. We then identified bat vocalizations on these recordings to the species level. We documented the presence of five of nine possible bat species over both roof types: Lasiurus borealis, L. cinereus, L. noctivagans, P. subflavus,andE. fuscus. Of the bat calls that could be identified to the species level, 66% were from L. borealis. Overall levels of bat activity were higher over green roofs than over conventional roofs. This study provides evidence that, in addition to well documented ecosystem benefits, urban green roofs contribute to urban habitat availability for several North American bat species.

  20. Factors Influencing Arthropod Diversity on Green Roofs

    Directory of Open Access Journals (Sweden)

    Bracha Y. Schindler

    2011-01-01

    Full Text Available Green roofs have potential for providing substantial habitat to plants, birds, and arthropod species that are not well supported by other urban habitats. Whereas the plants on a typical green roof are chosen and planted by people, the arthropods that colonize it can serve as an indicator of the ability of this novel habitat to support a diverse community of organisms. The goal of this observational study was to determine which physical characteristics of a roof or characteristics of its vegetation correlate with arthropod diversity on the roof. We intensively sampled the number of insect families on one roof with pitfall traps and also measured the soil arthropod species richness on six green roofs in the Boston, MA area. We found that the number of arthropod species in soil, and arthropod families in pitfall traps, was positively correlated with living vegetation cover. The number of arthropod species was not significantly correlated with plant diversity, green roof size, distance from the ground, or distance to the nearest vegetated habitat from the roof. Our results suggest that vegetation cover may be more important than vegetation diversity for roof arthropod diversity, at least for the first few years after establishment. Additionally, we found that even green roofs that are small and isolated can support a community of arthropods that include important functional groups of the soil food web.

  1. Extensive Green Roof Ecological Benefits in Latvia

    OpenAIRE

    Rušenieks, Rihards; Kamenders, Agris

    2013-01-01

    Extensive green roof ecological benefits are studiedin this paper. The research contains a brief explanation aboutgreen roof technology and green roof ecological benefits. Greenroof capability to retain rainwater runoff by accumulating it instorage layers and conducting it back into the atmospherethrough evapotranspiration is studied and modeled. Modeling isdone in Stormwater Management Model 5.0 software. The modelis based on an existing warehouse-type building located in Rigaand hourly Riga...

  2. [A review of green roof performance towards management of roof runoff].

    Science.gov (United States)

    Chen, Xiao-ping; Huang, Pei; Zhou, Zhi-xiang; Gao, Chi

    2015-08-01

    Green roof has a significant influence on reducing runoff volume, delaying runoff-yielding time, reducing the peak flow and improving runoff quality. This paper addressed the related research around the world and concluded from several aspects, i.e., the definition of green roof of different types, the mechanism how green roof manages runoff quantity and quality, the ability how green roof controls roof runoff, and the influence factors of green roof toward runoff quantity and quality. Afterwards, there was a need for more future work on research of green roof toward roof runoff, i.e., vegetation selection of green roof, efficient construction model selection of green roof, the regulating characteristics of green roof on roof runoff, the value assessment of green roof on roof runoff, analysis of source-sink function of green roof on the water pollutants of roof runoff and the research on the mitigation measures of roof runoff pollution. This paper provided a guideline to develop green roofs aiming to regulating roof runoff.

  3. Thermal insulation performance of green roof systems

    Energy Technology Data Exchange (ETDEWEB)

    Celik, Serdar; Morgan, Susan; Retzlaff, William; Once, Orcun [southern Illinois University (United States)], e-mail: scelik@siue.edu, e-mail: smorgan@siue.edu, e-mail: wretzla@siue.edu, e-mail: oonce@siue.edu

    2011-07-01

    With the increasing costs of energy, good building insulation has become increasingly important. Among existing insulation techniques is the green roof system, which consists of covering the roof of a building envelop with plants. The aim of this paper is to assess the impact of vegetation type and growth media on the thermal performance of green roof systems. Twelve different green roof samples were made with 4 different growth media and 3 sedum types. Temperature at the sample base was recorded every 15 minutes for 3 years; the insulation behavior was then analysed. Results showed that the insulation characteristics were achieved with a combination of haydite and sedum sexangulare. This study demonstrated that the choice of growth media and vegetation is important to the green roof system's performance; further research is required to better understand the interactions between growth media and plant roots.

  4. Six aspects to inspirational green roof design

    Energy Technology Data Exchange (ETDEWEB)

    Kiers, H. [SWA Group, Sausalito, CA (United States)

    2004-07-01

    Green roofs have been categorized as a technology that is not initially faster, better or cheaper, and may even under perform established products. However, green roofs have features and values that early adopters are ready to experiment with in small markets, thereby creating awareness of the technology. Termed as disruptive technologies, green roofs can become competitive within the mainstream market against established products. The challenge in green roof construction is to find the correct balance between idealistic principles and leading edge design. This paper presented case studies to examine the following 6 aspects of design fundamentals to the creation of inspirational green roofs: the use of colour; experimentation with materials and technology; incorporation of texture, form, and pattern; definition of space; engagement of vistas; and, principles of bio-regionalism. It was concluded that good design is not enough to lead to widespread green roof implementation. It was emphasized that change will occur primarily because of the benefits acquired through implementation. 11 refs., 7 figs.

  5. Metal and nutrient dynamics on an aged intensive green roof.

    Science.gov (United States)

    Speak, A F; Rothwell, J J; Lindley, S J; Smith, C L

    2014-01-01

    Runoff and rainfall quality was compared between an aged intensive green roof and an adjacent conventional roof surface. Nutrient concentrations in the runoff were generally below Environmental Quality Standard (EQS) values and the green roof exhibited NO3(-) retention. Cu, Pb and Zn concentrations were in excess of EQS values for the protection of surface water. Green roof runoff was also significantly higher in Fe and Pb than on the bare roof and in rainfall. Input-output fluxes revealed the green roof to be a potential source of Pb. High concentrations of Pb within the green roof soil and bare roof dusts provide a potential source of Pb in runoff. The origin of the Pb is likely from historic urban atmospheric deposition. Aged green roofs may therefore act as a source of legacy metal pollution. This needs to be considered when constructing green roofs with the aim of improving pollution remediation.

  6. An Integrative Analysis of an Extensive Green Roof System: A Case Study of the Schleman Green Roof

    Science.gov (United States)

    Hoover, F.; Bowling, L. C.

    2013-12-01

    In urban environments where populations continue to rise, the need for affective stormwater management and runoff control methods is ever prevalent. Increased population growth and city expansion means greater impervious surfaces and higher rates of stormwater runoff. In well-established cities, this proves particularly difficult due to a constraining built environment and limited pervious spaces, even in cities as small as 40,000 residents. Work to reduce runoff in combined sewer systems (CSS) and municipal separated storm sewer systems (MS4) by use of best-management practices is one route currently under investigation. The Purdue University campus is making efforts to reduce their impact on the West Lafayette CSS and MS4. Green roofs are one management practice being used for runoff mitigation. Specifically, Schleman Hall, an administrative student affairs building, has a small green roof located on the second floor installed in 2008. In cooperation with Purdue Physical Facilities, monitoring and analysis for the Schleman extensive green roof at Purdue University was performed from June 2012 to December 2012. The objective was to determine the stormwater retention, output water quality and net present value for the 165 m2 roof. The results from the water balance analysis revealed retention rates on average of 58% of precipitation per rain event, where retention included soil moisture, evaporation and detention/depression storage. The water quality metrics tested were Nitrate-Nitrite (NO2-NO3), Orthophosphate (PO4), Ammonia-Ammonium ion (NH3-NH4), Sulfate (SO4), total suspended solids (TSS) and pH. The pollutant concentration and load results varied, but the pH levels from precipitation increased in all samples after passing through the substrate. SO4 and PO4 results yielded higher concentrations and loads in the green roof output than the control output and precipitation, while NO2-NO3 and NH3-NH4 yielded concentrations and loads that were reduced by the green

  7. Green roofs and the LEED green building rating system

    Energy Technology Data Exchange (ETDEWEB)

    Kula, R. [Sustainable Solutions Inc., Wagoner, OK (United States)

    2005-07-01

    The sustainable building industry is becoming increasingly aware of the host of public and private benefits that green roofs can provide in built environments. In dense urban environments, green roofs function to reduce stormwater runoff, urban heat island effects, and particulate matter (PM) pollution. The emerging green roof industry is now poised to support the efforts of green building networks in North America. This paper discussed the general benefits of green roofs, and their recognition within the Leadership in Energy and Environmental Design (LEED) Green Building Rating System. A case study of Mountain Equipment Co-op's Winnipeg site was presented. The building's green roof was directly responsible for earning 5 credits and contributing to the achievement of an additional 2 credits under the LEEDS certification process. Credits were earned for reduced site disturbance; landscape design to reduce heat islands; and water efficiency. The green roof at the site provided the vast majority of the building's cooling needs through an evaporative cooling trough. A photovoltaic pump was used to feed the building's irrigation system, as well as to pump ground water through cooling valances. It was concluded that the rise of sustainable building practices and the LEED Green Building Rating System will revolutionize the way new buildings are constructed.

  8. Retention capacity of extensive green roofs

    Directory of Open Access Journals (Sweden)

    Sobczyk Małgorzata

    2016-09-01

    Full Text Available Climate change causes a more frequent occurrence of extreme events. The result of these phenomena is the occurrence of floods and flooding, and periods of drought. Particularly unfavorable is intensive rainfall over the urban catchments. To prevent the negative consequences of these phenomena, unconventional solutions should be used. The use of green roofs in urban areas will serve the sustainable development of cities and the impact on local ecological changes. The study was performed at two green roof platforms 1.2×1.2×0.1 m each. An analysis was performed at different intensities given for precipitation. 20 min for the rain to stop was observed from 68 to 100% precipitation. The study was divided into two parts. The first part of the study has been performed in the dry period. In contrast, another round of tests was repeated in other conditions after rainfall. The amount of water at two experimental green roofs platforms before the test was 11.0 dm3. The research relates to the impact of green roofs on local hydrological changes. Development of technologies for green roofs had a positive impact on mitigating the effects of climate change associated with the occurrence of flooding the city.

  9. Experimental Heat Transfer Study on Green Roofs in a Semiarid Climate during Summer

    Directory of Open Access Journals (Sweden)

    Roy J. Issa

    2015-01-01

    Full Text Available An experimental study was conducted on green roofs under the semiarid summer climatic conditions of West Texas to investigate the effect of soil type, moisture content, and the presence of a top soil grass layer on the conductive heat transfer through the roof. Two soil types were investigated: uniform sand and local silt clay. Tests were also conducted on a control roof. A dual-needle heat-pulse sensor was used to conduct thermal property tests on the soils. The tests reveal that unlike sand, the thermal conductivity of silt clay did not increase continuously with soil moisture. Better heat transfer conditions were achieved when the sand and silt clay roofs were watered to a water depth of 10 mm per day rather than double the amount of 20 mm per day. The roof with silt clay soil had the lowest fluctuation in inner temperature between daytime and nighttime. Green roofs with silt clay soil required more than twice the amount of soil moisture than green roofs with sand to achieve similar roof heat transfer rates. The best net heat flux gains for vegetated green roofs were 4.7 W/m2 for the sand roof and 7.8 W/m2 for the silt clay roof.

  10. Green roof valuation: a probabilistic economic analysis of environmental benefits.

    Science.gov (United States)

    Clark, Corrie; Adriaens, Peter; Talbot, F Brian

    2008-03-15

    Green (vegetated) roofs have gained global acceptance as a technologythat has the potential to help mitigate the multifaceted, complex environmental problems of urban centers. While policies that encourage green roofs exist atthe local and regional level, installation costs remain at a premium and deter investment in this technology. The objective of this paper is to quantitatively integrate the range of stormwater, energy, and air pollution benefits of green roofs into an economic model that captures the building-specific scale. Currently, green roofs are primarily valued on increased roof longevity, reduced stormwater runoff, and decreased building energy consumption. Proper valuation of these benefits can reduce the present value of a green roof if investors look beyond the upfront capital costs. Net present value (NPV) analysis comparing a conventional roof system to an extensive green roof system demonstrates that at the end of the green roof lifetime the NPV for the green roof is between 20.3 and 25.2% less than the NPV for the conventional roof over 40 years. The additional upfront investment is recovered at the time when a conventional roof would be replaced. Increasing evidence suggests that green roofs may play a significant role in urban air quality improvement For example, uptake of N0x is estimated to range from $1683 to $6383 per metric ton of NOx reduction. These benefits were included in this study, and results translate to an annual benefit of $895-3392 for a 2000 square meter vegetated roof. Improved air quality leads to a mean NPV for the green roof that is 24.5-40.2% less than the mean conventional roof NPV. Through innovative policies, the inclusion of air pollution mitigation and the reduction of municipal stormwater infrastructure costs in economic valuation of environmental benefits of green roofs can reduce the cost gap that currently hinders U.S. investment in green roof technology.

  11. Hydrologic Restoration in the Urban Environment Using Green Roofs

    OpenAIRE

    Anna Palla; Ilaria Gnecco; Luca G. Lanza

    2010-01-01

    Loss of natural soil and vegetation within the urban environment can significantly affect the hydrologic cycle by increasing storm water runoff rates and volumes. In order to mitigate these modifications in urban areas engineered systems are developed, such as green roofs, to mimic and replace functions (evapo-transpiration, infiltration, percolation) which have been altered due to the impact of human development. Green roofs, also known as vegetated roof covers, eco-roofs or nature roofs, ar...

  12. Energy and Economic Evaluation of Green Roofs for Residential Buildings in Hot-Humid Climates

    Directory of Open Access Journals (Sweden)

    Abubakar S. Mahmoud

    2017-03-01

    Full Text Available Green roofs may be considered a passive energy saving technology that also offer benefits like environmental friendliness and enhancement of aesthetic and architectural qualities of buildings. This paper examines the energy and economic viability of the green roof technology in the hot humid climate of Saudi Arabia by considering a modern four bedroom residential building in the city of Dhahran as a case study. The base case and green roof modelling of the selected building has been developed with the help of DesignBuilder software. The base case model has been validated with the help of 3-month measured data about the energy consumption without a green roof installed. The result shows that the energy consumption for the base case is 169 kWh/m2 while the energy consumption due to the application of a green roof on the entire roof surface is 110 kWh/m2. For the three investigated green roof options, energy saving is found to be in the range of 24% to 35%. The economic evaluation based on the net present value (NPV approach for 40 years with consideration to other environmental advantages indicates that the benefits of the green roof technology are realized towards the end of the life cycle of the building.

  13. Evaluation of green roof characteristics in green building assessment

    Directory of Open Access Journals (Sweden)

    Sekulić Mirjana

    2013-01-01

    Full Text Available Methodology of building evaluation based on green building characteristics is rapidly gaining momentum, mainly in foreign, but also in domestic building practice. This methodology is being carried out through different Green Building Certification Systems, which are complex evaluation mechanisms based on numerous criteria of sustainability, addressing both ecological issues, but also economic and social ones. Green roof represents one of the 'must have' features of contemporary buildings aiming to gain green label. This paradigm is based on their numerous characteristics which contribute to different aspects of building sustainability, among which are savings in energy and water consumption, but also ecological balance and quality of built environment. Criteria used for evaluation of green roof solutions and their overall contribution to the building, are integral part of all of the mentioned certification systems, but the way they are structured and formulated inside each system varies significantly, hence causing differences in evaluation results. This paper presents the analysis of green roof related criteria of three characteristic green building certification systems: LEED, BREEAM and CASBEE. These systems are chosen primarily because of the different evaluation methodology, but also because of their market prevalence and perspectives of usage in the domestic practice. Conclusions driven from these analyses and comparisons provide insight into main aspect of green roof planning and construction which are relevant for the overall building sustainability assessment.

  14. The Benefits of Green Roofing for Latvian Building Environment

    OpenAIRE

    Kara, P.; Pastars, P

    2013-01-01

    Green roofs serve several purposes for a building, such as absorbing rainwater, providing insulation, creating a habitat for wildlife and helping to lower urban air temperatures and mitigate the heat island effect. The modern trend started when green roofs were developed in Germany in the 1960s, and has since spread to many countries. Today, it is estimated that about 10% of all German roofs have been “greened”. Green roofs are also becoming increasingly popular in the United States, although...

  15. Minimal watering regime impacts on desert adapted green roof plant performance

    Science.gov (United States)

    Kovachich, S.; Pavao-Zuckerman, M.; Templer, S.; Livingston, M.; Stoltz, R.; Smith, S.

    2011-12-01

    Roof tops can cover one-fifth of urban areas and can greatly alter the movement of matter and energy in cities. With traditional roofing methods and materials, roof tops readily absorb heat and as a result, buildings and the surrounding urban area heat to unnaturally high temperatures. It is hypothesized that extensive green roofs would have wide-ranging benefits for arid environments. However, little is known about the cost of water use associated with green roof installations and how to balance energy reduction needs with water costs in this water limited environment. We are conducting a pilot study to test whether a) green roofs with native plants and environmentally-responsible watering regimes will prove successful in arid environments and if b) green roofs provide ecosystem services with responsible water application. Three species of Sonoran Desert natives, Dyssodia pentachaeta (groundcover), Calliandra eriophylla (shrub), and Hesperaloe parviflora (succulent) have been planted in experimental plots [1 m2 model houses and roofs, replicated in triplicate] with two sandy, rocky desert soil mixtures (light mix: 60% expanded shale and heavy mix: organic and sandy mix with 50% shale) at the Biosphere 2 campus near Oracle, Az. The green roofs are watered by two different techniques. The first technique provides "smart watering", the minimal amount of water needed by green roof plants based on precipitation and historical data. The second watering technique is considered heavy and does not take into account environmental conditions. Preliminary data from the experimental plots shows a 30% decrease in daytime roof top temperatures on green roofs and a 10% decrease in interior temperatures in buildings with green roofs. This trend occurs with both watering regimes (heavy and light). This finding suggests that additional irrigation yields no extra heat reduction and energy savings. In order to explain this phenomenon more clearly, we use co-located temperature and

  16. Establishing green roof infrastructure through environmental policy instruments.

    Science.gov (United States)

    Carter, Timothy; Fowler, Laurie

    2008-07-01

    Traditional construction practices provide little opportunity for environmental remediation to occur in urban areas. As concerns for environmental improvement in urban areas become more prevalent, innovative practices which create ecosystem services and ecologically functional land cover in cities will be in higher demand. Green roofs are a prime example of one of these practices. The past decade has seen the North American green roof industry rapidly expand through international green roof conferences, demonstration sites, case studies, and scientific research. This study evaluates existing international and North American green roof policies at the federal, municipal, and community levels. Green roof policies fall into a number of general categories, including direct and indirect regulation, direct and indirect financial incentives, and funding of demonstration or research projects. Advantages and disadvantages of each category are discussed. Salient features and a list of prompting standards common to successfully implemented green roof strategies are then distilled from these existing policies. By combining these features with data collected from an experimental green roof site in Athens, Georgia, the planning and regulatory framework for widespread green roof infrastructure can be developed. The authors propose policy instruments be multi-faceted and spatially focused, and also propose the following recommendations: (1) Identification of green roof overlay zones with specifications for green roofs built in these zones. This spatial analysis is important for prioritizing areas of the jurisdiction where green roofs will most efficiently function; (2) Offer financial incentives in the form of density credits and stormwater utility fee credits to help overcome the barriers to entry of the new technology; (3) Construct demonstration projects and institutionalize a commitment greening roofs on publicly-owned buildings as an effective way of establishing an educated

  17. Establishing Green Roof Infrastructure Through Environmental Policy Instruments

    Science.gov (United States)

    Carter, Timothy; Fowler, Laurie

    2008-07-01

    Traditional construction practices provide little opportunity for environmental remediation to occur in urban areas. As concerns for environmental improvement in urban areas become more prevalent, innovative practices which create ecosystem services and ecologically functional land cover in cities will be in higher demand. Green roofs are a prime example of one of these practices. The past decade has seen the North American green roof industry rapidly expand through international green roof conferences, demonstration sites, case studies, and scientific research. This study evaluates existing international and North American green roof policies at the federal, municipal, and community levels. Green roof policies fall into a number of general categories, including direct and indirect regulation, direct and indirect financial incentives, and funding of demonstration or research projects. Advantages and disadvantages of each category are discussed. Salient features and a list of prompting standards common to successfully implemented green roof strategies are then distilled from these existing policies. By combining these features with data collected from an experimental green roof site in Athens, Georgia, the planning and regulatory framework for widespread green roof infrastructure can be developed. The authors propose policy instruments be multi-faceted and spatially focused, and also propose the following recommendations: (1) Identification of green roof overlay zones with specifications for green roofs built in these zones. This spatial analysis is important for prioritizing areas of the jurisdiction where green roofs will most efficiently function; (2) Offer financial incentives in the form of density credits and stormwater utility fee credits to help overcome the barriers to entry of the new technology; (3) Construct demonstration projects and institutionalize a commitment greening roofs on publicly-owned buildings as an effective way of establishing an educated

  18. Green roof establishment in extreme conditions : two case studies

    Energy Technology Data Exchange (ETDEWEB)

    Grothe, R. [Aloha Landscaping, Inc., Mendota Heights, MN (United States); Trichie, J. [Shakopee Mdewakanton Sioux Community, MN (United States)

    2007-07-01

    Green roof construction in the United States is growing at a rate of 60 to 80 per cent per year. This paper presented two case studies of green roof construction in Minnesota. In both cases, construction and budgeting delays moved the installation of the green roofs from early-May to mid-July. The first case study was a 20,000 square foot extensive green roof on the new Minneapolis Central Library which was completed in 2005. The second case study was a 30,000 square foot extensive green roof on the Mdewakanton Sioux Waste Water Treatment Plant in Shakopee, which was completed in 2006. This paper demonstrated that in order for green roofs to serve the functions for which they were intended, clear guidelines and specifications are needed to ensure that they are healthy. The size and locations of the two roofs were quite different, but they were identical in terms of waterproofing. State-of-the-art inverted hot-applied roof membrane technology was used in both roofs along with sub-surface irrigation systems. A mycorrhizae fungi was used in both cases to amend the growing medium. Both roofs used a diverse pallet of native and traditional sedum plant material. This paper highlighted preventative measures taken to ensure the successful installation and establishment of the two roofs built during extreme heat and drought-like conditions. The positive results confirm that it is possible to install green roofs during extremely harsh summer conditions. 9 refs., 4 tabs., 3 figs.

  19. Green roofs as a means of pollution abatement.

    Science.gov (United States)

    Rowe, D Bradley

    2011-01-01

    Green roofs involve growing vegetation on rooftops and are one tool that can help mitigate the negative effects of pollution. This review encompasses published research to date on how green roofs can help mitigate pollution, how green roof materials influence the magnitude of these benefits, and suggests future research directions. The discussion concentrates on how green roofs influence air pollution, carbon dioxide emissions, carbon sequestration, longevity of roofing membranes that result in fewer roofing materials in landfills, water quality of stormwater runoff, and noise pollution. Suggestions for future directions for research include plant selection, development of improved growing substrates, urban rooftop agriculture, water quality of runoff, supplemental irrigation, the use of grey water, air pollution, carbon sequestration, effects on human health, combining green roofs with complementary related technologies, and economics and policy issues.

  20. Performance Analysis of Cool Roof, Green Roof and Thermal Insulation on a Concrete Flat Roof in Tropical Climate

    OpenAIRE

    Zingre, Kishor T.; Yang, Xingguo; Wan, Man Pun

    2015-01-01

    In the tropics, the earth surface receives abundant solar radiation throughout the year contributing significantly to building heat gain and, thus, cooling demand. An effective method that can curb the heat gains through opaque roof surfaces could provide significant energy savings. This study investigates and compares the effectiveness of various passive cooling techniques including cool roof, green roof and thermal insulation for reducing the heat gain through a flat concrete roof in tropic...

  1. Creating a marketplace for green roofs in Chicago

    Energy Technology Data Exchange (ETDEWEB)

    Vitt Sale, L. [Wright and Co. Chicago, IL (United States); Berkshire, M. [City of Chicago, IL (United States)

    2004-07-01

    Since 2003, the Chicago Department of Planning and Development has been encouraging city developers to consider installing green roofs on buildings in Chicago, with the belief that this practice results in mitigation of the urban heat island effect, cleaner runoff leaving green roofs, sound attenuation, aesthetic value, oxygen production, and mitigation of carbon dioxide emissions. However, the benefits to developers, which include reduced stormwater runoff, extended roof life and energy savings, in total do not offset the first cost premium of a green roof. Despite this, and with no mandate requiring green roofs, the marketplace is growing. After seeing green roofs on a tour in Europe, the mayor of Chicago encouraged the first design and installation of a 20,300 square foot demonstration green roof in Chicago, and other city-sponsored pilot projects followed shortly after. Since then, the number of green roofs in Chicago has grown to over one million square feet. A map of Chicago showing locations of most of the projects was presented. It was suggested that lower prices for green roofs, higher energy costs and an inclination to invest in long-term strategies would accelerate the market. In an effort to engage the public in dialogue, the Department of Planning and Development held seminars to promote the benefits of green roofs . Participants had many questions about the applicability of green roofs to Chicago, expressing skepticism that Chicago's climate would provide the same benefits as in Europe. Other concerns were expressed regarding the devaluation of property values resulting from placing green roofs on buildings; doubts about roof leaks; maintenance practices; and, bugs and mold. Since the first cost premium of the system remains a question, most participants expressed interest in some kind of incentive program, but remained open-minded if benefits could be proved. 6 figs.

  2. Reviewing Green roof design approaches: Case study of residential buildings

    OpenAIRE

    Özarısoy, Bertuğ

    2013-01-01

    ABSTRACT: High density of the residential areas and steep land value in the cities have driven people to maximize liveable and productive spaces in urban settings. This includes the reinvention of roof functions extending merely as a protection from the elements to a platform of housing green building technologies such as green roofs. Increased interest in green roofs have led to advances in technology. An entire industry has sprung up which specializes in lightweight growing materials, ro...

  3. Green roof stormwater retention: effects of roof surface, slope, and media depth.

    Science.gov (United States)

    VanWoert, Nicholaus D; Rowe, D Bradley; Andresen, Jeffrey A; Rugh, Clayton L; Fernandez, R Thomas; Xiao, Lan

    2005-01-01

    Urban areas generate considerably more stormwater runoff than natural areas of the same size due to a greater percentage of impervious surfaces that impede water infiltration. Roof surfaces account for a large portion of this impervious cover. Establishing vegetation on rooftops, known as green roofs, is one method of recovering lost green space that can aid in mitigating stormwater runoff. Two studies were performed using several roof platforms to quantify the effects of various treatments on stormwater retention. The first study used three different roof surface treatments to quantify differences in stormwater retention of a standard commercial roof with gravel ballast, an extensive green roof system without vegetation, and a typical extensive green roof with vegetation. Overall, mean percent rainfall retention ranged from 48.7% (gravel) to 82.8% (vegetated). The second study tested the influence of roof slope (2 and 6.5%) and green roof media depth (2.5, 4.0, and 6.0 cm) on stormwater retention. For all combined rain events, platforms at 2% slope with a 4-cm media depth had the greatest mean retention, 87%, although the difference from the other treatments was minimal. The combination of reduced slope and deeper media clearly reduced the total quantity of runoff. For both studies, vegetated green roof systems not only reduced the amount of stormwater runoff, they also extended its duration over a period of time beyond the actual rain event.

  4. Can green roofs provide habitat for urban bees (Hymenoptera: Apidae?

    Directory of Open Access Journals (Sweden)

    Laurence Packer

    2009-01-01

    Full Text Available Increasing urbanization of many regions of the world has resulted in the decline of suitable habitat for wild flora and fauna. Green roofs have been suggested as a potential avenue to provide patches of good-quality habitat in highly developed regions. In this study, we surveyed green roofs for bee diversity and abundance to determine their potential as quality habitats in an urban area for these important pollinators. By comparing various biodiversity measures between green roofs and ground-level sites, we show that green roofs provide habitat to many bee species. Implications for pollinator conservation and urban agricultural production are discussed.

  5. NC green roof stormwater quantity and quality field evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Moran, A.; Hunt, B.; Jennings, G. [North Carolina State Univ., Raleigh, NC (United States). Dept. of Biological and Agricultural Engineering

    2004-07-01

    A study was conducted in an effort to establish design standards for green roofs in North Carolina (NC). It was conducted in light of recent regulations that require stormwater runoff to be treated by structural controls in urban development. Two extensive green roofs were constructed within the Neuse River Basin in order to estimate the per cent of precipitation retained by the green roof; estimate the per cent peak flow reduction; determine whether green roofs can be used as nutrient reduction best management practices (BMPs) and if so, what removal efficiency should be assigned to green roofs; identify green roof vegetation types that thrive in central and eastern NC and find an optimal depth of soil for desirable plant growth. The determining factors for greater water retention were found to be soil depth and plant selection. BMPs such as bioretention areas, wet and dry detention ponds, constructed wetlands, and sand filters are commonly seen throughout NC. A new option for BMPs is the green roof to use thousands of square feet available on rooftops that would not otherwise be available on the ground. Each green roof in this study retained about 60 per cent of the total recorded rainfall during a nine-month observation period. The average peak flow reduction for both green roofs was about 85 per cent. Water quality data indicated that higher concentrations of total nitrogen and total phosphorous were present in the green roof runoff than in the control roof runoff and in the rainfall at each green roof site. This may be a result of N and P leaching from the soil media, which was composed of 15 per cent compost. It was suggested that leaching could be reduced with less organic matter present in the soil media. 12 refs., 1 tab., 8 figs.

  6. Storm Water Retention on Three Green Roofs with Distinct Climates

    Science.gov (United States)

    Breach, P. A.; Sims, A.; O'Carroll, D. M.; Robinson, C. E.; Smart, C. C.; Powers, B. S. C.

    2014-12-01

    As urbanization continues to increase the impact of cities on their surrounding environments, the feasibility of implementing low-impact development such as green roofs is of increasing interest. Green roofs retain and attenuate storm water thereby reducing the load on urban sewer systems. In addition, green roofs can provide insulation and lower roof surface temperature leading to a decrease in building energy load. Green roof technology in North American urban environments remains underused, in part due to a lack of climate appropriate green roof design guidelines. The capacity of a green roof to moderate runoff depends on the storage capacity of the growing medium at the start of a rainfall event. Storage capacity is finite, which makes rapid drainage and evapotranspiration loss critical for maximizing storage capacity between subsequent storms. Here the retention and attenuation of storm events are quantified for experimental green roof sites located in three representative Canadian climates corresponding to; semiarid conditions in Calgary, Alberta, moderate conditions in London, Ontario, and cool and humid conditions in Halifax, Nova Scotia. The storage recovery and storm water retention at each site is modelled using a modified water balance approach. Components of the water balance including evapotranspiration are predicted using climate data collected from 2012 to 2014 at each of the experimental sites. During the measurement period there were over 300 precipitation events ranging from small, frequent events (green roofs in their respective climates.

  7. Green roofs in Germany : yesterday, today and tomorrow

    Energy Technology Data Exchange (ETDEWEB)

    Herman, R. [Anhalt Univ., Bernburg (Germany)

    2003-07-01

    This presentation provided a historical overview of the development of green roofs in Germany. Real interest in green roof technology in Germany began in the 1970s at which time specific guidelines for correct installation were established. In the past 20 years there has been a dramatic increase in the number of green roofs. The main market drivers were ecological concerns, energy and cost saving potential, as well as the need to manage storm water. Green roofs have an insulating effect, leading to energy savings. Some cities in Germany have implemented an incentive program whereby reductions on city water fees are allocated to owners of green roofs. Many business opportunities have been created by an increased interest in green roofs. The demand for lava, pumice, expanded clay, recycled roof tiles, crushed brick and other materials is being met by a new industry. There has been a noted increase in green roof systems and components, as well as installation and maintenance companies. It is expected that the ever increasing price for land in German cities along with an increasing population density will spur an even greater demand for green roofs. Germany is considered one of the greenest countries in the world, due to public concern for all forms of pollution, the maintenance of ecological balance, the preservation of flora and fauna, and a respect for nature. 6 refs.

  8. Evaluation on Thermal Behavior of a Green Roof Retrofit System Installed on Experimental Building in Composite Climate of Roorkee, India

    Science.gov (United States)

    Kumar, Ashok; Deoliya, Rajesh; Chani, P. S.

    2015-12-01

    Green roofs not only provide cooling by shading, but also by transpiration of water through the stomata. However, the evidence for green roofs providing significant air cooling remains limited. No literature investigates the thermal performance of prefab brick panel roofing technology with green roof. Hence, the aim of this research is to investigate the thermal behavior of an experimental room, built at CSIR-Central Building Research Institute (CBRI) campus, Roorkee, India using such roofing technology during May 2013. The study also explores the feasibility of green roof with grass carpets that require minimum irrigation, to assess the expected indoor thermal comfort improvements by doing real-time experimental studies. The results show that the proposed green roof system is suitable for reducing the energy demand for space cooling during hot summer, without worsening the winter energy performance. The cost of proposed retrofit system is about Rs. 1075 per m2. Therefore, green roofs can be used efficiently in retrofitting existing buildings in India to improve the micro-climate on building roofs and roof insulation, where the additional load carrying capacity of buildings is about 100-130 kg/m2.

  9. Green Roofs: A Part of Green Infrastructure Strategy for Urban Areas

    Science.gov (United States)

    This is a presentation on the basics of green roof technology. The presentation highlights some of the recent ORD research projects on green roofs and provides insight for the end user as to the benefits for green roof technology. It provides links to currently available EPA rep...

  10. Comparing wildlife habitat and biodiversity across green roof type

    Energy Technology Data Exchange (ETDEWEB)

    Coffman, R.R. [Oklahoma Univ., Tulsa, OK (United States). Dept. of Landscape Architecture

    2007-07-01

    Green roofs represent restorative practices within human dominated ecosystems. They create habitat, increase local biodiversity, and restore ecosystem function. Cities are now promoting this technology as a part of mitigation for the loss of local habitat, making the green roof necessary in sustainable development. While most green roofs create some form of habitat for local and migratory fauna, some systems are designed to provide specific habitat for species of concern. Despite this, little is actually known about the wildlife communities inhabiting green roofs. Only a few studies have provided broad taxa descriptions across a range of green roof habitats, and none have attempted to measure the biodiversity across green roof class. Therefore, this study examined two different vegetated roof systems representative of North America. They were constructed under alternative priorities such as energy, stormwater and aesthetics. The wildlife community appears to be a result of the green roof's physical composition. Wildlife community composition and biodiversity is expected be different yet comparable between the two general types of green roofs, known as extensive and intensive. This study recorded the community composition found in the two classes of ecoroofs and assessed biodiversity and similarity at the community and group taxa levels of insects, spiders and birds. Renyi family of diversity indices were used to compare the communities. They were further described through indices and ratios such as Shannon's, Simpson's, Sorenson and Morsita's. In general, community biodiversity was found to be slightly higher in the intensive green roof than the extensive green roof. 26 refs., 4 tabs., 4 figs.

  11. Modeling a Hydrologically Optimal Green Roof Media Mixture

    Science.gov (United States)

    Background/Questions/MethodsA key environmental concern in managing urban ecosystems is controlling stormwater runoff to ameliorate pollution problems and sewage overflows. Vegetated green roofs have become an important green infrastructure tool to collect, store, and gradually r...

  12. Extensive Green Roof Research Program at Colorado State University

    Science.gov (United States)

    In the high elevation, semi-arid climate of Colorado, green roofs have not been scientifically tested. This research examined alternative plant species, media blends, and plant interactions on an existing modular extensive green roof in Denver, Colorado. Six plant species were ev...

  13. Opportunities Green Roofs Can Offer Ghanaians and their Cities

    African Journals Online (AJOL)

    Lone Star College System

    2015-08-17

    Aug 17, 2015 ... Review. Green roofs: A possible best management practice for enhancing the ... development in Ghana in this era of climate change and variability. Key words: Green roof, .... mitigation of urban heat island effect and indoor energy consumption. ..... through buildings, air pollution, emission of greenhouse.

  14. Green roof systems: a study of public attitudes and preferences in southern Spain.

    Science.gov (United States)

    Fernandez-Cañero, Rafael; Emilsson, Tobias; Fernandez-Barba, Carolina; Herrera Machuca, Miguel Ángel

    2013-10-15

    This study investigates people's preconceptions of green roofs and their visual preference for different green roof design alternatives in relation to behavioral, social and demographical variables. The investigation was performed as a visual preference study using digital images created to represent eight different alternatives: gravel roof, extensive green roof with Sedums not in flower, extensive green roof with sedums in bloom, semi-intensive green roof with sedums and ornamental grasses, semi-intensive green roof with shrubs, intensive green roof planted with a lawn, intensive green roof with succulent and trees and intensive green roof with shrubs and trees. Using a Likert-type scale, 450 respondents were asked to indicate their preference for each digital image. Results indicated that respondents' sociodemographic characteristics and childhood environmental background influenced their preferences toward different green roof types. Results also showed that green roofs with a more careful design, greater variety of vegetation structure, and more variety of colors were preferred over alternatives.

  15. A pilot study to evaluate runoff quantity from green roofs.

    Science.gov (United States)

    Lee, Ju Young; Lee, Min Jung; Han, Mooyoung

    2015-04-01

    The use of green roofs is gaining increased recognition in many countries as a solution that can be used to improve environmental quality and reduce runoff quantity. To achieve these goals, pilot-scale green roof assemblies have been constructed and operated in an urban setting. From a stormwater management perspective, green roofs are 42.8-60.8% effective in reducing runoff for 200 mm soil depth and 13.8-34.4% effective in reducing runoff for 150 mm soil depth. By using Spearman rank correlation analysis, high rainfall intensity was shown to have a negative relationship with delayed occurrence time, demonstrating that the soil media in green roofs do not efficiently retain rainwater. Increasing the number of antecedent dry days can help to improve water retention capacity and delay occurrence time. From the viewpoint of runoff water quality, green roofs are regarded as the best management practice by filtration and adsorption through growth media (soil).

  16. Green Roof Technology- Mitigate Urban Heat Island (UHI Effect

    Directory of Open Access Journals (Sweden)

    Odli Z.S. M.

    2016-01-01

    Full Text Available Alterations on the land surfaces, which are attributed by human activities, especially in cities, cause many implications to the ecosystem. The increase of buildings in cities is reflecting the growth of human activities resulted in a significant temperature increase and warmer pattern in the urban area than the surrounding countryside. The phenomenon defined as urban heat island. This study investigates the application and efficiency of the green roof as an approach to mitigate urban heat island and reducing indoor temperature in a building. Two types of roof models, which consist of vegetative roof and non-vegetative roof, were built to investigate the efficiency of vegetated roof in reducing indoor temperature compared to the non-vegetated roof. The outdoor and indoor temperature and humidity of each roof model were monitored by using RH520 Thermo Hygrometer. The data was collected for three times in a week for 9 weeks at 9:00am to 5:00pm. It was found that the indoor average temperature data for vegetative roof could be reduced 2.4°C from the outdoor average temperature and 0.8°C for non-vegetative roof. The difference of temperature reduction for vegetative roof was greater than the nonvegetative roof, thus indicate that green roof was highly efficient in reducing indoor temperature and mitigate urban heat island impact.

  17. Green roof hydrologic performance and modeling: a review.

    Science.gov (United States)

    Li, Yanling; Babcock, Roger W

    2014-01-01

    Green roofs reduce runoff from impervious surfaces in urban development. This paper reviews the technical literature on green roof hydrology. Laboratory experiments and field measurements have shown that green roofs can reduce stormwater runoff volume by 30 to 86%, reduce peak flow rate by 22 to 93% and delay the peak flow by 0 to 30 min and thereby decrease pollution, flooding and erosion during precipitation events. However, the effectiveness can vary substantially due to design characteristics making performance predictions difficult. Evaluation of the most recently published study findings indicates that the major factors affecting green roof hydrology are precipitation volume, precipitation dynamics, antecedent conditions, growth medium, plant species, and roof slope. This paper also evaluates the computer models commonly used to simulate hydrologic processes for green roofs, including stormwater management model, soil water atmosphere and plant, SWMS-2D, HYDRUS, and other models that are shown to be effective for predicting precipitation response and economic benefits. The review findings indicate that green roofs are effective for reduction of runoff volume and peak flow, and delay of peak flow, however, no tool or model is available to predict expected performance for any given anticipated system based on design parameters that directly affect green roof hydrology.

  18. Greenbacks from green roofs: forging a new industry in Canada

    Energy Technology Data Exchange (ETDEWEB)

    Peck, S. W.; Callaghan, C. [Peck and Associates, Toronto, ON (Canada); Bass, B. [Environment Canada, Toronto, ON (Canada); Kuhn, M. [Toronto, ON (Canada)

    1999-03-01

    This report provides a comprehensive review of the qualitative and quantitative benefits of green roof and vertical garden technologies, explains the nature of roof greening and green roof systems, examines the barriers to their more rapid diffusion into Canadian markets, and makes recommendations as to how how these barriers may be overcome. Two basic types of green roof systems, extensive and intensive, are identified. Extensive green roofs are characterized by their low weight, low capital cost and low maintenance. Intensive green roofs, by contrast, are heavier, more costly to establish, require intensive planting and higher maintenance. Both types of green roofs may be further subdivided into accessible or inaccessible. Accessible green roofs are flat, outdoor open spaces intended for use as gardens or terraces, while inaccessible roofs are only accessible for periodic maintenance. 'Vertical gardens' are a type of extensive green roof, characterized by the growing of plants on or up against the facade of buildings. The many benefits of green roof or vertical garden technologies include energy cost savings due to increased insulation and improved protection of the roof membrane, air quality improvements, new employment opportunities for a wide range of people including suppliers of roof membranes and related products, and social benefits such as improved aesthetics, health and horticultural therapy. Barriers to diffusion in Canada have been identified as lack of awareness, lack of incentives to implement, cost implications, lack of technical standards, few existing examples and risks associated with uncertainty. The recommendations to overcome market barriers are intended to address these barriers, i.e. they call for increased efforts to generate awareness through addressing the knowledge availability issue, and through high profile demonstration projects, government-sponsored technology diffusion, financial incentives to overcome cost-based barriers

  19. Thermal Behavior of Green Roofs Applied to Tropical Climate

    Directory of Open Access Journals (Sweden)

    Grace Tibério Cardoso

    2013-01-01

    Full Text Available The main goal of this paper is to present results on an experimental field about the green roofs thermal behavior, compared to other traditional roof covering systems. On the one hand, it intends to describe shortly the constructive system of a green roof with a lightweight building system, which has a sustainable building materials character and, on the other, it worries with the water reuse and with the run-off delay. The main methodological procedure adopted to study the thermal behavior of green roof was installing thermocouples to collect surface temperatures and indoor air, later comparing them with existing prototypes in an experimental plot. The thermal behavior analysis of cover systems was assessed by a representative episode of the climate fact, based on the dynamic climate approach. The experimental results from internal air temperature measurements show that the green roofs applied to warm and dry climates also provide an interesting time lag with surface and internal air temperature reduction.

  20. Experimental analysis of green roof substrate detention characteristics.

    Science.gov (United States)

    Yio, Marcus H N; Stovin, Virginia; Werdin, Jörg; Vesuviano, Gianni

    2013-01-01

    Green roofs may make an important contribution to urban stormwater management. Rainfall-runoff models are required to evaluate green roof responses to specific rainfall inputs. The roof's hydrological response is a function of its configuration, with the substrate - or growing media - providing both retention and detention of rainfall. The objective of the research described here is to quantify the detention effects due to green roof substrates, and to propose a suitable hydrological modelling approach. Laboratory results from experimental detention tests on green roof substrates are presented. It is shown that detention increases with substrate depth and as a result of increasing substrate organic content. Model structures based on reservoir routing are evaluated, and it is found that a one-parameter reservoir routing model coupled with a parameter that describes the delay to start of runoff best fits the observed data. Preliminary findings support the hypothesis that the reservoir routing parameter values can be defined from the substrate's physical characteristics.

  1. Modelling of green roof hydrological performance for urban drainage applications

    DEFF Research Database (Denmark)

    Locatelli, Luca; Mark, Ole; Mikkelsen, Peter Steen

    2014-01-01

    Green roofs are being widely implemented for stormwater management and their impact on the urban hydrological cycle can be evaluated by incorporating them into urban drainage models. This paper presents a model of green roof long term and single event hydrological performance. The model includes...... from 3 different extensive sedum roofs in Denmark. These data consist of high-resolution measurements of runoff, precipitation and atmospheric variables in the period 2010–2012. The hydrological response of green roofs was quantified based on statistical analysis of the results of a 22-year (1989...... and that the mean annual runoff is not linearly related to the storage. Green roofs have therefore the potential to be important parts of future urban stormwater management plans....

  2. MODELING OF STORM WATER RUNOFF FROM GREEN ROOFS

    OpenAIRE

    Ewa Burszta-Adamiak; Wiesław Fiałkiewicz

    2014-01-01

    Apart from direct measurements, modelling of runoff from green roofs is valuable source of information about effectiveness of this type of structure from hydrological point of view. Among different type of models, the most frequently used are numerical models. They allow to assess the impact of green roofs on decrease and attenuation of runoff, reduction of peak runoff and value of water retention. This paper presents preliminary results of research on computing the rate of runoff from green ...

  3. Hydrologic Restoration in the Urban Environment Using Green Roofs

    Directory of Open Access Journals (Sweden)

    Anna Palla

    2010-04-01

    Full Text Available Loss of natural soil and vegetation within the urban environment can significantly affect the hydrologic cycle by increasing storm water runoff rates and volumes. In order to mitigate these modifications in urban areas engineered systems are developed, such as green roofs, to mimic and replace functions (evapo-transpiration, infiltration, percolation which have been altered due to the impact of human development. Green roofs, also known as vegetated roof covers, eco-roofs or nature roofs, are composite complex layered structures with specific environmental benefits. They are increasingly being used as a source control measure for urban storm water management. Indeed, they are able to re-establish the natural water cycle processes and to operate hydrologic control over storm water runoff with a derived peak flow attenuation, runoff volume reduction and increase of the time of concentration. Furthermore green roofs exhibit the capacity to reduce storm water pollution; they generally act as a storage device, consequently pollutants are accumulated in the substrate layer and released when intensive rainwater washes them out. In order to investigate the hydrologic response of a green roof, the University of Genova recently developed a joint laboratory and full-scale monitoring programme by installing a “controlled” laboratory test-bed with known rainfall input and a companion green roof experimental site (40 cm depth in the town of Genoa. In the paper, data collected during the monitoring programme are presented and compared with literature data.

  4. Estimating Heat and Mass Transfer Processes in Green Roof Systems: Current Modeling Capabilities and Limitations (Presentation)

    Energy Technology Data Exchange (ETDEWEB)

    Tabares Velasco, P. C.

    2011-04-01

    This presentation discusses estimating heat and mass transfer processes in green roof systems: current modeling capabilities and limitations. Green roofs are 'specialized roofing systems that support vegetation growth on rooftops.'

  5. A field study to evaluate runoff quality from green roofs.

    Science.gov (United States)

    Vijayaraghavan, K; Joshi, U M; Balasubramanian, R

    2012-03-15

    Green (vegetated) roofs are emerging as practical strategies to improve the environmental quality of cities. However, the impact of green roofs on the storm water quality remains a topic of concern to city planners and environmental policy makers. This study investigated whether green roofs act as a source or a sink of various metals (Na, K, Ca, Mg, Al, Fe, Cu, Cd, Pb, Zn, Mn, Cr, Ni, Li and Co), inorganic anions (NO3-, NO2-, PO4(3-), SO4(2-), Cl-, F- and Br-) and cation (NH4+). A series of green roof assemblies were constructed. Four different real rain events and several artificial rain events were considered for the study. Results showed that concentrations of most of the chemical components in runoff were highest during the beginning of rain events and subsided in the subsequent rain events. Some of the important components present in the runoff include Na, K, Ca, Mg, Li, Fe, Al, Cu, NO3-, PO4(3-) and SO4(2-). However, the concentration of these chemical components in the roof runoff strongly depends on the nature of substrates used in the green roof and the volume of rain. Based on the USEPA standards for freshwater quality, we conclude that the green roof used in this study is reasonably effective except that the runoff contains significant amounts of NO3- and PO4(3-).

  6. Reliability Analysis of a Green Roof Under Different Storm Scenarios

    Science.gov (United States)

    William, R. K.; Stillwell, A. S.

    2015-12-01

    Urban environments continue to face the challenges of localized flooding and decreased water quality brought on by the increasing amount of impervious area in the built environment. Green infrastructure provides an alternative to conventional storm sewer design by using natural processes to filter and store stormwater at its source. However, there are currently few consistent standards available in North America to ensure that installed green infrastructure is performing as expected. This analysis offers a method for characterizing green roof failure using a visual aid commonly used in earthquake engineering: fragility curves. We adapted the concept of the fragility curve based on the efficiency in runoff reduction provided by a green roof compared to a conventional roof under different storm scenarios. We then used the 2D distributed surface water-groundwater coupled model MIKE SHE to model the impact that a real green roof might have on runoff in different storm events. We then employed a multiple regression analysis to generate an algebraic demand model that was input into the Matlab-based reliability analysis model FERUM, which was then used to calculate the probability of failure. The use of reliability analysis as a part of green infrastructure design code can provide insights into green roof weaknesses and areas for improvement. It also supports the design of code that is more resilient than current standards and is easily testable for failure. Finally, the understanding of reliability of a single green roof module under different scenarios can support holistic testing of system reliability.

  7. Can green roof act as a sink for contaminants? A methodological study to evaluate runoff quality from green roofs.

    Science.gov (United States)

    Vijayaraghavan, K; Joshi, Umid Man

    2014-11-01

    The present study examines whether green roofs act as a sink or source of contaminants based on various physico-chemical parameters (pH, conductivity and total dissolved solids) and metals (Na, K, Ca, Mg, Al, Fe, Cr, Cu, Ni, Zn, Cd and Pb). The performance of green roof substrate prepared using perlite, vermiculite, sand, crushed brick, and coco-peat, was compared with local garden soil based on improvement of runoff quality. Portulaca grandiflora was used as green roof vegetation. Four different green roof configurations, with vegetated and non-vegetated systems, were examined for several artificial rain events (un-spiked and metal-spiked). In general, the vegetated green roof assemblies generated better-quality runoff with less conductivity and total metal ion concentration compared to un-vegetated assemblies. Of the different green roof configurations examined, P. grandiflora planted on green roof substrate acted as sink for various metals and showed the potential to generate better runoff.

  8. Ecological Impacts of Replacing Traditional Roofs with Green Roofs in Two Urban Areas

    Directory of Open Access Journals (Sweden)

    Timothy Carter

    2008-01-01

    Full Text Available Urban land cover is dominated by impervious surface that degrades both terrestrial and aquatic ecosystems relative to predevelopment conditions. There are significant opportunities for designers of urban landscapes to use alternative land covers that have multiple functions, benefiting both human and nonhuman components of the urban ecosystem. Vegetated (green roofs are one form of alternative land cover that has shown the potential to provide a variety of ecological benefits in urban areas. We evaluated how stormwater retention, building energy and temperature, and rooftop habitat are influenced by the use of green roofs using test plots in Georgia and Massachusetts. Green roofs were shown to recreate part of the predevelopment hydrology through increasing interception, stormwater storage, evaporation, and transpiration on the rooftop and worked extremely well for small storm events. Temperature reductions were found on the green rooftop as compared to an asphalt surface, although other roof technologies that minimize temperatures, such as lighter colored membranes, provide similar benefits. Novel habitat was created on the rooftop, although the extent of this habitat was limited in part by plant survivability and the need for additional water inputs for diverse plant communities to survive. Despite the challenges, the green roof benefits reported here suggest that green roofs can be used effectively as a multifunctional land cover in urban areas.

  9. Stormwater quality from extensive green roofs in a subtropical region

    Science.gov (United States)

    Onis Pessoa, Jonas; Allasia, Daniel; Tassi, Rutineia; Vaz Viega, Juliana; Fensterseifer, Paula

    2016-04-01

    Green roofs have increasingly become an integral part of urban environments, mainly due to their aesthetic benefits, thermal comfort and efficiency in controlling excess runoff. However, the effects of this emerging technology in the qualitative characteristics of rainwater is still poorly understood. In this study was evaluated the effect of two different extensive green roofs (EGRs) and a traditional roof built with corrugated fiber cement sheets (control roof) in the quality of rainwater, in a subtropical climate area in the city of Santa Maria, in southern Brazil. The principal variant between the two EGRs were the type of plant species, time since construction, soil depth and the substrate characteristics. During the monitoring period of the experiment, between the months of April and December of 2015 fourteen rainfall events were selected for qualitative analysis of water from the three roofs and directly from rainfall. It was analyzed physical (turbidity, apparent color, true color, electrical conductivity, total solids, dissolved solids, suspended solids and temperature), chemical (pH, phosphate, total nitrogen, nitrate, nitrite, chloride, sulfate, BOD, iron and total hardness), heavy metals (copper, zinc, lead and chromium) and microbiological parameters (total coliforms and E. coli). It was also characterized the substrates used in both extensive green roofs. The results showed that the quality of the water drained from EGR s was directly influenced by their substrates (in turn containing significant levels of nutrients, organic matter and some metals). The passage of rainwater through green roofs and control roof resulted in the elevation of pH, allowing the conversion of the slightly acidic rainfall into basic water. Similarly, on both types of roofs occurred an increase of the values of most of the physical, chemical and microbiological parameters compared to rainwater. This same trend was observed for heavy metals, although with a much smaller degree

  10. Experimental measurements and numerical modelling of a green roof

    Energy Technology Data Exchange (ETDEWEB)

    Lazzarin, Renato M.; Castellotti, Francesco; Busato, Filippo [Padova Univ., Dept. of Management and Engineering, Vicenza (Italy)

    2005-12-15

    Green roof utilisation has been known since ancient times both in hot and cold climates. Nowadays, it has been reconsidered at issue of energy saving and pollution reduction. In this paper, some measurement sessions on a green roof installed by the Vicenza Hospital are described. A data logging system with temperature, humidity, rainfall, radiation, etc. sensors surveyed both the parameters related to the green roof and to the rooms underneath. The aim is to evaluate the passive cooling, stressing the evapotranspiration role in summer time. Furthermore, the enhanced insulating properties have been tested during winter time. A predictive numerical model has been developed in a building simulation software (TRNSYS) to calculate thermal and energy performances of a building with a green roof, varying the meteorological dataset for a specific geographic zone. (Author)

  11. MODELING OF STORM WATER RUNOFF FROM GREEN ROOFS

    Directory of Open Access Journals (Sweden)

    Ewa Burszta-Adamiak

    2014-10-01

    Full Text Available Apart from direct measurements, modelling of runoff from green roofs is valuable source of information about effectiveness of this type of structure from hydrological point of view. Among different type of models, the most frequently used are numerical models. They allow to assess the impact of green roofs on decrease and attenuation of runoff, reduction of peak runoff and value of water retention. This paper presents preliminary results of research on computing the rate of runoff from green roofs using GARDENIA model. The analysis has been carried out for selected rainfall events registered during measuring campaign on pilot-scale green roofs. Obtained results are promising and show good fit between observed and simulated runoff.

  12. Soil-water fluxes modelling in a green roof

    Science.gov (United States)

    Lamera, Carlotta; Rulli, Maria Cristina; Becciu, Gianfranco; Rosso, Renzo

    2014-05-01

    Green roofs differ from a natural environment as they are on top of a building and are not connected to the natural ground; therefore it is critical that soils can drain and retain water simultaneously and that they work even in very shallow systems. The soil or growing medium used for green roofs is specifically engineered to provide the vegetation with nutrients, discharging any excess water into the drainage layer, and releasing stored water back into the substrate. In this way, medium depth and porosity plays an important role in stormwater retention and plant growth in a green roof. Due to the lack of a good understanding about the hydraulic efficiency of each green roof's layer in rainwater management, a detailed analysis of the hydrological dynamics, connected with the green roof technical design is essential in order to obtain a full characterization of the hydrologic behavior of a green roof system and its effects on the urban water cycle components. The purpose of this research is analyzing the soil-water dynamics through the different components of a green roof and modeling these processes though a detailed but clear subsurface hydrology module, based on green roof vertical soil water movement reproduction, in relation to climate forcing, basic technology components and geometric characteristics of green roof systems (thickness of the stratigraphy, soil layers and materials, vegetation typology and density). A multi-layer bucket model has been applied to examine the hydrological response of the green roof system under a temperate maritime climate, by varying the physical and geometric parameters that characterize the different components of the vegetated cover. Following a stage of validation and calibration, results confirm the suitability of the model to describe the hydrologic response of the green roof during the observed rainfall events: the discharge hydrograph profile, volume and timing, predicted by the model, matched experimental measurements

  13. Evaluation of Physically and Empirically Based Models for the Estimation of Green Roof Evapotranspiration

    Science.gov (United States)

    Digiovanni, K. A.; Montalto, F. A.; Gaffin, S.; Rosenzweig, C.

    2010-12-01

    Green roofs and other urban green spaces can provide a variety of valuable benefits including reduction of the urban heat island effect, reduction of stormwater runoff, carbon sequestration, oxygen generation, air pollution mitigation etc. As many of these benefits are directly linked to the processes of evaporation and transpiration, accurate and representative estimation of urban evapotranspiration (ET) is a necessary tool for predicting and quantifying such benefits. However, many common ET estimation procedures were developed for agricultural applications, and thus carry inherent assumptions that may only be rarely applicable to urban green spaces. Various researchers have identified the estimation of expected urban ET rates as critical, yet poorly studied components of urban green space performance prediction and cite that further evaluation is needed to reconcile differences in predictions from varying ET modeling approaches. A small scale green roof lysimeter setup situated on the green roof of the Ethical Culture Fieldston School in the Bronx, NY has been the focus of ongoing monitoring initiated in June 2009. The experimental setup includes a 0.6 m by 1.2 m Lysimeter replicating the anatomy of the 500 m2 green roof of the building, with a roof membrane, drainage layer, 10 cm media depth, and planted with a variety of Sedum species. Soil moisture sensors and qualitative runoff measurements are also recorded in the Lysimeter, while a weather station situated on the rooftop records climatologic data. Direct quantification of actual evapotranspiration (AET) from the green roof weighing lysimeter was achieved through a mass balance approaches during periods absent of precipitation and drainage. A comparison of AET to estimates of potential evapotranspiration (PET) calculated from empirically and physically based ET models was performed in order to evaluate the applicability of conventional ET equations for the estimation of ET from green roofs. Results have

  14. Rainwater runoff retention on an aged intensive green roof.

    Science.gov (United States)

    Speak, A F; Rothwell, J J; Lindley, S J; Smith, C L

    2013-09-01

    Urban areas are characterised by large proportions of impervious surfaces which increases rainwater runoff and the potential for surface water flooding. Increased precipitation is predicted under current climate change projections, which will put further pressure on urban populations and infrastructure. Roof greening can be used within flood mitigation schemes to restore the urban hydrological balance of cities. Intensive green roofs, with their deeper substrates and higher plant biomass, are able to retain greater quantities of runoff, and there is a need for more studies on this less common type of green roof which also investigate the effect of factors such as age and vegetation composition. Runoff quantities from an aged intensive green roof in Manchester, UK, were analysed for 69 rainfall events, and compared to those on an adjacent paved roof. Average retention was 65.7% on the green roof and 33.6% on the bare roof. A comprehensive soil classification revealed the substrate, a mineral soil, to be in good general condition and also high in organic matter content which can increase the water holding capacity of soils. Large variation in the retention data made the use of predictive regression models unfeasible. This variation arose from complex interactions between Antecedant Dry Weather Period (ADWP), season, monthly weather trends, and rainfall duration, quantity and peak intensity. However, significantly lower retention was seen for high rainfall events, and in autumn, which had above average rainfall. The study period only covers one unusually wet year, so a longer study may uncover relationships to factors which can be applied to intensive roofs elsewhere. Annual rainfall retention for Manchester city centre could be increased by 2.3% by a 10% increase in intensive green roof construction. The results of this study will be of particular interest to practitioners implementing greenspace adaptation in temperate and cool maritime climates.

  15. Modelling of green roofs' hydrologic performance using EPA's SWMM.

    Science.gov (United States)

    Burszta-Adamiak, E; Mrowiec, M

    2013-01-01

    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.

  16. Comparative life cycle assessment of standard and green roofs.

    Science.gov (United States)

    Saiz, Susana; Kennedy, Christopher; Bass, Brad; Pressnail, Kim

    2006-07-01

    Life cycle assessment (LCA) is used to evaluate the benefits, primarily from reduced energy consumption, resulting from the addition of a green roof to an eight story residential building in Madrid. Building energy use is simulated and a bottom-up LCA is conducted assuming a 50 year building life. The key property of a green roof is its low solar absorptance, which causes lower surface temperature, thereby reducing the heat flux through the roof. Savings in annual energy use are just over 1%, but summer cooling load is reduced by over 6% and reductions in peak hour cooling load in the upper floors reach 25%. By replacing the common flat roof with a green roof, environmental impacts are reduced by between 1.0 and 5.3%. Similar reductions might be achieved by using a white roof with additional insulation for winter, but more substantial reductions are achieved if common use of green roofs leads to reductions in the urban heat island.

  17. Plant species richness enhances nitrogen retention in green roof plots.

    Science.gov (United States)

    Johnson, Catherine; Schweinhart, Shelbye; Buffam, Ishi

    2016-10-01

    Vegetated (green) roofs have become common in many cities and are projected to continue to increase in coverage, but little is known about the ecological properties of these engineered ecosystems. In this study, we tested the biodiversity-ecosystem function hypothesis using commercially available green roof trays as replicated plots with varying levels of plant species richness (0, 1, 3, or 6 common green roof species per plot, using plants with different functional characteristics). We estimated accumulated plant biomass near the peak of the first full growing season (July 2013) and measured runoff volume after nearly every rain event from September 2012 to September 2013 (33 events) and runoff fluxes of inorganic nutrients ammonium, nitrate, and phosphate from a subset of 10 events. We found that (1) total plant biomass increased with increasing species richness, (2) green roof plots were effective at reducing storm runoff, with vegetation increasing water retention more than soil-like substrate alone, but there was no significant effect of plant species identity or richness on runoff volume, (3) green roof substrate was a significant source of phosphate, regardless of presence/absence of plants, and (4) dissolved inorganic nitrogen (DIN = nitrate + ammonium) runoff fluxes were different among plant species and decreased significantly with increasing plant species richness. The variation in N retention was positively related to variation in plant biomass. Notably, the increased biomass and N retention with species richness in this engineered ecosystem are similar to patterns observed in published studies from grasslands and other well-studied ecosystems. We suggest that more diverse plantings on vegetated roofs may enhance the retention capacity for reactive nitrogen. This is of importance for the sustained health of vegetated roof ecosystems, which over time often experience nitrogen limitation, and is also relevant for water quality in receiving waters

  18. The Feasibility of Installing and Monitoring an Extensive Green Roof at Purdue University

    OpenAIRE

    2007-01-01

    The Boiler Green Initiative (BGI) is a student-run organization working to improve environmental sustainability at the Purdue University West Lafayette campus. A main goal of BGI's is to install a green roof on an existing building on campus that is being replaced. We discuss the benefits of green roofs, the feasibility of having one installed on the Armory's roof and the various monitoring options we have researched. Flat roofs are especially amenable to the green roof system, so a building ...

  19. Developing resilient green roofs in a dry climate.

    Science.gov (United States)

    Razzaghmanesh, M; Beecham, S; Brien, C J

    2014-08-15

    Living roofs are an emerging green infrastructure technology that can potentially be used to ameliorate both climate change and urban heat island effects. There is not much information regarding the design of green roofs for dry climates and so the aim of this study was to develop low maintenance and unfertilized green roofs for a dry climate. This paper describes the effects of four important elements of green roofs namely slope, depth, growing media and plant species and their possible interactions in terms of plant growth responses in a dry climate. Sixteen medium-scale green roofs were set up and monitored during a one year period. This experiment consisted of twelve vegetated platforms and four non-vegetated platforms as controls. The design for the experiment was a split-split-plot design in which the factors Slope (1° and 25°) and Depth (100mm, 300 mm) were randomized to the platforms (main plots). Root depth and volume, average height of plants, final dry biomass and ground cover, relative growth rate, final dry shoot-root ratio, water use efficiency and leaf succulence were studied during a twelve month period. The results showed little growth of the plants in media type A, whilst the growth was significant in both media types B and C. On average, a 90% survival rate of plants was observed. Also the growth indices indicated that some plants can grow efficiently in the harsh environment created by green roofs in a dry climate. The root growth pattern showed that retained water in the drainage layer is an alternative source of water for plants. It was also shown that stormwater can be used as a source of irrigation water for green roofs during six months of the year at the study site. In summary, mild sloping intensive systems containing media type C and planted with either Chrysocephalum apiculatum or Disphyma crassifolium showed the best performance.

  20. Composition and Diversity of Avian Communities Using a New Urban Habitat: Green Roofs

    Science.gov (United States)

    Washburn, Brian E.; Swearingin, Ryan M.; Pullins, Craig K.; Rice, Matthew E.

    2016-06-01

    Green roofs on buildings are becoming popular and represent a new component of the urban landscape. Public benefits of green roof projects include reduced stormwater runoff, improved air quality, reduced urban heat island effects, and aesthetic values. As part of a city-wide plan, several green roofs have been constructed at Chicago's O'Hare International Airport (ORD). Like some other landscaping features, green roofs on or near an airport might attract wildlife and thus increase the risk of bird-aircraft collisions. During 2007-2011, we conducted a series of studies to evaluate wildlife use of newly constructed green roofs and traditional (gravel) roofs on buildings at ORD. These green roofs were 0.04-1.62 ha in area and consisted of primarily stonecrop species for vegetation. A total of 188 birds were observed using roofs during this research. Of the birds using green roofs, 66, 23, and 4 % were Killdeer, European Starlings, and Mourning Doves, respectively. Killdeer nested on green roofs, whereas the other species perched, foraged, or loafed. Birds used green roofs almost exclusively between May and October. Overall, avian use of the green roofs was minimal and similar to that of buildings with traditional roofs. Although green roofs with other vegetation types might offer forage or cover to birds and thus attract potentially hazardous wildlife, the stonecrop-vegetated green roofs in this study did not increase the risk of bird-aircraft collisions.

  1. Manipulating soil microbial communities in extensive green roof substrates.

    Science.gov (United States)

    Molineux, Chloe J; Connop, Stuart P; Gange, Alan C

    2014-09-15

    There has been very little investigation into the soil microbial community on green roofs, yet this below ground habitat is vital for ecosystem functioning. Green roofs are often harsh environments that would greatly benefit from having a healthy microbial system, allowing efficient nutrient cycling and a degree of drought tolerance in dry summer months. To test if green roof microbial communities could be manipulated, we added mycorrhizal fungi and a microbial mixture ('compost tea') to green roof rootzones, composed mainly of crushed brick or crushed concrete. The study revealed that growing media type and depth play a vital role in the microbial ecology of green roofs. There are complex relationships between depth and type of substrate and the biomass of different microbial groups, with no clear pattern being observed. Following the addition of inoculants, bacterial groups tended to increase in biomass in shallower substrates, whereas fungal biomass change was dependent on depth and type of substrate. Increased fungal biomass was found in shallow plots containing more crushed concrete and deeper plots containing more crushed brick where compost tea (a live mixture of beneficial bacteria) was added, perhaps due to the presence of helper bacteria for arbuscular mycorrhizal fungi (AMF). Often there was not an additive affect of the microbial inoculations but instead an antagonistic interaction between the added AM fungi and the compost tea. This suggests that some species of microbes may not be compatible with others, as competition for limited resources occurs within the various substrates. The overall results suggest that microbial inoculations of green roof habitats are sustainable. They need only be done once for increased biomass to be found in subsequent years, indicating that this is a novel and viable method of enhancing roof community composition.

  2. Retention performance of green roofs in three different climate regions

    Science.gov (United States)

    Sims, Andrew W.; Robinson, Clare E.; Smart, Charles C.; Voogt, James A.; Hay, Geoffrey J.; Lundholm, Jeremey T.; Powers, Brandon; O'Carroll, Denis M.

    2016-11-01

    Green roofs are becoming increasingly popular for moderating stormwater runoff in urban areas. This study investigated the impact different climates have on the retention performance of identical green roofs installed in London Ontario (humid continental), Calgary Alberta (semi-arid, continental), and Halifax Nova Scotia (humid, maritime). Drier climates were found to have greater percent cumulative stormwater retention with Calgary (67%) having significantly better percent retention than both London (48%) and Halifax (34%). However, over the same study period the green roof in London retained the greatest depth of stormwater (598 mm), followed by the green roof in Halifax (471 mm) and then Calgary (411 mm). The impact of climate was largest for medium sized storms where the antecedent moisture condition (AMC) at the beginning of a rainfall event governs retention performance. Importantly AMC was a very good predictor of stormwater retention, with similar retention at all three sites for a given AMC, emphasizing that AMC is a relevant indicator of retention performance in any climate. For large rainfall events (i.e., >45 mm) green roof average retention ranged between 16% and 29% in all cities. Overall, drier climates have superior retention due to lower AMC in the media. However, moderate and wet climates still provide substantial total volume reduction benefits.

  3. The effects of green roofs in a sub-tropical system

    Energy Technology Data Exchange (ETDEWEB)

    Simmons, M. [Austin Univ., Austin, TX (United States). Lady Bird Johnson Wildflower Center; Gardiner, B. [Austech Roof Consultants Inc., Austin, TX (United States)

    2007-07-01

    The building and environmental benefits of green roofs in non-temperate, or subtropical systems were discussed. Since there are greater climatic extremes in such systems, green roofs may offer more benefits. Most green roof research has focused on the use of succulent plants due to their low water demand and slow growth rates. The Lady Bird Johnson Wildflower Center and the Roof Consultants Institute Foundation are conducting joint research project to assess the suitability of native vegetation for use on extensive green roofs in central Texas. The project examined the effects of green roofing in a subtropical climate and the thermal properties of buildings, stormwater runoff rates, water quality, and irrigation requirements. Stormwater retention capacity of green roofs and water quality of stormwater runoff was compared to conventional roofs. The growing media that are most successful for this particular ecoregion was also identified. The focus on native plants in this study identified the characteristics of climatic adaptation, which may help to reduce total water and nutrient demand, and avoid problems associated with the introduction of potentially invasive species. The study compared performance of 6 types of green roofs and two types of traditional roof materials using simulated roof platforms. During the hottest days in August, roof membrane temperatures on the green roofs were 10 degrees C cooler than white roofs and 40 degrees C cooler than conventional black roofs. It was concluded that the temperature and water quantity characteristics of green roofs are advantageous in subtropical climates. 4 refs., 1 tab., 4 figs.

  4. Entire cities could benefit from green roofs : Heleen Mees is investigating how five metropolises are greenifying their roofs

    OpenAIRE

    Mees, Heleen

    2014-01-01

    Rotterdam is making good progress with its creation of green roofs. Heleen Mees, researcher at Utrecht University, drew this conclusion from her research, in which she compared the green roof policy of four different cities with that of Rotterdam. Rotterdam awards grants to those wishing to create a green roof, thereby helping to promote the general acceptance of green roofs in the city. However, the researcher thinks this policy should be followed up: “You can’t award grants forever.”

  5. Technical considerations in green roof retrofit for stormwater attenuation in the central business district

    OpenAIRE

    Wilkinson, S.; Lamond, J.; Proverbs, D.; Sharman, L.; Heller, A; Manion, J.

    2015-01-01

    Purpose: The key aspects that built environment professionals need to consider when evaluating roofs for the purpose of green roof retrofit and also when assessing green roofs for technical due diligence purposes are outlined. Although green or sod roofs have been built over many centuries, contemporary roofs adopt new approaches and technologies. The paper aims to discuss these issues. \\ud \\ud Design/methodology/approach: A mixed methods design based on a systematic review of relevant litera...

  6. Plant functional traits predict green roof ecosystem services.

    Science.gov (United States)

    Lundholm, Jeremy; Tran, Stephanie; Gebert, Luke

    2015-02-17

    Plants make important contributions to the services provided by engineered ecosystems such as green roofs. Ecologists use plant species traits as generic predictors of geographical distribution, interactions with other species, and ecosystem functioning, but this approach has been little used to optimize engineered ecosystems. Four plant species traits (height, individual leaf area, specific leaf area, and leaf dry matter content) were evaluated as predictors of ecosystem properties and services in a modular green roof system planted with 21 species. Six indicators of ecosystem services, incorporating thermal, hydrological, water quality, and carbon sequestration functions, were predicted by the four plant traits directly or indirectly via their effects on aggregate ecosystem properties, including canopy density and albedo. Species average height and specific leaf area were the most useful traits, predicting several services via effects on canopy density or growth rate. This study demonstrates that easily measured plant traits can be used to select species to optimize green roof performance across multiple key services.

  7. A New Kind of Roof Greening System in China

    Institute of Scientific and Technical Information of China (English)

    2015-01-01

    With the wider use of green roofs, new technology and new materials are being applied to the field of building roof greening forbuildings. This paper introduces BRGS (built- up roof greening system), a new type of roof greening system that differs from roofgreening systems currently used in China in that it integrates a main and an auxiliary water storage capacity into the roof greeningsystem. Compared to other systems currently in use, BRGS offers a simpler, quicker, less labor intensive construction process;lighter floor load; and lower long term maintenance requirements and costs. It also makes full use of rainwater and snowmelt,which provides a significant amount of water to plants. This paper also introduces a planting experiment, the results of whichindicate that plants during their early stages of growth tolerate an alkaline environment, and that after a period of time, the pHvalue level of water stored in BRGS approaches 8.3, so we can conclude that BRGS is suitable for construction engineering.

  8. Choosing the right green roof media for water quality

    Energy Technology Data Exchange (ETDEWEB)

    Hunt, W.F.; Hathaway, A.M.; Smith, J.T.; Calabria, J. [North Carolina State Univ., Raleigh, NC (United States). Dept. of Biological and Agricultural Engineering

    2006-07-01

    Due to the large concentrations of a variety of contaminants entering streams and rivers, stormwater is a significant contributor to the impairment of North Carolina (NC) waters. Pollutants range from pesticides and nutrients to oils and petroleum products to construction chemicals and sediment which are evident in fish kills, contamination of drinking water supplies, and deterioration of wildlife habitats. One of the major tools to improve storm water quality are stormwater best management practices (BMPs). BMPs include bioretention areas, wet and dry detention ponds, constructed wetlands, and sand filters. One option for urban BMPs is the green roof which uses rooftop square footage that would not otherwise be available on the ground. A research project was conducted that tests two field green roofs in Raleigh and Asheville, NC. In addition, a laboratory test was conducted in 2004 and a plot study of three designer media was conducted in 2005 on the NC State University Campus in Raleigh, NC. The objectives of the research were to examine how different green roof media reduce concentrations of nitrogen and phosphorus, if the leaching rate of nitrogen and phosphorus from soil media of field green roofs decrease with time, and to determine whether green roofs can be used as nutrient reduction BMPs. This paper provided background information on previous green roof stormwater research, discussed each of the sites chosen for the study in detail and presented the field monitoring process and laboratory study methodology. This was followed by a detailed examination of the results. It was concluded that an optimal soil media can be established that balances plant growth with water quality and quantity control. 16 refs., 2 tabs., 8 figs.

  9. Performance Evaluation and Field Application of Red Clay Green Roof Vegetation Blocks for Ecological Restoration Projects

    Directory of Open Access Journals (Sweden)

    Hwang-Hee Kim

    2017-02-01

    Full Text Available In this study, for restoration of ecological systems in buildings, porous vegetation red clay green roof blocks were designed for performance evaluation. Blast furnace slag (BFS; fine aggregates (agg., coarse aggregates, polyvinyl alcohol (PVA fiber (hydrophilic fiber, and red clay (ecofriendly additive material were applied to the construction of the porous vegetation red clay green roof blocks. A decrease in cement use is one way of reducing carbon emissions. To increase the water retentivity and the efficiency of roof vegetation blocks, blast furnace slag aggregates with excellent water absorptivity and polyvinyl alcohol fiber with a water absorption rate above 20% were added. In particular, the addition of polyvinyl alcohol fiber prevents performance reduction of the green roof vegetation blocks during freezing and melting in winter. Compressive strength, void ratio, and unit-mass tests were conducted to evaluate the performance of the roof vegetation blocks. After their application to roof vegetation, the effect of water purification was evaluated. According to the experimental results, the mix that satisfies the target performance of green roof vegetation blocks (compression strength above 8 MPa, void ratio above 20%, unit mass 2.0 kg/cm3 or below is: cement = 128.95 kg/m3, BFS = 96.75 kg/m3, red clay = 96.75 kg/m3, water = 81.50 kg/m3, BFS agg. = 1450 kg/m3, PVA fiber = 1.26 kg/m3. The green roof vegetation blocks were designed using the mix that satisfied the target performance. To find the amount of attainable water due to rainfall, a rainfall meter was installed after application of the roof vegetation to measure daily rainfall and calculate the amount of attainable water. The results show that, for 1 mm of rainfall, it is possible to attain about 0.53 L of water per 1 m2. In addition, the water quality of effluents after application of roof vegetation was analyzed, and the results satisfied Class 4 of the River-life Environmental

  10. Retention performance of green roofs in representative climates worldwide

    Science.gov (United States)

    Viola, F.; Hellies, M.; Deidda, R.

    2017-10-01

    The ongoing process of global urbanization contributes to an increase in stormwater runoff from impervious surfaces, threatening also water quality. Green roofs have been proved to be innovative stormwater management measures to partially restore natural states, enhancing interception, infiltration and evapotranspiration fluxes. The amount of water that is retained within green roofs depends not only on their depth, but also on the climate, which drives the stochastic soil moisture dynamic. In this context, a simple tool for assessing performance of green roofs worldwide in terms of retained water is still missing and highly desirable for practical assessments. The aim of this work is to explore retention performance of green roofs as a function of their depth and in different climate regimes. Two soil depths are investigated, one representing the intensive configuration and another representing the extensive one. The role of the climate in driving water retention has been represented by rainfall and potential evapotranspiration dynamics. A simple conceptual weather generator has been implemented and used for stochastic simulation of daily rainfall and potential evapotranspiration. Stochastic forcing is used as an input of a simple conceptual hydrological model for estimating long-term water partitioning between rainfall, runoff and actual evapotranspiration. Coupling the stochastic weather generator with the conceptual hydrological model, we assessed the amount of rainfall diverted into evapotranspiration for different combinations of annual rainfall and potential evapotranspiration in five representative climatic regimes. Results quantified the capabilities of green roofs in retaining rainfall and consequently in reducing discharges into sewer systems at an annual time scale. The role of substrate depth has been recognized to be crucial in determining green roofs retention performance, which in general increase from extensive to intensive settings. Looking at the

  11. The green roof dilemma - discussion of Francis and Lorimer (2011).

    Science.gov (United States)

    Henry, Alexandre; Frascaria-Lacoste, Nathalie

    2012-08-15

    Urban ecosystems are the most complex mosaics of vegetative land cover that can be found. In a recent paper, Francis and Lorimer (2011) evaluated the reconciliation potential of living roofs and walls. For these authors, these two techniques for habitat improvement have strong potential for urban reconciliation ecology. However they have some ecological and societal limitations such as the physical extreme environmental characteristics, the monetary investment and the cultural perceptions of urban nature. We are interested in their results and support their conclusions. However, for a considerable time, green roofs have been designed to provide urban greenery for buildings and the green roof market has only focused on extensive roof at a restricted scale within cities. Thus, we have strong doubts about the relevance of their use as possible integrated elements of the network. Furthermore, without dynamic progress in research and the implementation of well-thought-out policies, what will be the real capital gain from green roofs with respect to land-use complementation in cities? If we agree with Francis and Lorimer (2011) considering that urban reconciliation ecology between nature and citizens is a current major challenge, then "adaptive collaborative management" is a fundamental requirement.

  12. An environmental cost-benefit analysis of alternative green roofing strategies

    Science.gov (United States)

    Richardson, M.; William, R. K.; Goodwell, A. E.; Le, P. V.; Kumar, P.; Stillwell, A. S.

    2016-12-01

    Green roofs and cool roofs are alternative roofing strategies that mitigate urban heat island effects and improve building energy performance. Green roofs consist of soil and vegetation layers that provide runoff reduction, thermal insulation, and potential natural habitat, but can require regular maintenance. Cool roofs involve a reflective layer that reflects more sunlight than traditional roofing materials, but require additional insulation during winter months. This study evaluates several roofing strategies in terms of energy performance, urban heat island mitigation, water consumption, and economic cost. We use MLCan, a multi-layer canopy model, to simulate irrigated and non-irrigated green roof cases with shallow and deep soil depths during the spring and early summer of 2012, a drought period in central Illinois. Due to the dry conditions studied, periodic irrigation is implemented in the model to evaluate its effect on evapotranspiration. We simulate traditional and cool roof scenarios by altering surface albedo and omitting vegetation and soil layers. We find that both green roofs and cool roofs significantly reduce surface temperature compared to the traditional roof simulation. Cool roof temperatures always remain below air temperature and, similar to traditional roofs, require low maintenance. Green roofs remain close to air temperature and also provide thermal insulation, runoff reduction, and carbon uptake, but might require irrigation during dry periods. Due to the longer lifetime of a green roof compared to cool and traditional roofs, we find that green roofs realize the highest long term cost savings under simulated conditions. However, using longer-life traditional roof materials (which have a higher upfront cost) can help decrease this price differential, making cool roofs the most affordable option due to the higher maintenance costs associated with green roofs

  13. Modelling of green roof hydrological performance for urban drainage applications

    Science.gov (United States)

    Locatelli, Luca; Mark, Ole; Mikkelsen, Peter Steen; Arnbjerg-Nielsen, Karsten; Bergen Jensen, Marina; Binning, Philip John

    2014-11-01

    Green roofs are being widely implemented for stormwater management and their impact on the urban hydrological cycle can be evaluated by incorporating them into urban drainage models. This paper presents a model of green roof long term and single event hydrological performance. The model includes surface and subsurface storage components representing the overall retention capacity of the green roof which is continuously re-established by evapotranspiration. The runoff from the model is described through a non-linear reservoir approach. The model was calibrated and validated using measurement data from 3 different extensive sedum roofs in Denmark. These data consist of high-resolution measurements of runoff, precipitation and atmospheric variables in the period 2010-2012. The hydrological response of green roofs was quantified based on statistical analysis of the results of a 22-year (1989-2010) continuous simulation with Danish climate data. The results show that during single events, the 10 min runoff intensities were reduced by 10-36% for 5-10 years return period and 40-78% for 0.1-1 year return period; the runoff volumes were reduced by 2-5% for 5-10 years return period and 18-28% for 0.1-1 year return period. Annual runoff volumes were estimated to be 43-68% of the total precipitation. The peak time delay was found to greatly vary from 0 to more than 40 min depending on the type of event, and a general decrease in the time delay was observed for increasing rainfall intensities. Furthermore, the model was used to evaluate the variation of the average annual runoff from green roofs as a function of the total available storage and vegetation type. The results show that even a few millimeters of storage can reduce the mean annual runoff by up to 20% when compared to a traditional roof and that the mean annual runoff is not linearly related to the storage. Green roofs have therefore the potential to be important parts of future urban stormwater management plans.

  14. Who governs climate adaptation? Getting green roofs for stormwater retention off the ground

    NARCIS (Netherlands)

    Mees, H.L.P.; Driessen, P.P.J.; Runhaar, H.A.C.; Stamatelos, J.

    2013-01-01

    Green roofs are an innovative solution for urban stormwater management. This paper examines governance arrangements for green roofs as a ‘no-regrets’ climate adaptation measure in five cities. We analysed who governs green roofs, why and with what outcome. Our results show that hierarchical and mark

  15. Entire cities could benefit from green roofs : Heleen Mees is investigating how five metropolises are greenifying their roofs

    NARCIS (Netherlands)

    Mees, Heleen

    2014-01-01

    Rotterdam is making good progress with its creation of green roofs. Heleen Mees, researcher at Utrecht University, drew this conclusion from her research, in which she compared the green roof policy of four different cities with that of Rotterdam. Rotterdam awards grants to those wishing to create a

  16. Green Roof Research through EPA's Regional Applied Research Effort - slides

    Science.gov (United States)

    The U.S. Environmental Protection Agency’s (EPA) Regional Applied Research Effort (RARE) allows the Regions of the EPA to choose research projects to be performed in partnership with EPA’s Office of Research and Development (ORD). Over the last decade, several green roof projects...

  17. Retrofitted green roofs and walls and improvements in thermal comfort

    Science.gov (United States)

    Feitosa, Renato Castiglia; Wilkinson, Sara

    2017-06-01

    Increased urbanization has led to a worsening in the quality of life for many people living in large cities in respect of the urban heat island effect and increases of indoor temperatures in housing and other buildings. A solution may be to retrofit existing environments to their former conditions, with a combination of green infrastructures applied to existing walls and rooftops. Retrofitted green roofs may attenuate housing temperature. However, with tall buildings, facade areas are much larger compared to rooftop areas, the role of green walls in mitigating extreme temperatures is more pronounced. Thus, the combination of green roofs and green walls is expected to promote a better thermal performance in the building envelope. For this purpose, a modular vegetated system is adopted for covering both walls and rooftops. Rather than temperature itself, the heat index, which comprises the combined effect of temperature and relative humidity is used in the evaluation of thermal comfort in small scale experiments performed in Sydney - Australia, where identical timber framed structures prototypes (vegetated and non-vegetated) are compared. The results have shown a different understanding of thermal comfort improvement regarding heat index rather than temperature itself. The combination of green roof and walls has a valid role to play in heat index attenuation.

  18. Evaluation of green roof as green technology for urban stormwater quantity and quality controls

    Science.gov (United States)

    Kok, K. H.; Sidek, L. M.; Abidin, M. R. Z.; Basri, H.; Muda, Z. C.; Beddu, S.

    2013-06-01

    Promoting green design, construction, reconstruction and operation of buildings has never been more critical than now due to the ever increasing greenhouse gas emissions and rapid urbanizations that are fuelling climate change more quickly. Driven by environmental needs, Green Building Index (GBI) was founded in Malaysia to drive initiative to lead the property industry towards becoming more environment-friendly. Green roof system is one of the assessment criteria of this rating system which is under category of sustainable site planning and management. An extensive green roof was constructed in Humid Tropics Center (HTC) Kuala Lumpur as one of the components for Stormwater Management Ecohydrology (SME) in order to obtain scientific data of the system. This paper evaluates the performance of extensive green roof at Humid Tropics Center with respect to urban heat island mitigation and stormwater quantity and quality controls. Findings indicate that there was a reduction of around 1.5°C for indoor temperature of the building after installation of green roof. Simulations showed that the peak discharge was reduced up to 24% relative to impervious brown roof. The results show an increment of pH and high concentration of phosphate for the runoff generated from the green roof and the runoff water quality ranged between class I and II under INWQS.

  19. Green roof adoption in atlanta, georgia: the effects of building characteristics and subsidies on net private, public, and social benefits.

    Science.gov (United States)

    Mullen, Jeffrey D; Lamsal, Madhur; Colson, Greg

    2013-10-01

    This research draws on and expands previous studies that have quantified the costs and benefits associated with conventional roofs versus green roofs. Using parameters from those studies to define alternative scenarios, we estimate from a private, public, and social perspective the costs and benefits of installing and maintaining an extensive green roof in Atlanta, GA. Results indicate net private benefits are a decreasing function of roof size and vary considerably across scenarios. In contrast, net public benefits are highly stable across scenarios, ranging from $32.49 to $32.90 m(-2). In addition, we evaluate two alternative subsidy regimes: (i) a general subsidy provided to every building that adopts a green roof and (ii) a targeted subsidy provided only to buildings for which net private benefits are negative but net public benefits are positive. In 6 of the 12 general subsidy scenarios the optimal public policy is not to offer a subsidy; in 5 scenarios the optimal subsidy rate is between $20 and $27 m(-2); and in 1 scenario the optimal rate is $5 m(-2). The optimal rate with a targeted subsidy is between $20 and $27 m(-2) in 11 scenarios and no subsidy is optimal in the twelfth. In most scenarios, a significant portion of net public benefits are generated by buildings for which net private benefits are positive. This suggests a policy focused on information dissemination and technical assistance may be more cost-effective than direct subsidy payments.

  20. Digging the New York City Skyline: soil fungal communities in green roofs and city parks.

    Science.gov (United States)

    McGuire, Krista L; Payne, Sara G; Palmer, Matthew I; Gillikin, Caitlyn M; Keefe, Dominique; Kim, Su Jin; Gedallovich, Seren M; Discenza, Julia; Rangamannar, Ramya; Koshner, Jennifer A; Massmann, Audrey L; Orazi, Giulia; Essene, Adam; Leff, Jonathan W; Fierer, Noah

    2013-01-01

    In urban environments, green roofs provide a number of benefits, including decreased urban heat island effects and reduced energy costs for buildings. However, little research has been done on the non-plant biota associated with green roofs, which likely affect their functionality. For the current study, we evaluated whether or not green roofs planted with two native plant communities in New York City functioned as habitats for soil fungal communities, and compared fungal communities in green roof growing media to soil microbial composition in five city parks, including Central Park and the High Line. Ten replicate roofs were sampled one year after planting; three of these roofs were more intensively sampled and compared to nearby city parks. Using Illumina sequencing of the fungal ITS region we found that green roofs supported a diverse fungal community, with numerous taxa belonging to fungal groups capable of surviving in disturbed and polluted habitats. Across roofs, there was significant biogeographical clustering of fungal communities, indicating that community assembly of roof microbes across the greater New York City area is locally variable. Green roof fungal communities were compositionally distinct from city parks and only 54% of the green roof taxa were also found in the park soils. Phospholipid fatty acid analysis revealed that park soils had greater microbial biomass and higher bacterial to fungal ratios than green roof substrates. City park soils were also more enriched with heavy metals, had lower pH, and lower quantities of total bases (Ca, K, and Mg) compared to green roof substrates. While fungal communities were compositionally distinct across green roofs, they did not differentiate by plant community. Together, these results suggest that fungi living in the growing medium of green roofs may be an underestimated component of these biotic systems functioning to support some of the valued ecological services of green roofs.

  1. Digging the New York City Skyline: soil fungal communities in green roofs and city parks.

    Directory of Open Access Journals (Sweden)

    Krista L McGuire

    Full Text Available In urban environments, green roofs provide a number of benefits, including decreased urban heat island effects and reduced energy costs for buildings. However, little research has been done on the non-plant biota associated with green roofs, which likely affect their functionality. For the current study, we evaluated whether or not green roofs planted with two native plant communities in New York City functioned as habitats for soil fungal communities, and compared fungal communities in green roof growing media to soil microbial composition in five city parks, including Central Park and the High Line. Ten replicate roofs were sampled one year after planting; three of these roofs were more intensively sampled and compared to nearby city parks. Using Illumina sequencing of the fungal ITS region we found that green roofs supported a diverse fungal community, with numerous taxa belonging to fungal groups capable of surviving in disturbed and polluted habitats. Across roofs, there was significant biogeographical clustering of fungal communities, indicating that community assembly of roof microbes across the greater New York City area is locally variable. Green roof fungal communities were compositionally distinct from city parks and only 54% of the green roof taxa were also found in the park soils. Phospholipid fatty acid analysis revealed that park soils had greater microbial biomass and higher bacterial to fungal ratios than green roof substrates. City park soils were also more enriched with heavy metals, had lower pH, and lower quantities of total bases (Ca, K, and Mg compared to green roof substrates. While fungal communities were compositionally distinct across green roofs, they did not differentiate by plant community. Together, these results suggest that fungi living in the growing medium of green roofs may be an underestimated component of these biotic systems functioning to support some of the valued ecological services of green roofs.

  2. Green roof impact on the hydrological cycle components

    Science.gov (United States)

    Lamera, Carlotta; Rulli, Maria Cristina; Becciu, Gianfranco; Rosso, Renzo

    2013-04-01

    In the last decades the importance of storm water management in urban areas has increased considerably, due to both urbanization extension and to a greater concern for environment pollution. Traditional storm water control practices, based on the "all to the sewer" attitude, rely on conveyance to route storm water runoff from urban impervious surfaces towards the nearby natural water bodies. In recent years, infiltration facilities are receiving an increasing attention, due to their particular efficiency in restoring a balance in hydrological cycle quite equal to quite pre-urbanization condition. In particular, such techniques are designed to capture, temporarily retain and infiltrate storm water, promote evapotranspiration and harvest water at the source, encouraging in general evaporation, evapotranspiration, groundwater recharge and the re-use of storm water. Green roofs are emerging as an increasingly popular Sustainable Urban Drainage Systems (SUDS) technique for urban storm water management. Indeed, they are able to operate hydrologic control over storm water runoff: they allow a significant reduction of peak flows and runoff volumes collected by drainage system, with a consequent reduction of flooding events and pollution masses discharges by CSO. Furthermore green roofs have a positive influence on the microclimate in urban areas by helping in lower urban air temperatures and mitigate the heat island effect. Last but not least, they have the advantage of improving the thermal insulation of buildings, with significant energy savings. A detailed analysis of the hydrological dynamics, connected both with the characteristics of the climatic context and with the green roof technical design, is essential in order to obtain a full characterization of the hydrologic behavior of a green roof system and its effects on the urban water cycle components. The purpose of this paper is to analysis the hydrological effects and urban benefits of the vegetation cover of a

  3. Surface energy balance of an extensive green roof as quantified by full year eddy-covariance measurements.

    Science.gov (United States)

    Heusinger, Jannik; Weber, Stephan

    2017-01-15

    Green roofs are discussed as a promising type of green infrastructure to lower heat stress in cities. In order to enhance evaporative cooling, green roofs should ideally have similar Bowen ratio (β=sensible heat flux/latent heat flux) characteristics such as rural sites, especially during summer periods with high air temperatures. We use the eddy-covariance (EC) method to quantify the energy balance of an 8600m(2) extensive, non-irrigated green roof at the Berlin Brandenburg Airport, Germany over a full annual cycle. To understand the influence of water availability on green roof-atmosphere energy exchange, we studied dry and wet periods and looked into functional relationships between leaf area, volumetric water content (VWC) of the substrate, shortwave radiation and β. The surface energy balance was dominated by turbulent heat fluxes in comparison to conductive substrate heat fluxes. The Bowen ratio was slightly below unity on average but highly variable due to ambient meteorology and substrate water availability, i.e. β increased to 2 in the summer season. During dry periods mean daytime β was 3, which is comparable to typical values of urban instead of rural sites. In contrast, mean daytime β was 0.3 during wet periods. Following a summer wet period the green roof maximum daily evapotranspiration (ET) was 3.3mm, which is a threefold increase with respect to the mean summer ET. A multiple regression model indicated that the substrate VWC at the present site has to be >0.11m(3)m(-3) during summer high insolation periods (>500Wm(-2)) in order to maintain favourable green roof energy partitioning, i.e. mid-day βgreen roofs can be significantly optimised by using sustainable irrigation approaches.

  4. THE INFLUENCE THE EXTENSIVE GREEN ROOFS ON THE OUTFLOW RAINWATER TO THE SEWAGE SYSTEM

    Directory of Open Access Journals (Sweden)

    Maciej Mrowiec

    2015-10-01

    Full Text Available In times of rapid urbanization and climate change has drawn more attention to stormwater runoff to sewer systems. The phenomenon of flooding in urban areas have become increasingly common as a result of heavy rains. Sewage systems in such a short time are not able to accept such a large amount of rainwater flowing on the site, which we experience the phenomenon of rainfall flowing down the street in excessive amounts. The problem of such phenomena can be solved by the development of green roof technology. Even in its simplest form that extensive green roof is able to delay outflow, and store in its entirety falling falls on the area. Everything depends on the layers and the size of the roof. The research study presented at two mini green roof, an area of 1.44 m2. Both cases have different layers. One of them has a layer of non-woven filter layer, the substrate and vegetation. The second station is built of layers of drainage, filter layer, a layer of substrate and vegetation. For experimental purposes a rain shower were used for testing, which allows to calibrate the right amount of water at a specified time. In the research of precipitation 10, 15 and 20-minute tested. On the bench number 1 a reduction in the range of 48.9 to 97.5% was achieved. The second experiment stand showed a higher retention capacity ranged from 74.5 to 94.7%. We concluded that the use of extensive green roofs in cities can help reduce storm water runoff from impervious surfaces.

  5. Effect of green roofs on air temperature; measurement study of well-watered and dry conditions

    Science.gov (United States)

    Solcerova, Anna; van de Ven, Frans; Wang, Mengyu; van de Giesen, Nick

    2016-04-01

    Rapid urbanization and increasing number and duration of heat waves poses a need for understanding urban climate and ways to mitigate extremely high temperatures. One of repeatedly suggested and often investigated methods to moderate the so called urban heat island are green roofs. This study investigates several extensive green roofs in Utrecht (NL) and their effect on air temperature right above the roof surface. Air temperature was measured 15 and 30 cm above the roof surface and also in the substrate. We show that under normal condition is air above green roof, compared to white gravel roof, colder at night and warmer during day. This suggest that green roofs might help decrease air temperatures at night, when the urban heat island is strongest, but possibly contribute to high temperatures during daytime. We also measured situation when the green roofs wilted and dried out. Under such conditions green roof exhibits more similar behavior to conventional white gravel roof. Interestingly, pattern of soil temperature remains almost the same for both dry and well-prospering green roof, colder during day and warmer at night. As such, green roof works as a buffer of diurnal temperature changes.

  6. Evaluation of Green Roof Water Quantity and Quality Performance in an Urban Climate

    Science.gov (United States)

    In this report we present an analysis of water benefits from an array of observed green roof and control (non-vegetated) roof project sites throughout NYC. The projects are located on a variety of building sites and represent a diverse set of available extensive green roof instal...

  7. Positive effects of vegetation: urban heat island and green roofs.

    Science.gov (United States)

    Susca, T; Gaffin, S R; Dell'osso, G R

    2011-01-01

    This paper attempts to evaluate the positive effects of vegetation with a multi-scale approach: an urban and a building scale. Monitoring the urban heat island in four areas of New York City, we have found an average of 2 °C difference of temperatures between the most and the least vegetated areas, ascribable to the substitution of vegetation with man-made building materials. At micro-scale, we have assessed the effect of surface albedo on climate through the use of a climatological model. Then, using the CO(2) equivalents as indicators of the impact on climate, we have compared the surface albedo, and the construction, replacement and use phase of a black, a white and a green roof. By our analyses, we found that both the white and the green roofs are less impactive than the black one; with the thermal resistance, the biological activity of plants and the surface albedo playing a crucial role.

  8. Modeling Košice Green Roofs Maps

    Science.gov (United States)

    Poorova, Zuzana; Vranayova, Zuzana

    2017-06-01

    The need to house population in urban areas is expected to rise to 66% in 2050, according to United Nations. The replacement of natural permeable green areas with concrete constructions and hard surfaces will be noticed. The densification of existing built-up areas is responsible for the decreasing vegetation, which results in the lack of evapotranspiration cooling the air. Such decreasing vegetation causes urban heat islands. Since roofs and pavements have a very low albedo, they absorb a lot of sunlight. Several studies have shown that natural and permeable surfaces, as in the case of green roofs, can play crucial role in mitigating this negative climate phenomenon and providing higher efficiency for the building, leading to savings. Such as water saving, what is the main idea of this research.

  9. Assessment of green roof systems in terms of water and energy balance

    Directory of Open Access Journals (Sweden)

    Mert Ekşi

    2016-01-01

    Full Text Available Green roofs concept term is used for extensive green roofs which are planted with herbaceous plants that can be adapted into changeable environmental conditions on a shallow substrate layer, require minimal maintenance, installed for their benefits to building and urban scale. Main objective of this study is to determine the characteristics of a green roof such as thermal insulation, water holding capacity, runoff characteristics, plant growth and its interaction with environmental factors in Istanbul climate conditions by performing comparative measurements. In this study, a research site (IU Green Roof Research Station was founded to assess water and energy balance of green roofs. Thus, a typical green roof was evaluated in terms of water and energy balance and its interaction with the building and city was determined. energy efficiency of green roof system was 77% higher than reference roof. Temperature fluctuations on green roof section of the roof were 79% lower. In addition, green roof retained 12,8% - 100% of precipitation and delayed runoff up to 23 hours depending on water content of substrate.

  10. Green Roofs: Standardization and Quality Control of Processes in Green Construction

    Directory of Open Access Journals (Sweden)

    Korol Elena

    2017-01-01

    Full Text Available The article considers the problems of standardization and quality control of processes in the construction, improvement of integrated safety of buildings and the implementation of innovative green building technologies, the use of national standards as well as international rating systems for green buildings evaluation. This is one of the priority directions in development of the modern construction. The aim of this study is the analysis of the green roof systems and international standards, which were carried out in the green building industry. The authors have studied traditional and innovative solutions of rational using natural resources and energy, the green roof system with integration of supported solar and wind energy collecting and converting devices and of irrigation system. Some studies provide evidence for the benefits of the modular green roof system in urban green space with microclimate differences. This article presents a new research which advances our knowledge of the economic and environmental services provided by the green roof system. Research reported here also considers the analysis of the Russian and international legislation of the quality control of processes in green construction.

  11. A modelling study of long term green roof retention performance.

    Science.gov (United States)

    Stovin, Virginia; Poë, Simon; Berretta, Christian

    2013-12-15

    This paper outlines the development of a conceptual hydrological flux model for the long term continuous simulation of runoff and drought risk for green roof systems. A green roof's retention capacity depends upon its physical configuration, but it is also strongly influenced by local climatic controls, including the rainfall characteristics and the restoration of retention capacity associated with evapotranspiration during dry weather periods. The model includes a function that links evapotranspiration rates to substrate moisture content, and is validated against observed runoff data. The model's application to typical extensive green roof configurations is demonstrated with reference to four UK locations characterised by contrasting climatic regimes, using 30-year rainfall time-series inputs at hourly simulation time steps. It is shown that retention performance is dependent upon local climatic conditions. Volumetric retention ranges from 0.19 (cool, wet climate) to 0.59 (warm, dry climate). Per event retention is also considered, and it is demonstrated that retention performance decreases significantly when high return period events are considered in isolation. For example, in Sheffield the median per-event retention is 1.00 (many small events), but the median retention for events exceeding a 1 in 1 yr return period threshold is only 0.10. The simulation tool also provides useful information about the likelihood of drought periods, for which irrigation may be required. A sensitivity study suggests that green roofs with reduced moisture-holding capacity and/or low evapotranspiration rates will tend to offer reduced levels of retention, whilst high moisture-holding capacity and low evapotranspiration rates offer the strongest drought resistance.

  12. Models for acoustical properties of green roof materials

    OpenAIRE

    2011-01-01

    To predict the acoustical effects of green roof structures it is necessary to be able to model the acoustical properties of their materials including gravel. For time domain calculations it is convenient to use the phenomenological model due to Zwikker and Kosten. However this phenomenological model is related to a low frequency/high flow resistivity approximation of more ‘exact’ identical pore models. The results of fitting predictions to short range level difference data and to impedance da...

  13. Manipulating soil microbial communities in extensive green\\ud roof substrates

    OpenAIRE

    Molineux, Chloe; Connop, Stuart; Gange, Alan

    2014-01-01

    There has been very little investigation into the soil microbial community on green roofs, yet this below ground habitat is vital for ecosystem functioning. Green roofs are often harsh environments that would greatly benefit from having a healthy microbial system, allowing efficient nutrient cycling and a degree of drought tolerance in dry summer months. To test if green roof microbial communities could be manipulated,we added mycorrhizal fungi and a microbial mixture (‘compost tea’) to green...

  14. Study of water infiltration in a lightweight green roof substrate

    Science.gov (United States)

    Tomankova, Klara; Holeckova, Martina; Jelinkova, Vladimira; Snehota, Michal

    2015-04-01

    Green roofs have a positive impact on the environment (e.g. improving microclimate and air quality in cities, reducing solar absorbance and storm water). A laboratory infiltration experiment was conducted on the narrow flume serving as 2D vertical model of a green roof. The lightweight Optigreen substrate Type M was used (depth of 20 cm). The front wall of the flume was transparent and inspected by digital camera. The experiment was designed to measure pressure head, volumetric water content and calculate water retention in the substrate. Experiment comprised three artificial rainfall intensities with different values of initial water content of the substrate. The experimental results confirmed that green roofs have the ability to retain rainwater and thus have a beneficial effect on reducing runoff. In the experiment with the artificial 10 minutes rainfall event (total precipitation of 29 mm), the air dry substrate retained 95.9 % of precipitation. On the other hand for moist initial condition 4.2 % of precipitations amount was captured in the substrate. Additionally, the analysis of images taken during the experiment confirmed preferential flow and uneven advancement of the wetting front. The research was realized as a part of the University Centre for Energy Efficient Buildings supported by the EU and with financial support from the Czech Science Foundation under project number 14-10455P.

  15. Optimizing the building envelopes with green roofs : a discussion of architectural and energy performance requirements

    Energy Technology Data Exchange (ETDEWEB)

    Hagerman, J. [Columbia Univ., New York, NY (United States). Dept. of Civil Engineering]|[Rafael Vinoly Architects, New York, NY (United States); Hodge, D. [Rafael Vinoly Architects, New York, NY (United States)

    2006-07-01

    This paper provided recommendations for optimized green roof technologies inspired by an architect firm's involvement in designing a 255,000 square foot green roof on top of the Howard Hughes Medical Institute's Janelia Farm Research Campus in Virginia. During the course of the green roof construction and installation, the architects found that green roofs needed design flexibility to meet their conceptual design requirements. It was suggested that the use of a modular system might allow for easier inspection access as well as the ability for the planting material to be reconfigured. It was noted that green roof systems can sometimes conflict with water management strategies of the building envelope. Green roof component lists do not make reference to the layers of construction within the building envelope, as it is often assumed that they are irrelevant to green roof design. Modular products offer Architects flexibility in design and maintenance, and products can be incorporated into more sophisticated water management details, offering simplicity of design, ease of installation, and ease of roof membrane inspection. A thermal analysis of modular and monolithic roof assemblies was conducted which showed that the assemblies contributed very little to the overall thermal insulation envelope when the positive thermal benefits of the green roof failed. It was recommended that green roof installations should be designed to sit directly on top of the roof membranes to replace the building's insulation envelope. Foamglas was proposed as a material for building insulation and to prevent root penetration. An evaluation of the R-values of various green roof systems at failure was also provided to give guidance to Architects incorporating green roofs in building envelopes. 3 refs., 3 tabs., 8 figs.

  16. Sedum-dominated green-roofs in a semi-arid region increase CO2 concentrations during the dry season.

    Science.gov (United States)

    Agra, Har'el; Klein, Tamir; Vasl, Amiel; Shalom, Hadar; Kadas, Gyongyver; Blaustein, Leon

    2017-04-15

    Green roofs are expected to absorb and store carbon in plants and soils and thereby reduce the high CO2 concentration levels in big cities. Sedum species, which are succulent perennials, are commonly used in extensive green roofs due to their shallow root system and ability to withstand long water deficiencies. Here we examined CO2 fixation and emission rates for Mediterranean Sedum sediforme on green-roof experimental plots. During late winter to early spring, we monitored CO2 concentrations inside transparent tents placed over 1m(2) plots and followed gas exchange at the leaf level using a portable gas-exchange system. We found high rates of CO2 emission at daytime, which is when CO2 concentration in the city is the highest. Both plot- and leaf-scale measurements showed that these CO2 emissions were not fully compensated by the nighttime uptake. We conclude that although carbon sequestration may only be a secondary benefit of green roofs, for improving this ecosystem service, other plant species than Sedum should also be considered for use in green roofs, especially in Mediterranean and other semi-arid climates.

  17. Impact of green roofs on stormwater quality in a South Australian urban environment.

    Science.gov (United States)

    Razzaghmanesh, M; Beecham, S; Kazemi, F

    2014-02-01

    Green roofs are an increasingly important component of water sensitive urban design systems and can potentially improve the quality of urban runoff. However, there is evidence that they can occasionally act as a source rather than a sink for pollutants. In this study, the water quality of the outflow from both intensive and extensive green roof systems were studied in the city of Adelaide, South Australia over a period of nine months. The aim was to examine the effects of different green roof configurations on stormwater quality and to compare this with runoff from aluminium and asphalt roofs as control surfaces. The contaminant concentrations in runoff from both intensive and extensive green roofs generally decreased during the study period. A comparison between the two types of green roof showed that except for some events for EC, TDS and chloride, the values of the parameters such as pH, turbidity, nitrate, phosphate and potassium in intensive green roof outflows were higher than in the outflows from the extensive green roofs. These concentrations were compared to local, state, national and international water quality guidelines in order to investigate the potential for outflow runoff from green roofs to be reused for potable and non-potable purposes. The study found that green roof outflow can provide an alternative water source for non-potable purposes such as urban landscape irrigation and toilet flushing.

  18. Suspended solids in and turbidity of runoff from green roofs.

    Science.gov (United States)

    Morgan, Susan; Alyaseri, Isam; Retzlaff, William

    2011-01-01

    Green roof technology is used to reduce the quantity of stormwater runoff, but questions remain regarding its impact on quality. This study analyzed the total suspended solids (TSS) in and the turbidity of runoff from green roof growth media mixed with composted pine bark in an indoor pot study. The results showed that there were elevated levels of TSS and turbidity in the runoff that decreased over time for all growth media. Both TSS and turbidity are affected by the type of growth media. Lava and haydite had higher mean TSS and mean turbidity than arkalyte and bottom ash. Vegetation reduced the mean turbidity and mean TSS of the first flush by an average of 53% and 63%, respectively, but generally had no statistically significant effect thereafter. The results indicate that the media, rather than the vegetation, has a greater effect on TSS and turbidity in the runoff In areas with stringent water quality regulations for stormwater runoff from developed sites, media selection may be an important consideration. It may also be necessary in these regions to ensure that the roof is planted prior to receiving rainfall to minimize the first flush effect and that any irrigation does not result in runoff.

  19. GREEN ROOFS AS A TOOL FOR IMPROVEMENT THE STORMWATER MANAGEMENT IN URBAN AREAS

    Directory of Open Access Journals (Sweden)

    Ewa Burszta-Adamiak

    2014-10-01

    Full Text Available The interest in green roof technologies is increasing due to the many tangible benefits that allow to provide. One of them is the ability to improve stormwater management in urban areas, because construction of green roofs can retain and delay in runoff . Due to the fact that the market of green roofs in Poland is relatively young, there is still a need for research to provide detailed information about green roof hydrologic performance in the national climate conditions. The objective of this study is to present the research results on retention capacity of green roofs, carried out at the Wroclaw University of Life Sciences. The results show that the possibility of water retention is considerably improved at green roofs when antecedent dry weather period lasts longer than one day and the rainfall depth does not exceed 10 mm / day.

  20. Towards a generic rainfall-runoff model for green roofs.

    Science.gov (United States)

    Kasmin, H; Stovin, V R; Hathway, E A

    2010-01-01

    A simple conceptual model for green roof hydrological processes is shown to reproduce monitored data, both during a storm event, and over a longer continuous simulation period. The model comprises a substrate moisture storage component and a transient storage component. Storage within the substrate represents the roof's overall stormwater retention capacity (or initial losses). Following a storm event the retention capacity is restored by evapotranspiration (ET). However, standard methods for quantifying ET do not exist. Monthly ET values are identified using four different approaches: analysis of storm event antecedent dry weather period and initial losses data; calibration of the ET parameter in a continuous simulation model; use of the Thornthwaite ET formula; and direct laboratory measurement of evaporation. There appears to be potential to adapt the Thornthwaite ET formula to provide monthly ET estimates from local temperature data. The development of a standardized laboratory test for ET will enable differences resulting from substrate characteristics to be quantified.

  1. Public versus Private Incentives to Invest in Green Roofs: A Cost Benefit Analysis for Flanders.

    OpenAIRE

    Claus, Karla; Rousseau, Sandra

    2010-01-01

    By means of a cost benefit analysis, we compare public and private incentives to invest in extensive green roofs in urban areas. From the comparison of these public and private incentives we find that subsidies for green roofs are socially desirable and that subsidies are actually needed to convince potential private investors to construct green roofs. Specifically, we estimate the costs and benefits associated with an investment project in Groot-Bijgaarden (Belgium) where a real estate inves...

  2. Habitat connectivity shapes urban arthropod communities: the key role of green roofs.

    Science.gov (United States)

    Braaker, S; Ghazoul, J; Obrist, M K; Moretti, M

    2014-04-01

    The installation of green roofs, defined here as rooftops with a shallow soil cover and extensive vegetation, has been proposed as a possible measure to mitigate the loss of green space caused by the steady growth of cities. However, the effectiveness of green roofs in supporting arthropod communities, and the extent to which they facilitate connectivity of these communities within the urban environment is currently largely unknown. We investigated the variation of species community composition (beta diversity) of four arthropod groups with contrasting mobility (Carabidae, Araneae, Curculionidae, and Apidae) on 40 green roofs and 40 extensively managed green sites on the ground in the city of Zurich, Switzerland. With redundancy analysis and variation partitioning, we (1) disentangled the relative importance of local environmental conditions, the surrounding land cover composition, and habitat connectivity on species community composition, (2) searched for specific spatial scales of habitat connectivity for the different arthropod groups, and (3) discussed the ecological and functional value of green roofs in cities. Our study revealed that on green roofs community composition of high-mobility arthropod groups (bees and weevils) were mainly shaped by habitat connectivity, while low-mobility arthropod groups (carabids and spiders) were more influenced by local environmental conditions. A similar but less pronounced pattern was found for ground communities. The high importance of habitat connectivity in shaping high-mobility species community composition indicates that these green roof communities are substantially connected by the frequent exchange of individuals among surrounding green roofs. On the other hand, low-mobility species communities on green roofs are more likely connected to ground sites than to other green roofs. The integration of green roofs in urban spatial planning strategies has great potential to enable higher connectivity among green spaces, so

  3. Spatially dependent biotic and abiotic factors drive survivorship and physical structure of green roof vegetation.

    Science.gov (United States)

    Aloisio, Jason M; Palmer, Matthew I; Giampieri, Mario A; Tuininga, Amy R; Lewis, James D

    2017-01-01

    Plant survivorship depends on biotic and abiotic factors that vary at local and regional scales. This survivorship, in turn, has cascading effects on community composition and the physical structure of vegetation. Survivorship of native plant species is variable among populations planted in environmentally stressful habitats like urban roofs, but the degree to which factors at different spatial scales affect survivorship in urban systems is not well understood. We evaluated the effects of biotic and abiotic factors on survivorship, composition, and physical structure of two native perennial species assemblages, one characterized by a mixture of C4 grasses and forbs (Hempstead Plains, HP) and one characterized by a mixture of C3 grasses and forbs (Rocky Summit, RS), that were initially sown at equal ratios of growth forms (5:1:4; grass, N-fixing forb and non-N-fixing forb) in replicate 2-m(2) plots planted on 10 roofs in New York City (New York, USA). Of 24 000 installed plants, 40% survived 23 months after planting. Within-roof factors explained 71% of variation in survivorship, with biotic (species identity and assemblage) factors accounting for 54% of the overall variation, and abiotic (growing medium depth and plot location) factors explaining 17% of the variation. Among-roof factors explained 29% of variation in survivorship and increased solar radiation correlated with decreased survivorship. While growing medium properties (pH, nutrients, metals) differed among roofs there was no correlation with survivorship. Percent cover and sward height increased with increasing survivorship. At low survivorship, cover of the HP assemblage was greater compared to the RS assemblage. Sward height of the HP assemblage was about two times greater compared to the RS assemblage. These results highlight the effects of local biotic and regional abiotic drivers on community composition and physical structure of green roof vegetation. As a result, initial green roof plant

  4. The Research Progress of Roof Greening%屋顶绿化研究进展

    Institute of Scientific and Technical Information of China (English)

    杨雪; 吴煜; 郑玉贤

    2014-01-01

    The article mainly summarizes the present research situation of roof greening in recent years ,including roof greening's classification ,and function and the research of the roof greening plants'resistance selection .In the end ,the article particularly speculates roof greening plant's resistance selection research .%综述了屋顶绿化近几年的研究现状,包括屋顶绿化的分类、功能及屋顶绿化植物的抗性筛选研究。重点针对屋顶绿化植物的抗性筛选研究进行了展望。

  5. Evaluation of Green Roof Plants and Materials for Semi-Arid Climates

    Science.gov (United States)

    Abstract While green roof systems have proven to be highly effective in the evaporative cooling of buildings, reduction of roof top temperatures, protection of roof membranes from solar radiation degradation, reducing stormwater runoff, as well as beautification of the urban roo...

  6. Establishment and performance of an experimental green roof under extreme climatic conditions.

    Science.gov (United States)

    Klein, Petra M; Coffman, Reid

    2015-04-15

    Green roofs alter the surface energy balance and can help in mitigating urban heat islands. However, the cooling of green roofs due to evapotranspiration strongly depends on the climatic conditions, and vegetation type and density. In the Southern Central Plains of the United States, extreme weather events, such as high winds, heat waves and drought conditions pose challenges for successful implementation of green roofs, and likely alter their standard performance. The National Weather Center Experimental Green Roof, an interdisciplinary research site established in 2010 in Norman, OK, aimed to investigate the ecological performance and surface energy balance of green roof systems. Starting in May 2010, 26 months of vegetation studies were conducted and the radiation balance, air temperature, relative humidity, and buoyancy fluxes were monitored at two meteorological stations during April-October 2011. The establishment of a vegetative community trended towards prairie plant dominance. High mortality of succulents and low germination of grasses and herbaceous plants contributed to low vegetative coverage. In this condition succulent diversity declined. Bouteloua gracilis and Delosperma cooperi showed typological dominance in harsh climatic conditions, while Sedum species experienced high mortality. The plant community diversified through volunteers such as Euphorbia maculate and Portulaca maculate. Net radiation measured at a green-roof meteorological station was higher than at a control station over the original, light-colored roofing material. These findings indicate that the albedo of the green roof was lower than the albedo of the original roofing material. The low vegetative coverage during the heat and drought conditions in 2011, which resulted in the dark substrate used in the green roof containers being exposed, likely contributed to the low albedo values. Nevertheless, air temperatures and buoyancy fluxes were often lower over the green roof indicating

  7. Green roof and storm water management policies: monitoring experiments on the ENPC Blue Green Wave

    Science.gov (United States)

    Versini, Pierre-Antoine; Gires, Auguste; Fitton, George; Tchiguirinskaia, Ioulia; Schertzer, Daniel

    2015-04-01

    Currently widespread in new urban projects, green roofs have shown a positive impact on urban runoff at the building/parcel scale. Nevertheless, there is no specific policy promoting their implementation neither in Europe nor in France. Moreover they are not taken into account (and usually considered as an impervious area) in the sizing of a retention basin for instance. An interesting example is located in the heart of the Paris-East Cluster for Science and Technology (Champs-sur-Marne, France). Since 2013 a large (1 ha) wavy-form vegetated roof (called bleu green wave) is implemented. Green roof area and impervious areas are connected to a large retention basin, which has been oversized. The blue green wave represents a pioneering site where an initially amenity (decorative) design project has been transformed into a research oriented one. Several measurement campaigns have been conducted to investigate and better understand the hydrological behaviour of such a structure. Rainfall, humidity, wind velocity, water content and temperature have been particularly studied. The data collected are used for several purposes: (i) characterize the spatio-temporal variability of the green roof response, (ii) calibrate and validate a specific model simulating its hydrological behavior. Based on monitoring and modeling results, green roof performances will be quantified. It will be possible to estimate how they can reduce stormwater runoff and how these performances can vary in space and in time depending on green roof configuration, rainfall event characteristics and antecedent conditions. These quantified impacts will be related to regulation rules established by stormwater managers in order to connect the parcel to the sewer network. In the particular case of the building of a retention basin, the integration of green roof in the sizing of the basin will be studied. This work is funded by the European Blue Green Dream project (http://bgd.org.uk/, funded by Climate

  8. Life, death, and resurrection on a green roof in Toronto

    Energy Technology Data Exchange (ETDEWEB)

    McGlade, T. [Perennial Gardens Corp., Toronto, ON (Canada)

    2004-07-01

    The Sears warehouse building in Toronto was constructed in 1910 and has been converted to a 400 unit loft condominium. Perennial Gardens Corporation was hired to landscape a rooftop garden on the huge open roof area to provide a place for residents to barbecue and relax. The process began with engineers placing the venting for the drains directly into the planting beds and addressing roof drain and sloping issues. There were many physical aspects which caused a variety of problems with this project, namely high wind velocity with a swirling effect which meant that all trees had to be tripod staked; soil erosion due to the wind; the plants which were mostly plugs or 4 inch pots contained soil which was not compatible with the sopraflor used through the rooftop and a major problem with dogs using the rooftop area. This landscape project demonstrated that not all perennials are suited for a green roof. The original planting list was provided along with problems encountered. 5 figs.

  9. A generic hydrological model for a green roof drainage layer.

    Science.gov (United States)

    Vesuviano, Gianni; Stovin, Virginia

    2013-01-01

    A rainfall simulator of length 5 m and width 1 m was used to supply constant intensity and largely spatially uniform water inflow events to 100 different configurations of commercially available green roof drainage layer and protection mat. The runoff from each inflow event was collected and sampled at one-second intervals. Time-series runoff responses were subsequently produced for each of the tested configurations, using the average response of three repeat tests. Runoff models, based on storage routing (dS/dt = I-Q) and a power-law relationship between storage and runoff (Q = kS(n)), and incorporating a delay parameter, were created. The parameters k, n and delay were optimized to best fit each of the runoff responses individually. The range and pattern of optimized parameter values was analysed with respect to roof and event configuration. An analysis was performed to determine the sensitivity of the shape of the runoff profile to changes in parameter values. There appears to be potential to consolidate values of n by roof slope and drainage component material.

  10. The Energy Impact in Buildings of Vegetative Solutions for Extensive Green Roofs in Temperate Climates

    Directory of Open Access Journals (Sweden)

    Benedetta Barozzi

    2016-08-01

    Full Text Available Many bibliographical studies have highlighted the positive effects of green roofs as technological solutions both for new and renovated buildings. The one-year experimental monitoring campaign conducted has investigated, in detail, some aspects related to the surface temperature variation induced by the presence of different types of vegetation compared to traditional finishing systems for flat roofs and their impact from an energy and environmental point of view. The results obtained underlined how an appropriate vegetative solution selection can contribute to a significant reduction of the external surface temperatures (10 °C–20 °C for I > 500 W/m2 and 0 °C–5 °C for I < 500 W/m2, regardless of the season compared to traditional flat roofs. During the winter season, the thermal gradients of the planted surface temperatures are close to zero compared to the floor, except under special improving conditions. This entails a significant reduction of the energy loads from summer air conditioning, and an almost conservative behavior with respect to that from winter heating consumption. The analysis of the inside growing medium temperatures returned a further interesting datum, too: the temperature gradient with respect to surface temperature (annual average 4 °C–9 °C is a function of solar radiation and involves the insulating contribution of the soil.

  11. Linking evapotranspiration to stormwater reduction and attenuation in green roofs in Calgary, Alberta

    Science.gov (United States)

    Breach, P. A.; Robinson, C. E.; Voogt, J. A.; Smart, C. C.; O'Carroll, D. M.

    2013-12-01

    Green roofs have been used for centuries to insulate buildings and beautify urban environments. European countries, especially Germany, have adopted green roofs use in modern buildings, helping raise awareness of their many potential benefits. Green roofs have been shown to: effectively reduce and filter stormwater thereby decreasing the burden on urban sewer systems; provide insulation and lower roof surface temperature leading to a decrease in building energy load and reduced sensible heat flux to the urban atmosphere; and to extend the life of a roof by decreasing the temperature fluctuations which cause roof damage. Given that green buildings can mitigate against the negative impacts of storm water runoff and reduce the heating and cooling demands, use of green roofs in Canada might prove extremely beneficial due to our intense climate. However, the implementation of green roofs in North American urban environments remains underused, in part due to a lack of climate appropriate green roof design guidelines that are supported by scientific understanding of their performance in North American climates. The capacity of a green roof installation to moderate runoff depends on the storage capacity of the rooting medium at the start of the rainfall event which in turn is constrained by roof loading. The influence of medium depth is investigated through comparison to 15 cm and 10cm deep planting modules. Storage capacity has a finite limit, making rapid drainage and evapotranspiration loss essential to restore the retardation of a subsequent storm. Sustaining live plant cover requires avoidance of saturated conditions and retention of minimum soil moisture levels. These limits constrain the design options with distinctive climatic stresses. Here the performance of experimental green roof modules is investigated under particularly high climatic stressing at Calgary Alberta Canada. 10 cm modules show rapid drying to unacceptably low residual moisture content, whereas 15

  12. Development of a green roof environmental monitoring and meteorological network in new york city.

    Science.gov (United States)

    Gaffin, Stuart R; Khanbilvardi, Reza; Rosenzweig, Cynthia

    2009-01-01

    Green roofs (with plant cover) are gaining attention in the United States as a versatile new environmental mitigation technology. Interest in data on the environmental performance of these systems is growing, particularly with respect to urban heat island mitigation and stormwater runoff control. We are deploying research stations on a diverse array of green roofs within the New York City area, affording a new opportunity to monitor urban environmental conditions at small scales. We show some green roof systems being monitored, describe the sensor selection employed to study energy balance, and show samples of selected data. These roofs should be superior to other urban rooftops as sites for meteorological stations.

  13. Development of a Green Roof Environmental Monitoring and Meteorological Network in New York City

    Directory of Open Access Journals (Sweden)

    Cynthia Rosenzweig

    2009-04-01

    Full Text Available Green roofs (with plant cover are gaining attention in the United States as a versatile new environmental mitigation technology. Interest in data on the environmental performance of these systems is growing, particularly with respect to urban heat island mitigation and stormwater runoff control. We are deploying research stations on a diverse array of green roofs within the New York City area, affording a new opportunity to monitor urban environmental conditions at small scales. We show some green roof systems being monitored, describe the sensor selection employed to study energy balance, and show samples of selected data. These roofs should be superior to other urban rooftops as sites for meteorological stations.

  14. Mainstreaming green roofs in urban regeneration, Birmingham, UK

    Energy Technology Data Exchange (ETDEWEB)

    Coyne, R. [Groundwork Birmingham and Solihull, Handsworth, Birmingham (United Kingdom)

    2006-07-01

    Historically, Birmingham, United Kingdom was an industrial metal finishing and car production centre. The city centre was redeveloped in the 1960s and 1970s. The new infrastructure was car-dominated with an elevated urban motorway, which forced pedestrians underground. In the 1980s, due to failing industry, rising unemployment and the negative image created by the concrete infrastructure, the city went into decline. In response, the city developed a strong redevelopment vision. This included policies such as removing the concrete collar, greatly expanding the city centre core and rebranding as a service sector centre. However, it was also determined that in addition to these policy transformations, increasing knowledge about the impact of development on the environment was also needed. The value of environmental protection and brownfield regeneration was emphasized. It was determined that green roofs would be able to provide benefits across a range of social and environmental issues including air quality, sustainable urban drainage, visual amenity and biodiversity. As such, a large grant to install the first green roofs in Birmingham city centre on 4 buildings was sought. The grant will be used for research on biodiversity, energy and water management and to demonstrate benefits to developers and decision makers. The main planning driver is mitigation for destruction of black redstart sites as brownfield sites are redeveloped. Simultaneously, measurable targets will be established for Birmingham City Council to adopt in order to deliver sustainable development.

  15. Contribution of green roofs and walls to ecosystem services of urban green

    NARCIS (Netherlands)

    Hop, M.E.C.M.; Hiemstra, J.A.

    2012-01-01

    This paper reports a literature review of the large-scale ecosystem services (ESS) which green roofs and walls can provide for cities. A short overview of 17 ESS’s is given. Much research has been done on ESS’s meeting immediate physical human needs and providing long-term physical and socioeconomic

  16. Contribution of green roofs and walls to ecosystem services of urban green

    NARCIS (Netherlands)

    Hop, M.E.C.M.; Hiemstra, J.A.

    2012-01-01

    This paper reports a literature review of the large-scale ecosystem services (ESS) which green roofs and walls can provide for cities. A short overview of 17 ESS’s is given. Much research has been done on ESS’s meeting immediate physical human needs and providing long-term physical and socioeconomic

  17. Determining Thermal Specifications for Vegetated GREEN Roofs in Moderate Winter Climats

    NARCIS (Netherlands)

    Ravesloot, Christoph Maria

    2015-01-01

    Because local weather conditions in moderate climates are changing constantly, heat transfer specifications of substrate and vegetation in vegetated green roofs also change accordingly. Nevertheless, it is assumed that vegetated green roofs can have a positive effect on the thermal performance of co

  18. An Insight into the Commercial Viability of Green Roofs in Australia

    Directory of Open Access Journals (Sweden)

    Nicole Tassicker

    2016-06-01

    Full Text Available Construction industries around the world have, in recent history, become increasingly concerned with the sustainability of building practices. Inherently, the development of the built environment results in partial or complete destruction of the natural environment. Advanced European and North American countries have turned to green roofs as a means of sustainable development. Australia, on the other hand, has yet to fully realize the potential of green roof technology. In the first case, an extensive review of green roof literature was undertaken to establish the dominant perspectives and over-riding themes within the established body of international literature. The collection of primary data took the form of qualitative, semi-structured interviews with a range of construction practitioners and green roof experts; landscape architects, consultants and academics. The information gained from the interviews facilitated the primary aim of the paper; to critically analyse the state-of-practice in the Australian green roof industry. Green roofs, despite their proven sustainability benefits and their international success, have experienced a relatively sluggish uptake in the Australian construction industry. With this being said, the Australian green roof industry is considered to have promising potential for the future; should there be legislative changes made in its favour or greater education within the industry. To advance the local industry, it was found that government authorities are required to adapt policy settings to better encourage the use of green roofs, whilst industry bodies are required to host better, more targeted educational programs.

  19. Extensive Green Roof Species and Soilless Media Evaluations in Semi-arid Colorado

    Science.gov (United States)

    In the high elevation, semi-arid climate of Colorado, green roofs have not been scientifically tested. This research examined alternative plant species, soilless media blends and plant interactions on an existing, modular-extensive (shallow, 10 cm deep) green roof in Denver, Colo...

  20. Eco-Environmental Factors in Green Roof Application in Indian Cities

    Science.gov (United States)

    Mukherjee, M.

    2014-09-01

    Green-roof is the cost-effective environmental mitigation strategy for urban areas [1]. Its application is limited in India primarily due to inadequate understanding about its cost-benefit analysis and technicalities of its maintenance. Increasing awareness about green roof can alter conservative attitude towards its application. So, this work presents a quantified study on green-roof types, cost and environmental benefits while considering different geo-urban climate scenarios for cities of Kolkata, Mumbai, Chennai and New Delhi. Cost estimation for extensive and intensive green-roof with reference to commonly used roof in urban India is also worked out. Attributes considered for environmental discussion are energy savings related to thermal heat gain through roof, roof-top storm-water drainage and sound attenuation. The comparative study confirms that further focused study on individual cities would identify city-specific objectives for green-roof application; strategies like awareness, capacity building programmes, incentives, demonstration projects etc. can be worked out accordingly for wider application of green-roof in Indian cities.

  1. Hot trends in design : chic sustainability, unique driving factors and boutique green roofs

    Energy Technology Data Exchange (ETDEWEB)

    Velazquez, L.S. [American Society of Landscape Architects, Washington, DC (United States)]|[Greenroofs.com, Alpharetta, GA (United States); Kiers, K. [Greenroofs.com, Alpharetta, GA (United States)

    2007-07-01

    Green roofs are well known for their ecological benefits but less for their architectural usage. Green roofs offer more to the urban landscape than simply ecological, economic and aesthetic attributes of storm water management, temperature and energy reduction, and provision of additional green space. This paper focused on the top ten architectural trends in vegetated rooftop design. It addressed issues regarding client demands for green roofs and questioned if green roofs should be defined solely by their function as an ecological cover. The top ten trends revealed out-of-the ordinary applications, specialty designs and unusual projects on the boards. The paper looked beyond storm water and heat islands, and explored plans for innovative recreation, including a rooftop ski slope in Delft, the Netherlands, and a converted helipad turned into temporary grass tennis court in Dubai. The paper also presented less typical green roof market drivers, such as a doggie green space for a 10-year old, 9-pound Yorkie and a rooftop garden with plants from the Bible as a teaching laboratory for ministers. Other proposed projects that were discussed included plans for rice paddies on rooftop farms in China and the Vancouver Olympic Village with 50 per cent green roof coverage. The top ten list was organized under the following topics: boutique green roofs; sports and recreation; living roofs and living walls; eco resorts, hotels and therapeutic gardens; food on the roof; cutting edge applications; government and big box applications, cool green residences; mega green roofs; and, visionary proposed projects. 77 refs., 77 figs.

  2. Use of green roofs for ultra-urban stream restoration in the Georgia Piedmont, USA

    Energy Technology Data Exchange (ETDEWEB)

    Carter, T. [Georgia Univ., Athens, GA (United States). Inst. of Technology; Rasmussen, T.C. [Georgia Univ., Athens, GA (United States). Warnell School of Forest Resources

    2005-07-01

    As a result of clean water acts in the United States, stormwater permits are required for local governments that are designed to reduce impacts on receiving water bodies. Elevated runoff volumes and rates lead to high pollutant transfer and altered hydrology. Best management practices (BMP) for stormwater include porous pavements, bioretention ponds and vegetated swales. Green roofs have been overlooked as a tool for managing stormwater. This study tested vegetated roof plots at the University of Georgia for their effectiveness in reducing stormwater flows. Two test sites were retrofitted onto an existing flat roof at a site on the university campus. A control plot was used to validate the green roof performance. Storm events were continuously monitored for a 1 year period. Flow was calculated based on the width of the orifice and the height of the water. Detailed spatial analysis was then performed in an urban watershed to determine the effect of widespread green roof implementation using a soil conservation service curve number model. Green roof curve numbers were found for 11 storm events. Composite curve numbers were established for different scenarios to model changes in stormwater volume for existing land cover, the greening of all roofs, and the greening of all flat roofs. Results showed that green roof stormwater retention ranged from 39 to 100 per cent. It was concluded that green roofs alone cannot solely be relied on to provide the minimum recommended stormwater management at the watershed scale. Green roofs must be used with other management strategies in a comprehensive watershed management plan if effective rehabilitation is to be considered. 14 refs., 2 tabs., 5 figs.

  3. The influence of dual-substrate-layer extensive green roofs on rainwater runoff quantity and quality.

    Science.gov (United States)

    Wang, Xiaoou; Tian, Yimei; Zhao, Xinhua

    2017-08-15

    This study investigates the ability of dual-substrate-layer extensive green roofs to retain rainwater and reduce pollutant leaching. The substrates in dual-substrate-layer green roofs consist of an upper organic nutrition layer for plant growth and a lower inorganic adsorption layer for water retention and pollutant reduction. One traditional single-substrate-layer extensive green roof was built for comparison with dual-substrate-layer green roofs. During the experimental period, dual-substrate-layer green roofs supported better natural vegetation growth, with coverage exceeding 90%, while the coverage in single-substrate-layer green roof was over 80%. Based on the average retention value of the total rainfall for four types of simulated rains (the total rainfall depth (mm) was 43.2, 54.6, 76.2 and 86.4, respectively), the dual-substrate-layer green roofs, which used the mixture of activated charcoal with perlite and vermiculite as the adsorption substrate, possessed better rainfall retention performance (65.9% and 55.4%) than the single-substrate-layer green roof (52.5%). All of the dual-substrate-layer green roofs appeared to be sinks for organics, heavy metals and all forms of nitrogen in all cases, while acted as sources of phosphorus contaminants in the case of heavy rains. In consideration of the factors of water retention, pollution reduction and service life of the green roof, a mixture of activated charcoal and/or pumice with perlite and vermiculite is recommended as the adsorption substrate. The green roofs were able to mitigate mild acid rain, raising the pH from approximately 5.6 in rainfall to 6.5-7.6 in green roof runoff. No signs of a first flush effect for phosphate, total phosphorus, ammonia nitrogen, nitrate nitrogen, total nitrogen, organics, zinc, lead, chromium, manganese, copper, pH or turbidity were found in the green roof runoff. Cost analysis further proved the practicability of dual-substrate-layer green roofs in retaining rainwater, and

  4. Establishment and performance of an experimental green roof under extreme climatic conditions

    Energy Technology Data Exchange (ETDEWEB)

    Klein, Petra M., E-mail: pkklein@ou.edu [School of Meteorology, University of Oklahoma, Norman, OK (United States); Coffman, Reid, E-mail: rcoffma4@kent.edu [College of Architecture and Environmental Design, Kent State University, Kent, OH (United States)

    2015-04-15

    Green roofs alter the surface energy balance and can help in mitigating urban heat islands. However, the cooling of green roofs due to evapotranspiration strongly depends on the climatic conditions, and vegetation type and density. In the Southern Central Plains of the United States, extreme weather events, such as high winds, heat waves and drought conditions pose challenges for successful implementation of green roofs, and likely alter their standard performance. The National Weather Center Experimental Green Roof, an interdisciplinary research site established in 2010 in Norman, OK, aimed to investigate the ecological performance and surface energy balance of green roof systems. Starting in May 2010, 26 months of vegetation studies were conducted and the radiation balance, air temperature, relative humidity, and buoyancy fluxes were monitored at two meteorological stations during April–October 2011. The establishment of a vegetative community trended towards prairie plant dominance. High mortality of succulents and low germination of grasses and herbaceous plants contributed to low vegetative coverage. In this condition succulent diversity declined. Bouteloua gracilis and Delosperma cooperi showed typological dominance in harsh climatic conditions, while Sedum species experienced high mortality. The plant community diversified through volunteers such as Euphorbia maculate and Portulaca maculate. Net radiation measured at a green-roof meteorological station was higher than at a control station over the original, light-colored roofing material. These findings indicate that the albedo of the green roof was lower than the albedo of the original roofing material. The low vegetative coverage during the heat and drought conditions in 2011, which resulted in the dark substrate used in the green roof containers being exposed, likely contributed to the low albedo values. Nevertheless, air temperatures and buoyancy fluxes were often lower over the green roof indicating

  5. Storm water infiltration in a monitored green roof for hydrologic restoration.

    Science.gov (United States)

    Palla, A; Sansalone, J J; Gnecco, I; Lanza, L G

    2011-01-01

    The objectives of this study are to provide detailed information about green roof performance in the Mediterranean climate (retained volume, peak flow reduction, runoff delay) and to identify a suitable modelling approach for describing the associated hydrologic response. Data collected during a 13-month monitoring campaign and a seasonal monitoring campaign (September-December 2008) at the green roof experimental site of the University of Genova (Italy) are presented together with results obtained in quantifying the green roof hydrologic performance. In order to examine the green roof hydrologic response, the SWMS_2D model, that solves the Richards' equation for two-dimensional saturated-unsaturated water flow, has been implemented. Modelling results confirm the suitability of the SWMS_2D model to properly describe the hydrologic response of the green roofs. The model adequately reproduces the hydrographs; furthermore, the predicted soil water content profile generally matches the observed values along a vertical profile where measurements are available.

  6. A Mass Balance Model for Designing Green Roof Systems that Incorporate a Cistern for Re-Use

    OpenAIRE

    Manoj Chopra; Martin Wanielista; Mike Hardin

    2012-01-01

    Green roofs, which have been used for several decades in many parts of the world, offer a unique and sustainable approach to stormwater management. Within this paper, evidence is presented on water retention for an irrigated green roof system. The presented green roof design results in a water retention volume on site. A first principle mass balance computer model is introduced to assist with the design of these green roof systems which incorporate a cistern to capture and reuse runoff waters...

  7. Habitat connectivity and local conditions shape taxonomic and functional diversity of arthropods on green roofs.

    Science.gov (United States)

    Braaker, Sonja; Obrist, Martin Karl; Ghazoul, Jaboury; Moretti, Marco

    2017-02-06

    Increasing development of urban environments creates high pressure on green spaces with potential negative impacts on biodiversity and ecosystem services. There is growing evidence that green roofs - rooftops covered with vegetation - can contribute mitigate the loss of urban green spaces by providing new habitats for numerous arthropod species. Whether green roofs can contribute to enhance taxonomic and functional diversity and increase connectivity across urbanized areas remains, however, largely unknown. Furthermore, only limited information is available on how environmental conditions shape green roof arthropod communities. We investigated the community composition of arthropods (Apidae, Curculionidae, Araneae and Carabidae) on 40 green roofs and 40 green sites at ground level in the city of Zurich, Switzerland. We assessed how the site's environmental variables (such as area, height, vegetation, substrate and connectivity among sites) affect species richness and functional diversity using generalized linear models. We used an extension of co-inertia analysis (RLQ) and fourth-corner analysis to highlight the mechanism underlying community assemblages across taxonomic groups on green roof and ground communities. Species richness was higher at ground-level sites, while no difference in functional diversity was found between green roofs and ground sites. Green roof arthropod diversity increased with higher connectivity and plant species richness, irrespective of substrate depth, height and area of green roofs. The species trait analysis reviewed the mechanisms related to the environmental predictors that shape the species assemblages of the different taxa at ground and roof sites. Our study shows the important contribution of green roofs in maintaining high functional diversity of arthropod communities across different taxonomic groups, despite their lower species richness compared with ground sites. Species communities on green roofs revealed to be characterized

  8. Dynamic Simulation of the Green Roofs Impact on Building Energy Performance, Case Study of Antananarivo, Madagascar

    Directory of Open Access Journals (Sweden)

    Hery Tiana Rakotondramiarana

    2015-05-01

    Full Text Available Green roofs improve building energy performance and constitute an alternative to sustainable buildings. A green roof model is dynamically coupled with a building thermal model to assess its energy performance that takes into account the indoor air temperature dynamic changes. Under the climate conditions in Antananarivo, we compared green and conventional roofs. The present study shows that green roofs protect the roof structure under extreme temperature and large temperature fluctuations. For the case of Antananarivo, the amplitude of the temperature fluctuations at the top face of the support is reduced by 28 °C when using green roof. The impact of the green roof on indoor air temperature and energy demand is investigated. The vegetation decreases the maximum indoor air temperature and improves the building thermal comfort during summer days. It has no effect on the minimum indoor air temperature, but additional soil thickness can increase it. In addition, a global sensitivity analysis, which is carried out on the proposed model without considering any specific weather data, allows us to identify the most influential parameters on the energy demand. It has been found that green roofs have almost insignificant thermal impact in insulated buildings; however, their potential prevails over the building envelope and weather characteristics in the case of non-insulated building.

  9. Quantitative analysis on the urban flood mitigation effect by the extensive green roof system.

    Science.gov (United States)

    Lee, J Y; Moon, H J; Kim, T I; Kim, H W; Han, M Y

    2013-10-01

    Extensive green-roof systems are expected to have a synergetic effect in mitigating urban runoff, decreasing temperature and supplying water to a building. Mitigation of runoff through rainwater retention requires the effective design of a green-roof catchment. This study identified how to improve building runoff mitigation through quantitative analysis of an extensive green-roof system. Quantitative analysis of green-roof runoff characteristics indicated that the extensive green roof has a high water-retaining capacity response to rainfall of less than 20 mm/h. As the rainfall intensity increased, the water-retaining capacity decreased. The catchment efficiency of an extensive green roof ranged from 0.44 to 0.52, indicating reduced runoff comparing with efficiency of 0.9 for a concrete roof. Therefore, extensive green roofs are an effective storm water best-management practice and the proposed parameters can be applied to an algorithm for rainwater-harvesting tank design. © 2013 Elsevier Ltd. All rights reserved.

  10. [Influence of green roof application on water quantity and quality in urban region].

    Science.gov (United States)

    Wang, Shu-Min; Li, Xing-Yang; Zhang, Jun-Hua; Yu, Hui; Hao, You-Zhi; Yang, Wan-Yi

    2014-07-01

    Green roof is widely used in advanced stormwater management as a major measure now. Taking Huxi catchment in Chongqing University as the study area, the relationships between green roof installation with runoff volume and water quality in urban region were investigated. The results showed that roof greening in the urban region contributed to reducing the runoff volume and pollution load. In addition, the spatial distribution and area of green roof also had effects on the runoff water quality. With the conditions that the roof area was 25% of the total watershed area, rainfall duration was 15 min and rainfall intensity was 14.8 mm x h(-1), the peak runoff and total runoff volume were reduced by 5.3% and 31%, the pollution loads of total suspended solid (TSS), total phosphorus (TP) and total nitrogen (TN) decreased by 40.0%, 31.6% and 29.8%, their peak concentrations decreased by 21.0%, 16.0% and -12.2%, and the EMCs (event mean concentrations) were cut down by 13.1%, 0.9% and -1.7%, respectively, when all impervious roofs were greened in the research area. With the increase of roof greening rate, the reduction rates of TSS and TP concentrations increased, while the reduction rate of TN concentration decreased on the whole. Much more improvement could be obtained with the use of green roofs near the outlet of the watershed.

  11. A parametric study of the thermal performance of green roofs in different climates through energy modeling

    Science.gov (United States)

    Mukherjee, Sananda

    In recent years, there has been great interest in the potential of green roofs as an alternative roofing option to reduce the energy consumed by individual buildings as well as mitigate large scale urban environmental problems such as the heat island effect. There is a widespread recognition and a growing literature of measured data that suggest green roofs can reduce building energy consumption. This thesis investigates the potential of green roofs in reducing the building energy loads and focuses on how the different parameters of a green roof assembly affect the thermal performance of a building. A green roof assembly is modeled in Design Builder- a 3D graphical design modeling and energy use simulation program (interface) that uses the EnergyPlus simulation engine, and the simulated data set thus obtained is compared to field experiment data to validate the roof assembly model on the basis of how accurately it simulates the behavior of a green roof. Then the software is used to evaluate the thermal performance of several green roof assemblies under three different climate types, looking at the whole building energy consumption. For the purpose of this parametric simulation study, a prototypical single story small office building is considered and one parameter of the green roof is altered for each simulation run in order to understand its effect on building's energy loads. These parameters include different insulation thicknesses, leaf area indices (LAI) and growing medium or soil depth, each of which are tested under the three different climate types. The energy use intensities (EUIs), the peak and annual heating and cooling loads resulting from the use of these green roof assemblies are compared with each other and to a cool roof base case to determine the energy load reductions, if any. The heat flux through the roof is also evaluated and compared. The simulation results are then organized and finally presented as a decision support tool that would

  12. Numerical simulation of greening effects for idealised roofs with regional climate forcing

    Energy Technology Data Exchange (ETDEWEB)

    Gross, Guenter [Hannover Univ. (Germany). Inst. fuer Meteorologie und Klimatologie

    2012-04-15

    A numerical model was used to simulate temperature distribution in and above an extensive green roof with a long term forcing adopted from a regional climate model. Time variations of temperature for different time scales ranging from days to decades have been calculated. The results are in good agreement with selected field experiments and generally reinforce the understanding prevailing in literature regarding temperature differences of green roofs compared to a concrete roof. Green roofs result in a significant reduction of daytime human heat load and an improvement of thermal comfort conditions, while during night-time a concrete roof favours low temperatures and a low number of minimum temperatures above 20 C (tropical nights). A future shift in seasonal precipitation would necessitate irrigation in the summer months to ensure the vitality of roof vegetation. An estimation of the amount of additional watering and the increased number of watering days per year is given. (orig.)

  13. Spatial environmental heterogeneity affects plant growth and thermal performance on a green roof

    Energy Technology Data Exchange (ETDEWEB)

    Buckland-Nicks, Michael; Heim, Amy; Lundholm, Jeremy, E-mail: jlundholm@smu.ca

    2016-05-15

    Green roofs provide ecosystem services, including stormwater retention and reductions in heat transfer through the roof. Microclimates, as well as designed features of green roofs, such as substrate and vegetation, affect the magnitude of these services. Many green roofs are partially shaded by surrounding buildings, but the effects of this within-roof spatial environmental heterogeneity on thermal performance and other ecosystem services have not been examined. We quantified the effects of spatial heterogeneity in solar radiation, substrate depth and other variables affected by these drivers on vegetation and ecosystem services in an extensive green roof. Spatial heterogeneity in substrate depth and insolation were correlated with differential growth, survival and flowering in two focal plant species. These effects were likely driven by the resulting spatial heterogeneity in substrate temperature and moisture content. Thermal performance (indicated by heat flux and substrate temperature) was influenced by spatial heterogeneity in vegetation cover and substrate depth. Areas with less insolation were cooler in summer and had greater substrate moisture, leading to more favorable conditions for plant growth and survival. Spatial variation in substrate moisture (7%–26% volumetric moisture content) and temperature (21 °C–36 °C) during hot sunny conditions in summer could cause large differences in stormwater retention and heat flux within a single green roof. Shaded areas promote smaller heat fluxes through the roof, leading to energy savings, but lower evapotranspiration in these areas should reduce stormwater retention capacity. Spatial heterogeneity can thus result in trade-offs between different ecosystem services. The effects of these spatial heterogeneities are likely widespread in green roofs. Structures that provide shelter from sun and wind may be productively utilized to design higher functioning green roofs and increase biodiversity by providing habitat

  14. Assessing the Performance of Large Scale Green Roofs and Their Impact on the Urban Microclimate

    Science.gov (United States)

    Smalls-Mantey, L.; Foti, R.; Montalto, F. A.

    2015-12-01

    In ultra-urban environments green roofs offer a feasible solution to add green infrastructure (GI) in neighborhoods where space is limited. Green roofs offer the typical advantages of urban GI such as stormwater reduction and management while providing direct benefits to the buildings on which they are installed through thermal protection and mitigation of temperature fluctuations. At 6.8 acres, the Jacob K. Javits Convention Center (JJCC) in New York City, hosts the second largest green roof in the United States. Since its installation in August 2013, the Sustainable Water Resource (SWRE) Laboratory at Drexel University has monitored the climate on and around the green roof by means of four weather stations situated on various roof and ground locations. Using two years of fine scale climatic data collected at the JJCC, this study explores the energy balance of a large scale green roof system. Temperature, radiation, evapotranspiration and wind profiles pre- and post- installation of the JJCC green roof were analyzed and compared across monitored locations, with the goal of identifying the impact of the green roof on the building and urban micro-climate. Our findings indicate that the presence of the green roof, not only altered the climatic conditions above the JJCC, but also had a measurable impact on the climatic profile of the areas immediately surrounding it. Furthermore, as a result of the mitigation of roof temperature fluctuations and of the cooling provided during warmer months, an improvement of the building thermal efficiency was contextually observed. Such findings support the installation of GI as an effective practice in urban settings and important in the discussion of key issues including energy conservation measures, carbon emission reductions and the mitigation of urban heat islands.

  15. Two-dimensional modeling of water and heat fluxes in green roof substrates

    Science.gov (United States)

    Suarez, F. I.; Sandoval, V. P.

    2016-12-01

    Due to public concern towards sustainable development, greenhouse gas emissions and energy efficiency, green roofs have become popular in the last years. Green roofs integrate vegetation into infrastructures to reach additional benefits that minimize negative impacts of the urbanization. A properly designed green roof can reduce environmental pollution, noise levels, energetic requirements or surface runoff. The correct performance of green roofs depends on site-specific conditions and on each component of the roof. The substrate and the vegetation layers strongly influence water and heat fluxes on a green roof. The substrate is an artificial media that has an improved performance compared to natural soils as it provides critical resources for vegetation survival: water, nutrients, and a growing media. Hence, it is important to study the effects of substrate properties on green roof performance. The objective of this work is to investigate how the thermal and hydraulic properties affect the behavior of a green roof through numerical modeling. The substrates that were investigated are composed by: crushed bricks and organic soil (S1); peat with perlite (S2); crushed bricks (S3); mineral soil with tree leaves (S4); and a mixture of topsoil and mineral soil (S5). The numerical model utilizes summer-arid meteorological information to evaluate the performance of each substrate. Results show that the area below the water retention curve helps to define the substrate that retains more water. In addition, the non-linearity of the water retention curve can increment the water needed to irrigate the roof. The heat propagation through the roof depends strongly on the hydraulic behavior, meaning that a combination of a substrate with low thermal conductivity and more porosity can reduce the heat fluxes across the roof. Therefore, it can minimize the energy consumed of an air-conditioner system.

  16. System for monitoring of green roof performance: use of weighing roof segment and non-invasive visualization

    Science.gov (United States)

    Jelinkova, Vladmira; Dohnal, Michal; Picek, Tomas; Sacha, Jan

    2015-04-01

    Understanding the performance of technogenic substrates for green roofs is a significant task in the framework of sustainable urban planning and water/energy management. The potential retention and detention of the anthropogenic, light weight soil systems and their temporal soil structure changes are of major importance. A green roof test segment was built to investigate the benefits of such anthropogenic systems. Adaptable low-cost system allows long-term monitoring of preferred characteristics. Temperature and water balance measurements complemented with meteorological observations and knowledge of physical properties of the substrates provide basis for detailed analysis of thermal and hydrological regime in green roof systems. The first results confirmed the benefits of green roof systems. The reduction of temperature fluctuations as well as rainfall runoff was significant. Depending on numerous factors such substrate material or vegetation cover the test green roof suppressed the roof temperature amplitude for the period analyzed. The ability to completely prevent (light rainfall events) or reduce and delay (medium and heavy rainfall events) the peak runoff was also analyzed. Special attention is being paid to the assessment of soil structural properties related to possible aggregation/disaggregation, root growth, weather conditions and associated structural changes using non-invasive imaging method. X-ray computed microtomography of undisturbed soil samples (taken from experimental segments) is used for description of pore space geometry, evaluation of surface to volume ratio, additionally for description of cracks and macropores as a product of soil flora and fauna activity. The information from computed tomography imaging will be used for numerical modeling of water flow in variable saturated porous media. The research was realized as a part of the University Centre for Energy Efficient Buildings supported by the EU and with financial support from the Czech

  17. Improving green roofs and rail road greening systems using Bacillus subtilis and Lactobacillus ssp.

    Science.gov (United States)

    Grüneberg, H; Oschmann, C; Dunya, S; Ulrichs, C

    2006-01-01

    Aim of the present study was the improvement of existing methods for green roof and rail road greening systems using soil borne bacteria. Bacillus subtilis and Lactobacillus ssp. alone and in combination with vinasse applied to different growing substrates were tested. The substrates were brick chips, textile mats, mineral wool mats, and a commercial available substrate for the Swedish company VegTech. All four substrates were tested along an artificial rail track on the experimental station at Humboldt University Berlin, and partly on an existing rail track in Munich, Germany. Plants selected for the experiments belong to the genus Sedum, which is relatively tolerant to dry conditions. Inoculation of plants with bacteria had no effect on plant growth parameters and on coverage of different mobile bedding systems with Sedum plants. There was no significant difference between the various treatments in Munich. In both experiments, the addition of vinasse alone improved plant growth. Plant growth was significantly different on all substrates, whereas brick chips and the commercial roof soil was the best substrate. Brick chips are a cheap substrate which can be used for rail track greening. The results indicate that the quality of the substrate is the most important factor for remediation and greening of rail tracks and roof tops. The rapid growth of plants can be influenced by the application of vinasse as additional nutrient solution (potash (K) source) or nutrient enriched substrate.

  18. Development and integration of a green roof model within whole building energy simulation

    OpenAIRE

    Decruz, Aloysius

    2016-01-01

    Green roofs are increasingly being employed as a sustainability feature of buildings. The sustainability approach in building designs requires reducing energy consumption and adopting low carbon energy sources without compromising the increasing expectations of comfort and health levels. Given the wide range of building designs, climates and green roof types, it is desirable to evaluate at the design stage the energy saving impact and other potential benefits from the application of green roo...

  19. Green living roof implementation and influences of the soil layer on its properties

    Directory of Open Access Journals (Sweden)

    Dimitrijević Dragana G.

    2016-01-01

    Full Text Available Affected by undeniable climatic change, the temperature of the urban areas rises continually, increasing rapidly the energy problem of cities and amplifying the pollution problems. The thermal stress is increased, thus both the indoor and the outdoor thermal comfort levels are decreased, enhancing the health problems. Green roof implementation in the building envelope is strategy that provides heat island amelioration, thermal comfort for occupants and reduces energy consumption of buildings. Green living roofs are a passive cooling technique, which can stop the incoming solar radiation from reaching the building structure below. In this paper, we assessed the importance of the green roofs in providing environmental and building energy benefits, and brief investigation on the different configuration of the soil layer in the green roof assembly influences to the temperature of the roof surface was presented. Investigation was conducted for first phase of the living roof growth. Four cells were designed in SolidWorks software where the transient thermal study was performed in order to determine differences between the behavior of the conventional roof and three green roof types.

  20. Temperature decreases in an urban canyon due to green walls and green roofs in diverse climates

    Energy Technology Data Exchange (ETDEWEB)

    Jones, Phil [Cardiff University (United Kingdom). Welsh School of Architecture; Alexandri, Eleftheria

    2008-04-15

    This paper discusses the thermal effect of covering the building envelope with vegetation on the microclimate in the built environment, for various climates and urban canyon geometries. A two-dimensional, prognostic, micro scale model has been used, developed for the purposes of this study. The climatic characteristics of nine cities, three urban canyon geometries, two canyon orientations and two wind directions are examined. The thermal effect of green roofs and green walls on the built environment is examined in both inside the canyon and at roof level. The effects of this temperature decrease on outdoors thermal comfort and energy savings are examined. Conclusions are drawn on whether plants on the building envelope can be used to tackle the heat island effect, depending on all these parameters taken into consideration. (author)

  1. Assessment of the hydrological impacts of green roof: From building scale to basin scale

    Science.gov (United States)

    Versini, P.-A.; Ramier, D.; Berthier, E.; de Gouvello, B.

    2015-05-01

    At the building scale, the use of green roof has shown a positive impact on urban runoff (decrease and slow-down in peak discharge, decrease in runoff volume). The present work aims to study whether similar effects are possible at the basin scale and what is the minimum spreading of green runoff needed to observe significant impacts. It is particularly focused on the circumstances of such impacts and how they can contribute to storm water management in urban environment. Based on observations on experimental green roofs, a conceptual model has been developed and integrated into the SWMM urban rainfall-runoff model to reproduce the hydrological behaviour of two different types of green roof. It has been combined with a method defining green roofing scenarios by estimating the maximum roof area that can be covered. This methodology has been applied on a long time series (18 years) to the Châtillon urban basin (Haut-de-Seine county, France) frequently affected by urban flooding. For comparison, the same methodology has been applied at the building scale and a complementary analysis has been conducted to study which hydrometeorological variables may affect the magnitude of these hydrological impacts at both scales. The results show green roofs, when they are widely implemented, can affect urban runoff in terms of peak discharge and volume, and avoid flooding in several cases. Both precipitation - generally accumulated during the whole event- and the initial substrate saturation are likely to have an impact on green roof effects. In this context, the studied green roofs seem useful to mitigate the effects of usual rainfall events but turn out being less helpful for the more severe ones. We conclude that, combined with other infrastructures, green roofs represent an interesting contribution to urban water management in the future.

  2. Green-Roof Effects on Neighborhood Microclimate and Human Thermal Sensation

    Directory of Open Access Journals (Sweden)

    C. Y. Jim

    2013-01-01

    Full Text Available Green roofs have been recognized as an effective sustainable design tool to mitigate urban heat island (UHI effects. Previous studies have identified green-roof benefits in cooling and energy-conservation at the building scale, with limited exploration of the wider influence on neighborhood microclimate and human thermal comfort (HTC. This paper investigated the impacts of community-scale green-roof installation on air temperature and HTC in five typical residential neighborhoods of subtropical Hong Kong. The microclimate models ENVI-met and RayMan permitted studies of two main green-roof scenarios, namely extensive (EGR and intensive (IGR. Microclimatic monitoring data from a local experimental green-roof site validated the modeling methods. The results verified that green-roof cooling effects were not restricted to rooftops, but extended to the ground to improve neighborhood microclimate. EGR reduced pedestrian-level air temperature by 0.4–0.7 °C, and IGR by 0.5–1.7 °C, with maximum effect in open-set low rise sites. Coverage by building footprints and building height dampened lateral and vertical advection of cool air generated by green roofs. Roof greening also improved notably the rooftop-podium level HTC. Diurnal duration of high heat stress was reduced by 6–9 h for EGR scenarios, and 9–11 h for IGR. The findings indicated that large-scale green-roof installation could bring neighborhood-wide cooling, mitigate urban heat island effect, and furnish more comfortable thermal environment for urban residents.

  3. Spatial environmental heterogeneity affects plant growth and thermal performance on a green roof.

    Science.gov (United States)

    Buckland-Nicks, Michael; Heim, Amy; Lundholm, Jeremy

    2016-05-15

    Green roofs provide ecosystem services, including stormwater retention and reductions in heat transfer through the roof. Microclimates, as well as designed features of green roofs, such as substrate and vegetation, affect the magnitude of these services. Many green roofs are partially shaded by surrounding buildings, but the effects of this within-roof spatial environmental heterogeneity on thermal performance and other ecosystem services have not been examined. We quantified the effects of spatial heterogeneity in solar radiation, substrate depth and other variables affected by these drivers on vegetation and ecosystem services in an extensive green roof. Spatial heterogeneity in substrate depth and insolation were correlated with differential growth, survival and flowering in two focal plant species. These effects were likely driven by the resulting spatial heterogeneity in substrate temperature and moisture content. Thermal performance (indicated by heat flux and substrate temperature) was influenced by spatial heterogeneity in vegetation cover and substrate depth. Areas with less insolation were cooler in summer and had greater substrate moisture, leading to more favorable conditions for plant growth and survival. Spatial variation in substrate moisture (7%-26% volumetric moisture content) and temperature (21°C-36°C) during hot sunny conditions in summer could cause large differences in stormwater retention and heat flux within a single green roof. Shaded areas promote smaller heat fluxes through the roof, leading to energy savings, but lower evapotranspiration in these areas should reduce stormwater retention capacity. Spatial heterogeneity can thus result in trade-offs between different ecosystem services. The effects of these spatial heterogeneities are likely widespread in green roofs. Structures that provide shelter from sun and wind may be productively utilized to design higher functioning green roofs and increase biodiversity by providing habitat

  4. A simple rainfall-runoff model for the single and long term hydrological performance of green roofs

    DEFF Research Database (Denmark)

    Locatelli, Luca; Mark, Ole; Mikkelsen, Peter Steen

    Green roofs are being widely implemented for storm water control and runoff reduction. There is need for incorporating green roofs into urban drainage models in order to evaluate their impact. These models must have low computational costs and fine time resolution. This paper aims to develop...... a model of green roof hydrological performance. A simple conceptual model for the long term and single event hydrological performance of green roofs, shows to be capable of reproducing observed runoff measurements. The model has surface and subsurface storage components representing the overall retention...... capacity of the green roof. The runoff from the system is described by the non-linear reservoir method and the storage capacity of the green roof is continuously re-established by evapotranspiration. Runoff data from a green roof in Denmark are collected and used for parameter calibration....

  5. Effect of substrate depth and rain-event history on the pollutant abatement of green roofs.

    Science.gov (United States)

    Seidl, Martin; Gromaire, Marie-Christine; Saad, Mohamed; De Gouvello, Bernard

    2013-12-01

    This study compares the effectiveness of two different thickness of green roof substrate with respect to nutrient and heavy metal retention and release. To understand and evaluate the long term behaviour of green roofs, substrate columns with the same structure and composition as the green roofs, were exposed in laboratory to artificial rain. The roofs act as a sink for C, N, P, zinc and copper for small rain events if the previous period was principally dry. Otherwise the roofs may behave as a source of pollutants, principally for carbon and phosphorus. Both field and column studies showed an important retention for Zn and Cu. The column showed, however, lower SS, DOC and metal concentrations in the percolate than could be observed in the field even if corrected for run-off. This is most probably due to the difference in exposition history and weathering processes.

  6. Drought versus heat: What's the major constraint on Mediterranean green roof plants?

    Energy Technology Data Exchange (ETDEWEB)

    Savi, Tadeja, E-mail: tsavi@units.it [Dipartimento di Scienze della Vita, Università di Trieste, Via L. Giorgieri 10, 34127 Trieste (Italy); Dal Borgo, Anna, E-mail: dalborgo.anna@gmail.com [Dipartimento di Scienze della Vita, Università di Trieste, Via L. Giorgieri 10, 34127 Trieste (Italy); Love, Veronica L., E-mail: vllove1@sheffield.ac.uk [Dipartimento di Scienze della Vita, Università di Trieste, Via L. Giorgieri 10, 34127 Trieste (Italy); Department of Landscape, University of Sheffield, Western Bank, Sheffield, South Yorkshire S10 2TN (United Kingdom); Andri, Sergio, E-mail: s.andri@seic.it [Harpo seic verdepensile, Via Torino 34, 34123 Trieste (Italy); Tretiach, Mauro, E-mail: tretiach@units.it [Dipartimento di Scienze della Vita, Università di Trieste, Via L. Giorgieri 10, 34127 Trieste (Italy); Nardini, Andrea, E-mail: nardini@units.it [Dipartimento di Scienze della Vita, Università di Trieste, Via L. Giorgieri 10, 34127 Trieste (Italy)

    2016-10-01

    Green roofs are gaining momentum in the arid and semi-arid regions due to their multiple benefits as compared with conventional roofs. One of the most critical steps in green roof installation is the selection of drought and heat tolerant species that can thrive under extreme microclimate conditions. We monitored the water status, growth and survival of 11 drought-adapted shrub species grown on shallow green roof modules (10 and 13 cm deep substrate) and analyzed traits enabling plants to cope with drought (symplastic and apoplastic resistance) and heat stress (root membrane stability). The physiological traits conferring efficiency/safety to the water transport system under severe drought influenced plant water status and represent good predictors of both plant water use and growth rates over green roofs. Moreover, our data suggest that high substrate temperature represents a stress factor affecting plant survival to a larger extent than drought per se. In fact, the major cause influencing seedling survival on shallow substrates was the species-specific root resistance to heat, a single and easy measurable trait that should be integrated into the methodological framework for screening and selection of suitable shrub species for roof greening in the Mediterranean. - Highlights: • The use of hardy shrub species for roof greening should be increased. • We monitored water status of 11 shrub species growing on shallow green roofs. • Species heat and drought tolerance, growth, and survival were studied. • High substrate temperature significantly affected plant survival. • Root resistance to heat could be used as trait for species selection for green roofs.

  7. The effectiveness of cool and green roofs as urban heat island mitigation strategies

    Science.gov (United States)

    Li, Dan; Bou-Zeid, Elie; Oppenheimer, Michael

    2014-05-01

    Mitigation of the urban heat island (UHI) effect at the city-scale is investigated using the Weather Research and Forecasting (WRF) model in conjunction with the Princeton Urban Canopy Model (PUCM). Specifically, the cooling impacts of green roof and cool (white/high-albedo) roof strategies over the Baltimore-Washington metropolitan area during a heat wave period (7 June-10 June 2008) are assessed using the optimal set-up of WRF-PUCM described in the companion paper by Li and Bou-Zeid (2014). Results indicate that the surface UHI effect (defined based on the urban-rural surface temperature difference) is reduced significantly more than the near-surface UHI effect (defined based on urban-rural 2 m air temperature difference) when these mitigation strategies are adopted. In addition, as the green and cool roof fractions increase, the surface and near-surface UHIs are reduced almost linearly. Green roofs with relatively abundant soil moisture have comparable effect in reducing the surface and near-surface UHIs to cool roofs with an albedo value of 0.7. Significant indirect effects are also observed for both green and cool roof strategies; mainly, the low-level advection of atmospheric moisture from rural areas into urban terrain is enhanced when the fraction of these roofs increases, thus increasing the humidity in urban areas. The additional benefits or penalties associated with modifications of the main physical determinants of green or cool roof performance are also investigated. For green roofs, when the soil moisture is increased by irrigation, additional cooling effect is obtained, especially when the ‘unmanaged’ soil moisture is low. The effects of changing the albedo of cool roofs are also substantial. These results also underline the capabilities of the WRF-PUCM framework to support detailed analysis and diagnosis of the UHI phenomenon, and of its different mitigation strategies.

  8. Water retention and evapotranspiration of green roofs and possible natural vegetation types

    NARCIS (Netherlands)

    Metselaar, K.

    2012-01-01

    Matching vegetation to growing conditions on green roofs is one of the options to increase biodiversity in cities. A hydrological model has been applied to match the hydrological requirements of natural vegetation types to roof substrate parameters and to simulate moisture stress for specific substr

  9. Performance of dryland and wetland plant species on extensive green roofs

    Science.gov (United States)

    MacIvor, J. Scott; Ranalli, Melissa A.; Lundholm, Jeremy T.

    2011-01-01

    Background and Aims Green roofs are constructed ecosystems where plants perform valuable services, ameliorating the urban environment through roof temperature reductions and stormwater interception. Plant species differ in functional characteristics that alter ecosystem properties. Plant performance research on extensive green roofs has so far indicated that species adapted to dry conditions perform optimally. However, in moist, humid climates, species typical of wetter soils might have advantages over dryland species. In this study, survival, growth and the performance of thermal and stormwater capture functions of three pairs of dryland and wetland plant species were quantified using an extensive modular green roof system. Methods Seedlings of all six species were germinated in a greenhouse and planted into green roof modules with 6 cm of growing medium. There were 34 treatments consisting of each species in monoculture and all combinations of wet- and dryland species in a randomized block design. Performance measures were survival, vegetation cover and roof surface temperature recorded for each module over two growing seasons, water loss (an estimate of evapotranspiration) in 2007, and albedo and water capture in 2008. Key Results Over two seasons, dryland plants performed better than wetland plants, and increasing the number of dryland species in mixtures tended to improve functioning, although there was no clear effect of species or habitat group diversity. All species had survival rates >75 % after the first winter; however, dryland species had much greater cover, an important indicator of green roof performance. Sibbaldiopsis tridentata was the top performing species in monoculture, and was included in the best treatments. Conclusions Although dryland species outperformed wetland species, planting extensive green roofs with both groups decreased performance only slightly, while increasing diversity and possibly habitat value. This study provides further

  10. Research on the characteristics of the water quality of rainwater runoff from green roofs.

    Science.gov (United States)

    Gong, Kena; Wu, Qing; Peng, Sen; Zhao, Xinhua; Wang, Xiaochen

    2014-01-01

    This paper investigates the water quality characteristics of rainwater runoff from dual-substrate-layer green roofs in Tianjin, China. The data were collected from four different assemblies and three types of simulated rains. The storm-water runoff quality was monitored from early June through late October 2012 and from July through late November 2013. The results revealed that the runoff water quality would be improved to some extent with the ageing of green roofs and that the quality retention rate better reflected the pollutant retention capacity of the green roof than the pollutant concentration in the runoff water. The investigation clearly demonstrated that green roofs also effectively reduced the chemical oxygen demand and turbidity value and neutralised acid rain to stabilise the pH of the runoff.

  11. Allocation of public and-or private responsibilities. Governance arrangements for green roofs

    NARCIS (Netherlands)

    Mees, H.L.P.

    2012-01-01

    This research was commissioned by Knowledge for Climate, Hotspot Rotterdam Region (http://knowledgeforclimate.climateresearchnetherlands.nl/hotspots/rotterdam-region), and included an international comparison of governance arrangements for the promotion of green roofs as an innovative no-regrets mea

  12. Determining Thermal Specifications for Vegetated GREEN Roofs in Moderate Winter Climats

    OpenAIRE

    Ravesloot, Christoph Maria

    2015-01-01

    Because local weather conditions in moderate climates are changing constantly, heat transfer specifications of substrate and vegetation in vegetated green roofs also change accordingly. Nevertheless, it is assumed that vegetated green roofs can have a positive effect on the thermal performance of construction in winter conditions. Is there proof from scientific research and field testing for this assumption? To answer this question, research is conducted with the main research question: Which...

  13. Carbon Sequestration Potential of Extensive Green Roofs%屋顶绿地碳固定潜力的研究

    Institute of Scientific and Technical Information of China (English)

    陈爱葵; 陆剑; 袁剑刚; 徐亚幸; 杨中艺

    2015-01-01

    屋顶绿化因为能减轻城市内涝、热岛效应和空气污染等一系列城市化带来的负面影响,在很多国家和地区已经得到推广和应用。通过野外调查对10个用草坪草建植的简单式屋顶绿地的碳固定潜力进行评价,并探讨影响其碳固定能力的各种因子。同化箱试验的结果表明,屋顶绿地在白天可以通过吸收和固定 CO2,降低其周围空气中的 CO2含量。在多云清冷的上午,由朝鲜结缕草或狗牙根为主建植而成的屋顶植被在1 h 内吸收的CO2可达0.46 g·m -2,在5 min 内同化箱里 CO2体积分数的降低幅度可达42%(162×10-6);地上部分碳储量试验的结果表明,以草坪草为主建成的屋顶绿地植被的地上部平均固定的有机碳为92.55 g/m2。故屋顶绿地是城市内小型碳库,具有一定的固碳作用。同时,基质厚度与草坪草地上部分的有机碳含量呈显著的正相关,也说明基质厚度可能是影响屋顶绿地碳固定潜力的重要因素。%Green roofs,an increasingly visible component of urban environments,are becoming increas-ingly popular in many countries and have attracted much attention in China.The interest for green roofs has been related to their benefit as the crucial determinants of energy flux and of buildings'water reten-tion,so as to reduce stormwater runoff volumes and peak flows,mitigate effect of urban heat island and also provide urban habitats to improve urban biodiversity.However,there is rare research focusing on its carbon sequestration potential and the mitigation of climate change.In present study,two experiments were conducted on 10 green roofs with the objective of evaluating carbon accumulation potential of green roofs and the factors that affect green roof carbon storage.In the chamber experiment,a green roof was a-ble to absorb CO2 as high as 0.46 g per m2 in one hour,and CO2 concentration declined as much as 162 ×10 -6 over 5 minutes

  14. The hydrological behaviour of extensive and intensive green roofs in a dry climate.

    Science.gov (United States)

    Razzaghmanesh, M; Beecham, S

    2014-11-15

    This paper presents the results of a hydrological investigation of four medium scale green roofs that were set up at the University of South Australia. In this study, the potential of green roofs as a source control device was investigated over a 2 year period using four medium size green roof beds comprised of two growth media types and two media depths. During the term of this study, 226 rainfall events were recorded and these were representative of the Adelaide climate. In general, there were no statistically significant differences between the rainfall and runoff parameters for the intensive and extensive beds except for peak attenuation and peak runoff delay, for which higher values were recorded in the intensive beds. Longer dry periods generally resulted in higher retention coefficients and higher retention was also recorded in warmer seasons. The average retention coefficient for intensive systems (89%) was higher than for extensive systems (74%). It was shown that rainfall depth, intensity, duration and also average dry weather period between events can change the retention performance and runoff volume of the green roofs. Comparison of green and simulated conventional roofs indicated that the former were able to mitigate the peak of runoff and could delay the start of runoff. These characteristics are important for most source control measures. The recorded rainfall and runoff data displayed a non-linear relationship. Also, the results indicated that continuous time series modelling would be a more appropriate technique than using peak rainfall intensity methods for green roof design and simulation.

  15. Green roofs for a drier world: effects of hydrogel amendment on substrate and plant water status.

    Science.gov (United States)

    Savi, Tadeja; Marin, Maria; Boldrin, David; Incerti, Guido; Andri, Sergio; Nardini, Andrea

    2014-08-15

    Climate features of the Mediterranean area make plant survival over green roofs challenging, thus calling for research work to improve water holding capacities of green roof systems. We assessed the effects of polymer hydrogel amendment on the water holding capacity of a green roof substrate, as well as on water status and growth of Salvia officinalis. Plants were grown in green roof experimental modules containing 8 cm or 12 cm deep substrate (control) or substrate mixed with hydrogel at two different concentrations: 0.3 or 0.6%. Hydrogel significantly increased the substrate's water content at saturation, as well as water available to vegetation. Plants grown in 8 cm deep substrate mixed with 0.6% of hydrogel showed the best performance in terms of water status and membrane integrity under drought stress, associated to the lowest above-ground biomass. Our results provide experimental evidence that polymer hydrogel amendments enhance water supply to vegetation at the establishment phase of a green roof. In particular, the water status of plants is most effectively improved when reduced substrate depths are used to limit the biomass accumulation during early growth stages. A significant loss of water holding capacity of substrate-hydrogel blends was observed after 5 months from establishment of the experimental modules. We suggest that cross-optimization of physical-chemical characteristics of hydrogels and green roof substrates is needed to improve long term effectiveness of polymer-hydrogel blends.

  16. Cladonia lichens on extensive green roofs: evapotranspiration, substrate temperature, and albedo.

    Science.gov (United States)

    Heim, Amy; Lundholm, Jeremy

    2013-01-01

    Green roofs are constructed ecosystems that provide ecosystem services in urban environments. Shallow substrate green roofs subject the vegetation layer to desiccation and other environmental extremes, so researchers have evaluated a variety of stress-tolerant vegetation types for green roof applications. Lichens can be found in most terrestrial habitats.  They are able to survive extremely harsh conditions, including frequent cycles of desiccation and rehydration, nutrient-poor soil, fluctuating temperatures, and high UV intensities. Extensive green roofs (substrate depth green roofs.  In a modular green roof system, we tested the effect of Cladonia lichens on substrate temperature, water loss, and albedo compared to a substrate-only control. Overall, the Cladonia modules had significantly cooler substrate temperatures during the summer and significantly warmer temperatures during the fall.  Additionally, the Cladonia modules lost significantly less water than the substrate-only control. This implies that they may be able to benefit neighboring vascular plant species by reducing water loss and maintaining favorable substrate temperatures.

  17. Effects of substrate properties on the hydraulic and thermal behavior of a green roof

    Science.gov (United States)

    Sandoval, V. P.; Suarez, F. I.; Victorero, F.; Bonilla, C.; Gironas, J. A.; Vera, S.; Bustamante, W.; Rojas, V.; Pasten, P.

    2014-12-01

    Green roofs are a sustainable urban development solution that incorporates a growing media (also known as substrate) and vegetation into infrastructures to reach additional benefits such as the reduction of: rooftop runoff peak flows, roof surface temperatures, energy utilized for cooling/heating buildings, and the heat island effect. The substrate is a key component of the green roof that allows achieving these benefits. It is an artificial soil that has an improved behavior compared to natural soils, facilitating vegetation growth, water storage and typically with smaller densities to reduce the loads over the structures. Therefore, it is important to study the effects of substrate properties on green roof performance. The objective of this study is to investigate the physical properties of four substrates designed to improve the behavior of a green roof, and to study their impact on the efficiency of a green roof. The substrates that were investigated are: organic soil; crushed bricks; a mixture of mineral soil with perlite; and a mixture of crushed bricks and organic soil. The thermal properties (thermal conductivity, volumetric heat capacity and thermal diffusivity) were measured using a dual needle probe (Decagon Devices, Inc.) at different saturation levels, and the hydraulic properties were measured with a constant head permeameter (hydraulic conductivity) and a pressure plate extractor (water retention curve). This characterization, combined with numerical models, allows understanding the effect of these properties on the hydraulic and thermal behavior of a green roof. Results show that substrates composed by crushed bricks improve the thermal insulation of infrastructures and at the same time, retain more water in their pores. Simulation results also show that the hydraulic and thermal behavior of a green roof strongly depends on the moisture content prior to a rainstorm.

  18. Water quantity and quality response of a green roof to storm events: Experimental and monitoring observations.

    Science.gov (United States)

    Carpenter, Corey M G; Todorov, Dimitar; Driscoll, Charles T; Montesdeoca, Mario

    2016-11-01

    Syracuse, New York is working under a court-ordered agreement to limit combined sewer overflows (CSO) to local surface waters. Green infrastructure technologies, including green roofs, are being implemented as part of a CSO abatement strategy and to develop co-benefits of diminished stormwater runoff, including decreased loading of contaminants to the wastewater system and surface waters. The objective of this study was to examine the quantity and quality of discharge associated with precipitation events over an annual cycle from a green roof in Syracuse, NY and to compare measurements from this monitoring program with results from a roof irrigation experiment. Wet deposition, roof drainage, and water quality were measured for 87 storm events during an approximately 12 month period over 2011-2012. Water and nutrient (total phosphorus, total nitrogen, and dissolved organic carbon) mass balances were conducted on an event basis to evaluate retention annually and during the growing and non-growing seasons. These results are compared with a hydrological manipulation experiment, which comprised of artificially watering of the roof. Loadings of nutrients were calculated for experimental and actual storms using the concentration of nutrients and the flow data of water discharging the roof. The green roof was effective in retaining precipitation quantity from storm events (mean percent retention 96.8%, SD = 2.7%, n = 87), although the relative fraction of water retained decreased with increases in the size of the event. There was no difference in water retention of the green roof for the growing and non-growing seasons. Drainage waters exhibited high concentration of nutrients during the warm temperature growing season, particularly total nitrogen and dissolved organic carbon. Overall, nutrient losses were low because of the strong retention of water. However, there was marked variation in the retention of nutrients by season due to variations in concentrations in roof

  19. Study on the Thermal Effects and Air Quality Improvement of Green Roof

    Directory of Open Access Journals (Sweden)

    Heng Luo

    2015-03-01

    Full Text Available Heat island phenomenon and air quality deterioration issues are two major problems that have occurred during the process of urbanization, especially in developing countries. A number of measures have been proposed, among which roof greening is considered as a promising one due to its outstanding performance in thermal effects as well as air quality improvement. A self-maintenance system, termed the Green Roof Manager (GRM, which comprises the irrigation and shadowing subsystems, is proposed in this paper, focusing on the automatic and reliable operation of the roof greening system rather than exploiting new plant species. A three month long experiment was set up, resulting in the observation that a 14.7% of, on average, temperature reduction can be achieved in summer after deploying the GRM system. During a 24-hour monitoring experiment the PM2.5 concentrations above the GRM was reduced by up to 14.1% over the bare roof.

  20. Drought versus heat: What's the major constraint on Mediterranean green roof plants?

    Science.gov (United States)

    Savi, Tadeja; Dal Borgo, Anna; Love, Veronica L; Andri, Sergio; Tretiach, Mauro; Nardini, Andrea

    2016-10-01

    Green roofs are gaining momentum in the arid and semi-arid regions due to their multiple benefits as compared with conventional roofs. One of the most critical steps in green roof installation is the selection of drought and heat tolerant species that can thrive under extreme microclimate conditions. We monitored the water status, growth and survival of 11 drought-adapted shrub species grown on shallow green roof modules (10 and 13cm deep substrate) and analyzed traits enabling plants to cope with drought (symplastic and apoplastic resistance) and heat stress (root membrane stability). The physiological traits conferring efficiency/safety to the water transport system under severe drought influenced plant water status and represent good predictors of both plant water use and growth rates over green roofs. Moreover, our data suggest that high substrate temperature represents a stress factor affecting plant survival to a larger extent than drought per se. In fact, the major cause influencing seedling survival on shallow substrates was the species-specific root resistance to heat, a single and easy measurable trait that should be integrated into the methodological framework for screening and selection of suitable shrub species for roof greening in the Mediterranean.

  1. Discussion on the design of roof greening%屋顶绿化设计探讨

    Institute of Scientific and Technical Information of China (English)

    和晓艳

    2012-01-01

    This paper researched the design of roof greening,explained that the roof greening was the effective method to use city roof space,pointed out its key design was how to reduce the roof load,plants plant select etc..In the design should follow the design principles.Point out the design elements used in land greening could also be used in roof greening,the roof greening design elements had no restrictions.%对屋顶绿化的设计进行了研究,说明屋顶绿化是利用城市屋面空间的有效方法,指出其设计关键在于如何减轻屋顶荷载,植物种植选择等,在设计时要遵循设计原则,提出地面绿化中可以使用的设计要素也可以用于屋顶绿化,屋顶绿化设计要素种类没有限制。

  2. Mapping the Green Infrastructure potential - and it's water-energy impacts on New York City roof Tops

    Science.gov (United States)

    Engström, Rebecka; Destouni, Georgia; Howells, Mark

    2017-04-01

    Green Roofs have the potential to provide multiple services in cities. Besides acting as carbon sinks, providing noise reduction and decreasing air pollution - without requiring any additional "land-use" in a city (only roof-use), green roofs have a quantifiable potential to reduce direct and indirect energy and water use. They enhance the insulating capacity of a conventional residential roof and thereby decrease both cooling demands in summer and heating demands in winter. The former is further mitigated by the cooling effect of evapotranspiration from the roofs In New York City green roofs are additionally a valuable component of reducing "combined sewer overflows", as these roofs can retain storm water. This can improve water quality in the city's rivers as well as decrease the total volume of water treated in the city's wastewater treatment plants, thereby indirectly reduce energy demands. The impacts of green roofs on NYC's water-energy nexus has been initially studied (Engström et. al, forthcoming). The present study expands that work to more comprehensively investigate the potential of this type of nature-based solution in a dense city. By employing Geographical Information Systems analysis, the roof top area of New York City is analysed and roof space suitable for green roofs of varying types (ranging from extensive to intensive) are mapped and quantified. The total green roof area is then connected with estimates of potential water-energy benefits (and costs) of each type of green roof. The results indicate where green roofs can be beneficially installed throughout the city, and quantifies the related impacts on both water and energy use. These outputs can provide policy makers with valuable support when facing investment decisions in green infrastructure, in a city where there is great interest for these types of nature-based solutions.

  3. The green build-out model : quantifying stormwater benefits of trees and green roofs in Washington, DC

    Energy Technology Data Exchange (ETDEWEB)

    Deutsch, B.; Whitlow, H. [Casey Trees, Washington, DC (United States); Sullivan, M.; Savineau, A.; Busiek, B. [Limno-Tech Inc., Ann Arbor, MI (United States)

    2007-07-01

    The United States Environmental Protection Agency has listed nearly all of the waters in the District of Columbia as impaired. This includes the Anacostia and Potomac rivers and Rock Creek, whose primary sources of pollution are sewer overflows and stormwater. This paper presented the research findings from the Environmental Protection Agency's Water Quality Cooperative Agreement grant entitled the Green Build-out Model. It builds upon research conducted by a public-private partnership between Casey Trees, a non-profit organization that protects tree cover in Washington DC, and Limno-Tech Inc., an environmental engineering firm that built the hydrologic and hydraulic model for the Water and Sewer Authority. Both green roofs and trees lower the volume of runoff, reduce peak rates of runoff, and improve water quality. However, these benefits have not been evaluated nor quantified on a cumulative, sewershed and city-wide basis for engineers, landscape architects, and planners to integrate green roofs and trees into solutions for stormwater permitting requirements. This research questioned how many green roofs and trees are needed to make a difference to stormwater management in the District of Columbia. It investigated the relationships between tree cover, green roof cover, larger tree boxes, and key hydrologic and hydraulic variables such as stormwater and combined sewer overflow volume, flow rate, and frequency. Reductions in pollutant loads resulting from lower stormwater volumes were also estimated along with operational savings from reduced pumping and treatment of stormwater volumes. All of the modeled green roofs were extensive green roofs with three to four inches of growth media. Extensive green roofs were assumed city-wide for their potential to reduce pollutant load from stormwater flow; operational savings from stormwater flow reductions; and, general hydrologic relationships. It was concluded that trees and green roofs should be factored into the

  4. Water quality and quantity investigation of green roofs in a dry climate.

    Science.gov (United States)

    Beecham, S; Razzaghmanesh, M

    2015-03-01

    Low-energy pollutant removal strategies are now being sought for water sensitive urban design. This paper describes investigations into the water quality and quantity of sixteen, low-maintenance and unfertilized intensive and extensive green roof beds. The factors of Slope (1° and 25°), Depth (100 mm and 300 mm), Growing media (type A, type B and type C) and Species (P1, P2 and P3) were randomized according to a split-split plot design. This consisted of twelve vegetated green roof beds and four non-vegetated beds as controls. Stormwater runoff was collected from drainage points that were installed in each area. Samples of run-off were collected for five rainfall events and analysed for water retention capacity and the water quality parameters of NO₂, NO₃, NH₄, PO₄, pH, EC, TDS, Turbidity, Na, Ca, Mg and K. The results indicated significant differences in terms of stormwater water quality and quantity between the outflows of vegetated and non-vegetated systems. The water retention was between 51% and 96% and this range was attributed to the green roof configurations in the experiment. Comparing the quality of rainfall as inflow, and the quality of runoff from the systems showed that green roofs generally acted as a source of pollutants in this study. In the vegetated beds, the intensive green roofs performed better than the extensive beds with regard to outflow quality while in the non-vegetated beds, the extensive beds performed better than intensive systems. This highlights the importance of vegetation in improving water retention capacity as well as the role of vegetation in enhancing pollutant removal in green roof systems. In addition growing media with less organic matter had better water quality performance. Comparison of these results with national and international standards for water reuse confirmed that the green roof outflow was suitable for non-potable uses such as landscape irrigation and toilet flushing.

  5. Moisture content behaviour in extensive green roofs during dry periods: the influence of vegetation and substrate characteristics

    OpenAIRE

    Berretta, C; Poe, S.; Stovin, V.

    2014-01-01

    Evapotranspiration (ET) is a key parameter that influences the stormwater retention capacity, and thus the hydrological performance, of green roofs. This paper investigates how the moisture content in extensive green roofs varies during dry periods due to evapotranspiration. The study is supported by 29 months continuous field monitoring of the moisture content within four green roof test beds. The beds incorporated three different substrates, with three being vegetated with sedum and one lef...

  6. A two-stage storage routing model for green roof runoff detention.

    Science.gov (United States)

    Vesuviano, Gianni; Sonnenwald, Fred; Stovin, Virginia

    2014-01-01

    Green roofs have been adopted in urban drainage systems to control the total quantity and volumetric flow rate of runoff. Modern green roof designs are multi-layered, their main components being vegetation, substrate and, in almost all cases, a separate drainage layer. Most current hydrological models of green roofs combine the modelling of the separate layers into a single process; these models have limited predictive capability for roofs not sharing the same design. An adaptable, generic, two-stage model for a system consisting of a granular substrate over a hard plastic 'egg box'-style drainage layer and fibrous protection mat is presented. The substrate and drainage layer/protection mat are modelled separately by previously verified sub-models. Controlled storm events are applied to a green roof system in a rainfall simulator. The time-series modelled runoff is compared to the monitored runoff for each storm event. The modelled runoff profiles are accurate (mean Rt(2) = 0.971), but further characterization of the substrate component is required for the model to be generically applicable to other roof configurations with different substrate.

  7. Green roofs: A possible best management practice for enhancing ...

    African Journals Online (AJOL)

    ... roofs: A possible best management practice for enhancing the environmental quality ... erodes the natural ability of the locale to perform its ecosystem services. ... structural components, formulation of guidelines for the industry, government ...

  8. Physical properties and hydrological response of green roof substrates based on recycled construction materials

    Science.gov (United States)

    Vanwalleghem, Tom; Hayas, Antonio; Jiménez-Quiñones, Daniel; Peña, Adolfo; Giráldez, Juan Vicente

    2015-04-01

    Green roofs in urban areas improve the building's energy efficiency and provide a wide array of additional environmental benefits. Characterizing and predicting the physical properties and hydrological response of green roofs is necessary to understand the roof's heat balance, which is controlled to a large extent by the substrate's water content, to predict the runoff response and functioning as a part of sustainable urban drainage systems and to plan irrigation of the plants in drier climates. This study examines 10 different extensive green roof substrates, based on recycled construction materials. Green roof simulation decks were installed in boxes of 0,6 m x 0,4 m to a depth of 70 mm, 10 with and 10 without plants. Total water holding capacity of the substrates varied between 10,4 - 23,9 %, with an additional 19 % retained by the drainage layer and geotextiles used in the simulation deck. An important compaction of 30 % on average was observed after 1,5 months. Final bulk densities are between 1457 - 1993 kg m-3. In an evaporation experiment, it was shown that the water evaporated from the green roofs is controlled mainly by the relative moisture content. Substrate properties exerted only a secondary control, with the lowest evaporation rates from the substrates with highest coarse crushed aggregate content and with the highest clay content. The evaporation model proposed here was shown to work well to simulate the evolution of the water balance and therefore the specific unit weight over longer time periods in all substrates, with a Nash-Sutcliffe model efficiency of 0.989. Finally, plants were found to grow satisfactorily in all substrates. Therefore, when regular irrigation is provided, it was concluded that green roofs based on recycled construction materials are a viable option. Future research will have to explore the long-term plant dynamics under water-limited conditions.

  9. Do vegetated rooftops attract more mosquitoes? Monitoring disease vector abundance on urban green roofs.

    Science.gov (United States)

    Wong, Gwendolyn K L; Jim, C Y

    2016-12-15

    Green roof, an increasingly common constituent of urban green infrastructure, can provide multiple ecosystem services and mitigate climate-change and urban-heat-island challenges. Its adoption has been beset by a longstanding preconception of attracting urban pests like mosquitoes. As more cities may become vulnerable to emerging and re-emerging mosquito-borne infectious diseases, the knowledge gap needs to be filled. This study gauges the habitat preference of vector mosquitoes for extensive green roofs vis-à-vis positive and negative control sites in an urban setting. Seven sites in a university campus were selected to represent three experimental treatments: green roofs (GR), ground-level blue-green spaces as positive controls (PC), and bare roofs as negative controls (NC). Mosquito-trapping devices were deployed for a year from March 2015 to 2016. Human-biting mosquito species known to transmit infectious diseases in the region were identified and recorded as target species. Generalized linear models evaluated the effects of site type, season, and weather on vector-mosquito abundance. Our model revealed site type as a significant predictor of vector mosquito abundance, with considerably more vector mosquitoes captured in PC than in GR and NC. Vector abundance was higher in NC than in GR, attributed to the occasional presence of water pools in depressions of roofing membrane after rainfall. Our data also demonstrated seasonal differences in abundance. Weather variables were evaluated to assess human-vector contact risks under different weather conditions. Culex quinquefasciatus, a competent vector of diseases including lymphatic filariasis and West Nile fever, could be the most adaptable species. Our analysis demonstrates that green roofs are not particularly preferred by local vector mosquitoes compared to bare roofs and other urban spaces in a humid subtropical setting. The findings call for a better understanding of vector ecology in diverse urban landscapes

  10. The growth and survival of plants in urban green roofs in a dry climate.

    Science.gov (United States)

    Razzaghmanesh, M; Beecham, S; Kazemi, F

    2014-04-01

    Green roofs as one of the components of water-sensitive urban design have become widely used in recent years. This paper describes performance monitoring of four prototype-scale experimental green roofs in a northern suburb of Adelaide, South Australia, undertaken over a 1-year period. Four species of indigenous Australian ground cover and grass species comprising Carpobrotus rossii, Lomandra longifolia 'Tanika,' Dianella caerula 'Breeze' and Myoporum parvifolium were planted in extensive and intensive green roof configurations using two different growing media. The first medium consisted of crushed brick, scoria, coir fibre and composted organics while the second comprised scoria, composted pine bark and hydro-cell flakes. Plant growth indices including vertical and horizontal growth rate, leaf succulence, shoot and root biomasses, water use efficiency and irrigation regimes were studied during a 12-month period. The results showed that the succulent species, C. rossii, can best tolerate the hot, dry summer conditions of South Australia, and this species showed a 100% survival rate and had the maximum horizontal growth rate, leaf succulence, shoot biomass and water use efficiency. All of the plants in the intensive green roofs with the crushed brick mix media survived during the term of this study. It was shown that stormwater can be used as a source of irrigation water for green roofs during 8 months of the year in Adelaide. However, supplementary irrigation is required for some of the plants over a full annual cycle.

  11. A green roof experimental site in the Mediterranean climate: the storm water quality issue.

    Science.gov (United States)

    Gnecco, Ilaria; Palla, Anna; Lanza, Luca G; La Barbera, Paolo

    2013-01-01

    Since 2007, the University of Genoa has been carrying out a monitoring programme to investigate the hydrologic response of green roofs in the Mediterranean climate by installing a green roof experimental site. In order to assess the influence of green roofs on the storm water runoff quality, water chemistry data have been included in the monitoring programme since 2010, providing rainfall and outflow data. For atmospheric source, the bulk deposition is collected to evaluate the role of the overall atmospheric deposition in storm water runoff quality. For subsurface outflow, a maximum of 24 composite samples are taken on an event basis, thus aiming at a full characterization of the outflow hydrograph. Water chemistry data reveal that the pollutant loads associated with green roof outflow is low; in particular, solids and metal concentrations are lower than values generally observed in storm water runoff from traditional rooftops. The concentration values of chemical oxygen demand, total dissolved solids, Fe, Ca and K measured in the subsurface outflow are significantly higher than those observed in the bulk deposition (p < 0.05). With respect to the atmospheric deposition, the green roof behaviour as a sink/source of pollutants is investigated based on both concentration and mass.

  12. Using soil microbial inoculations to enhance substrate performance on extensive green roofs.

    Science.gov (United States)

    Molineux, Chloe J; Gange, Alan C; Newport, Darryl J

    2017-02-15

    Green roofs are increasing in popularity in the urban environment for their contribution to green infrastructure; but their role for biodiversity is not often a design priority. Maximising biodiversity will impact positively on ecosystem services and is therefore fundamental for achieving the greatest benefits from green roofs. Extensive green roofs are lightweight systems generally constructed with a specialised growing medium that tends to be biologically limited and as such can be a harsh habitat for plants to thrive in. Thus, this investigation aimed to enhance the soil functioning with inoculations of soil microbes to increase plant diversity, improve vegetation health/performance and maximise access to soil nutrients. Manipulations included the addition of mycorrhizal fungi and a microbial mixture ('compost tea') to green roof rootzones, composed mainly of crushed brick or crushed concrete. The study revealed that growing media type and depth play a vital role in the microbial ecology of green roofs, with complex relationships between depth and type of substrate and the type of microbial inoculant applied, with no clear pattern being observed. For bait plant measurements (heights, leaf numbers, root/shoot biomass, leaf nutrients), a compost tea may have positive effects on plant performance when grown in substrates of shallower depths (5.5cm), even one year after inoculums are applied. Results from the species richness surveys show that diversity was significantly increased with the application of an AM fungal treatment and that overall, results suggest that brick-based substrate blends are most effective for vegetation performance as are deeper depths (although this varied with time). Microbial inoculations of green roof habitats appeared to be sustainable; they need only be done once for benefits to still been seen in subsequent years where treatments are added independently (not in combination). They seem to be a novel and viable method of enhancing

  13. Plant species and functional group combinations affect green roof ecosystem functions.

    Directory of Open Access Journals (Sweden)

    Jeremy Lundholm

    Full Text Available BACKGROUND: Green roofs perform ecosystem services such as summer roof temperature reduction and stormwater capture that directly contribute to lower building energy use and potential economic savings. These services are in turn related to ecosystem functions performed by the vegetation layer such as radiation reflection and transpiration, but little work has examined the role of plant species composition and diversity in improving these functions. METHODOLOGY/PRINCIPAL FINDINGS: We used a replicated modular extensive (shallow growing- medium green roof system planted with monocultures or mixtures containing one, three or five life-forms, to quantify two ecosystem services: summer roof cooling and water capture. We also measured the related ecosystem properties/processes of albedo, evapotranspiration, and the mean and temporal variability of aboveground biomass over four months. Mixtures containing three or five life-form groups, simultaneously optimized several green roof ecosystem functions, outperforming monocultures and single life-form groups, but there was much variation in performance depending on which life-forms were present in the three life-form mixtures. Some mixtures outperformed the best monocultures for water capture, evapotranspiration, and an index combining both water capture and temperature reductions. Combinations of tall forbs, grasses and succulents simultaneously optimized a range of ecosystem performance measures, thus the main benefit of including all three groups was not to maximize any single process but to perform a variety of functions well. CONCLUSIONS/SIGNIFICANCE: Ecosystem services from green roofs can be improved by planting certain life-form groups in combination, directly contributing to climate change mitigation and adaptation strategies. The strong performance by certain mixtures of life-forms, especially tall forbs, grasses and succulents, warrants further investigation into niche complementarity or

  14. Thermal and water regime of green roof segments filled with Technosol

    Science.gov (United States)

    Jelínková, Vladimíra; Šácha, Jan; Dohnal, Michal; Skala, Vojtěch

    2016-04-01

    Artificial soil systems and structures comprise appreciable part of the urban areas and are considered to be perspective for number of reasons. One of the most important lies in contribution of green roofs and facades to the heat island effect mitigation, air quality improvement, storm water reduction, etc. The aim of the presented study is to evaluate thermal and water regime of the anthropogenic soil systems during the first months of the construction life cycle. Green roof test segments filled with two different anthropogenic soils were built to investigate the benefits of such systems in the temperate climate. Temperature and water balance measurements complemented with meteorological observations and knowledge of physical properties of the soil substrates provided basis for detailed analysis of thermal and hydrological regime. Water balance of green roof segments was calculated for available vegetation seasons and individual rainfall events. On the basis of an analysis of individual rainfall events rainfall-runoff dependency was found for green roof segments. The difference between measured actual evapotranspiration and calculated potential evapotranspiration was discussed on period with contrasting conditions in terms of the moisture stress. Thermal characteristics of soil substrates resulted in highly contrasting diurnal variation of soils temperatures. Green roof systems under study were able to reduce heat load of the roof construction when comparing with a concrete roof construction. Similarly, received rainfall was significantly reduced. The extent of the rainfall reduction mainly depends on soil, vegetation status and experienced weather patterns. The research was realized as a part of the University Centre for Energy Efficient Buildings supported by the EU and with financial support from the Czech Science Foundation under project number 14-10455P.

  15. Roof Greening Practice of Minhang District of Shanghai%上海市闵行区屋顶绿化实践

    Institute of Scientific and Technical Information of China (English)

    蒋春霞

    2011-01-01

    The roof greening with an area of 350 000 m2 has been completed in Minhang District of Shanghai during the "Eleventh Five-Year Plan" and valuable experience has been gained through the continuous practices, which could be reference for other places. However, there are still many problems in the planning and design of roof greening, which need further discussion and in-depth study. Urban planning, greening and construction should be combined and develop together in the future, the understanding of the significance of roof greening should be enhanced, new products of roof greening should be further developed and construction techniques should be improved, which would enable roof greening develop more over cities and play its unique social and ecological benefits.%上海市闵行区在“十一五”期间建成了35万m2形式多样的屋顶绿化,在不断实践中取得了宝贵经验,可供各地实践部门参考.但在屋顶绿化规划设计的过程中,尚有诸多问题有待日后探讨和深入研究,在今后,城市规划、绿化和建筑应相结合,齐头并进,城市绿化部门应加强对屋顶绿化重要性的认识,同时进一步开发、研制屋顶绿化的新产品、提高施工技术,以至让屋顶绿化更多地在城市上空发展,真正发挥其特有的社会和生态效益.

  16. Effect of P-Reactive Drainage Aggregates on Green Roof Runoff Quality

    Directory of Open Access Journals (Sweden)

    Agnieszka Karczmarczyk

    2014-08-01

    Full Text Available The main hypothesis of the presented study is that the negative effect of phosphorus leaching from a green roof substrate can be reduced by including P-reactive material in a drainage layer. In this work, different aggregates (Pollytag®, lightweight expanded clay aggregates, chalcedony, serpentynite and crushed autoclaved aerated concrete to be used as the green roof drainage layer are described. Physical parameters, e.g., granulometric composition, water absorption, bulk density and porosity are assessed. A phosphorus sorption isotherm and a kinetic test were performed. Physical and chemical characteristics of the materials were used as a base for choosing the best media for the drainage layer. The P-removal efficiency of crushed autoclaved aerated concrete was confirmed in a column experiment. Adding the implementation of the P-reactive material in a drainage layer during construction can reduce the negative effect of substrate on green roof runoff quality.

  17. Leaf and life history traits predict plant growth in a green roof ecosystem.

    Science.gov (United States)

    Lundholm, Jeremy; Heim, Amy; Tran, Stephanie; Smith, Tyler

    2014-01-01

    Green roof ecosystems are constructed to provide services such as stormwater retention and urban temperature reductions. Green roofs with shallow growing media represent stressful conditions for plant survival, thus plants that survive and grow are important for maximizing economic and ecological benefits. While field trials are essential for selecting appropriate green roof plants, we wanted to determine whether plant leaf traits could predict changes in abundance (growth) to provide a more general framework for plant selection. We quantified leaf traits and derived life-history traits (Grime's C-S-R strategies) for 13 species used in a four-year green roof experiment involving five plant life forms. Changes in canopy density in monocultures and mixtures containing one to five life forms were determined and related to plant traits using multiple regression. We expected traits related to stress-tolerance would characterize the species that best grew in this relatively harsh setting. While all species survived to the end of the experiment, canopy species diversity in mixture treatments was usually much lower than originally planted. Most species grew slower in mixture compared to monoculture, suggesting that interspecific competition reduced canopy diversity. Species dominant in mixture treatments tended to be fast-growing ruderals and included both native and non-native species. Specific leaf area was a consistently strong predictor of final biomass and the change in abundance in both monoculture and mixture treatments. Some species in contrasting life-form groups showed compensatory dynamics, suggesting that life-form mixtures can maximize resilience of cover and biomass in the face of environmental fluctuations. This study confirms that plant traits can be used to predict growth performance in green roof ecosystems. While rapid canopy growth is desirable for green roofs, maintenance of species diversity may require engineering of conditions that favor less

  18. The Influence of Ambient Temperature on Green Roof R-values

    Science.gov (United States)

    Cox, Bryce Kevin

    Green roofs can be an effective and appealing way to increase the energy efficiency of buildings by providing active insulation. As plants in the green roof transpire, there is a reduction in heat flux that is conducted through the green roof. The R-value, or thermal resistance, of a green roof is an effective measurement of thermal performance because it can be easily included in building energy calculations applicable to many different buildings and situations. The purpose of this study was to determine if an increase in ambient temperature would cause an increase in the R-value of green roofs. Test trays containing green roof materials were tested in a low speed wind tunnel equipped to determine the R-value of the trays. Three different plant species were tested in this study, ryegrass (Lolium perenne), sedum (Sedum hispanicum), and vinca (Vinca minor ). For each test in this study the relative humidity was maintained at 45% and the soil was saturated with water. The trays were tested at four different ambient temperatures, ranging from room temperature to 120ºF. The resulting R-values for sedum ranged from 1.37 to 3.28 ft2hºF/BTU, for ryegrass the R-values ranged from 2.15 to 3.62 ft2hºF/BTU, and for vinca the R-values ranged from 3.15 to 5.19 ft2hºF/BTU. The average R-value for all the tests in this study was 3.20 ft2hºF/BTU. The results showed an increase in R-value with increasing temperature. Applying an ANOVA analysis to the data, the relationship between temperature and R-value for all three plant species was found to be statistically significant.

  19. Restoring pre-development conditions in a urban environment using green roofs

    Science.gov (United States)

    Palla, Anna; Gnecco, Ilaria; Lanza, Luca G.

    2010-05-01

    As development progresses in a urban environment, the impervious areas that rapidly contribute runoff to the receiving water bodies increase while the pervious areas that store and deliver subsurface flow over periods of hours, days or weeks diminish, with the direct consequence of higher runoff rates and volumes and shorter times of concentration. The construction of impervious surfaces modifies the surrounding soils through engineered compaction and eliminates superficial soil and its role as a significant pervious storage interface between the subsurface and the atmosphere. There are documented case studies that conclusively link urbanization and increased watershed imperviousness to hydrologic impacts on streams. The Effective Impervious Area (EIA) in a watershed is the impervious area directly connected to the storm drainage system that contributes to increased storm water volumes and runoff rates. It is shown in the literature that a reduction of EIA could compensate the adverse impact of possible global warming scenarios on urban hydrology and in particular on the efficiency of a combined sewer system. In this paper, the implementation of green roofs is analyzed as a technique able to reduce the amount of EIA in order to mitigate the impact of urbanization on the hydrologic response of the urban catchment of Colle Ometti in the town of Genoa (Italy). Although no green roof installations are now present in the area, this study modelled - using extensive green roof details - the hydrologic effects of hypothetical roof greening scenarios. The modelling of green roof systems was undertaken using the EPA SWMM and was calibrated and validated on a small size green roof test bed completed in September 2007 in the laboratory of the Department of Civil, Environmental and Architectural Engineering (DICAT - University of Genova).

  20. Leaf and life history traits predict plant growth in a green roof ecosystem.

    Directory of Open Access Journals (Sweden)

    Jeremy Lundholm

    Full Text Available Green roof ecosystems are constructed to provide services such as stormwater retention and urban temperature reductions. Green roofs with shallow growing media represent stressful conditions for plant survival, thus plants that survive and grow are important for maximizing economic and ecological benefits. While field trials are essential for selecting appropriate green roof plants, we wanted to determine whether plant leaf traits could predict changes in abundance (growth to provide a more general framework for plant selection. We quantified leaf traits and derived life-history traits (Grime's C-S-R strategies for 13 species used in a four-year green roof experiment involving five plant life forms. Changes in canopy density in monocultures and mixtures containing one to five life forms were determined and related to plant traits using multiple regression. We expected traits related to stress-tolerance would characterize the species that best grew in this relatively harsh setting. While all species survived to the end of the experiment, canopy species diversity in mixture treatments was usually much lower than originally planted. Most species grew slower in mixture compared to monoculture, suggesting that interspecific competition reduced canopy diversity. Species dominant in mixture treatments tended to be fast-growing ruderals and included both native and non-native species. Specific leaf area was a consistently strong predictor of final biomass and the change in abundance in both monoculture and mixture treatments. Some species in contrasting life-form groups showed compensatory dynamics, suggesting that life-form mixtures can maximize resilience of cover and biomass in the face of environmental fluctuations. This study confirms that plant traits can be used to predict growth performance in green roof ecosystems. While rapid canopy growth is desirable for green roofs, maintenance of species diversity may require engineering of conditions that

  1. City of Seattle green roof policy development through extended performance monitoring as a basis for hydrologic modeling

    Energy Technology Data Exchange (ETDEWEB)

    Wachter, H.M.; Berkompas, B.; Taylor, W.; Marx, K.W. [Taylor Associates, Inc., Seattle, WA (United States); Lilly, D. [City of Seattle, Seattle Public Utilities, Seattle, WA (United States)

    2007-07-01

    The advantages offered by green roofs range from improvement in architectural and landscape aesthetics to reductions in building energy costs. Seattle Public Utilities (SPU) is encouraging sustainable community development through new policies and regulations that promote green roof installation on public and commercial rooftops in Seattle's urban center. An understanding of climate-specific green roof performance is required in order to develop an accurate representation of the stormwater benefits of green roofs. This paper explored the relative importance of green roofs in storm water management and low impact development (LID) in various areas of Seattle. It also examined the relative effectiveness and applicability of green roofs under various conditions and in various parts of the city compared to other LID strategies such as Seattle's natural drainage systems (NDS) designs, swales and ponds, rain gardens, rainwater harvesting, and porous pavements. SPU has launched a research program led by Taylor Associates, a Seattle aquatic sciences consulting firm, to monitor the rainfall, evapotranspiration, soil storage, and runoff on several existing green roofs over a three year period. In particular, the city is interested in identifying LID features that, independently or in combination with other strategies, effectively attenuate peak flows to potentially reduce combined sewer overflow (CSO) events. Long-term hydrologic records will be used to calibrate a continuous hydrologic model to enable the simulation of green roof performance based on a 40-year rainfall record. The objective of this effort is to use long-term simulation as a basis for policy development regarding the use of green roofs. Future funding may expand the study to investigate the benefit that green roofs may provide for roof runoff water quality in Seattle's most urban areas. 23 refs., 2 tabs., 3 figs.

  2. Impact of climate and vegetation type on evapotranspiration from green roofs

    Science.gov (United States)

    Sia, M. E.; Robinson, C. E.; O'Carroll, D. M.; Voogt, J. A.; Smart, C. C.; Way, D. A.

    2015-12-01

    Green roofs are an increasingly popular low impact development tool used to mitigate the adverse effects of urbanization and the loss of vegetated spaces. The benefits of green roofs include reducing stormwater volume and peak flows, reducing building energy loads, and mitigating the urban heat island effect. Evapotranspiration (ET) is a key process fundamental to hydrologic and thermal performance of green roofs. For example, ET governs the water storage volume available in the soil medium and thus the ability of the green roof to retain and attenuate stormwater. Green roof design considerations such as soil medium depth and plant type impact ET rates. Additionally, climate has a strong impact on ET rates. To date, the influence between climate and green roof design factors (e.g. vegetation type and soil medium depth) on ET rates have not been well quantified. We performed a field study to evaluate the impact of climate, vegetation type, and soil medium depth on ET rates from extensive modular green roofs over prolonged drying periods. Three Canadian cities with distinct climates were chosen as field sites: London, ON, Calgary, AB, and Halifax, NS. At each site, daily module weights were recorded from May to August in 2013 and 2014 for approximately 40 green roof modules. These modules were divided into four vegetation treatments (three single species and one mixed species), and each treatment was divided into two groups of soil medium depth (10 cm or 15 cm). Daily ET rates and seasonal moisture loss were calculated and compared for the modules to determine which treatment provided the highest ET rates. The root depth profile, leaf area index, and stomatal resistance were also measured. On average, daily ET rates among the vegetation treatments did not vary greatly, however, observations on plant survival indicate which plant types are best suited for each site. In all three sites, mixed species in 15 cm of soil medium had higher seasonal moisture loss compared to

  3. Applications of Extensive Green-roof Systems in Contributing to Sustainable Development in Densely Populated Cities: a Hong Kong Study

    Directory of Open Access Journals (Sweden)

    Xiaoling Zhang

    2011-03-01

    Full Text Available Developed cities such as Hong Kong are usually densely populated. Since the land is limited, high-rise buildings are constructed. When the building height becomes higher, air flow is reduced and heat is trapped among high-rise buildings. Air temperature will be greatly increased and air pollution becomes a serious problem. This creates a walled building problem. To reduce air temperature caused by the wall-effects, various methods have been developed in the previous studies. One typical method is the use of green roof systems. The application of extensive green roofs on the existing building rooftops has been recommended in Hong Kong since 2001. The advantage of this practice is that no additional floor area is required and it can also improve urban greenery. Although a green roof system has been introduced and adopted in Hong Kong since 2001, the emphasis is mainly given to the application of intensive green roofs for podium garden instead of extensive green roofs. It is considered valuable and necessary of the extensive green roofs for the buildings. This paper investigates the current practice of using extensive green roofs in Hong Kong. The constraints in applying extensive green roofs are investigated, which leads to studying the solutions for mitigating these constraints and improving the future development of the implementation.

  4. Literature Review of the Potential Energy Savings and Retention Water from Green Roofs in Comparison with Conventional Ones

    Science.gov (United States)

    Tselekis, Kyriakoulis

    2012-09-01

    The objective of this study is the comparison of green roof systems with conventional isolated and non-isolated ones in order to identify the potential energy savings of green roofs and the benefits provided in comparison with the cost of construction to the buildings. The region of interest is the Watergraafsmeer area in the city of Amsterdam. The method evaluates literature reports - mostly from 2003 to 2010 - that present the advantages of green roofs. Examples in real implementation of green roofs in USA, UK and Germany, retention of rainfall and a Life Cycle Assessment from a residential construction in Madrid will be introduced, showing the energy savings from insulation and heating/cooling that can be gained. All the reports have shown a reduction in energy costs and in runoff of water. Hence, costs and retrofitting potential completes the research. The age of buildings and the absence of insulation make green roofs an ideal alternative project for the retrofit of Watergraafsmeer.

  5. The GREENROOF module (v7.3) for modelling green roof hydrological and energetic performances within TEB

    Science.gov (United States)

    de Munck, C. S.; Lemonsu, A.; Bouzouidja, R.; Masson, V.; Claverie, R.

    2013-11-01

    The need to prepare cities for climate change adaptation requests the urban modeller community to implement sustainable adaptation strategies within their models to be tested against specific city morphologies and scenarios. Greening city roofs is part of these strategies. In this context, the GREENROOF module for TEB (town energy balance) has been developed to model the interactions between buildings and green roof systems at the scale of the city. This module, which combines the ISBA model (Interaction between Soil Biosphere and Atmosphere) and TEB, allows for one to describe an extensive green roof composed of four functional layers (vegetation - grasses or sedums; substrate; retention/drainage layers; and artificial roof layers) and to model vegetation-atmosphere fluxes of heat, water and momentum, as well as the hydrological fluxes throughout the substrate and the drainage layers, and the thermal fluxes throughout the natural and artificial layers of the green roof. TEB-GREENROOF (SURFEX v7.3) should therefore be able to represent the impact of climate forcings on the functioning of green roof vegetation and, conversely, the influence of the green roof on the local climate. An evaluation of GREENROOF is performed for a case study located in Nancy (France) which consists of an instrumented extensive green roof with sedums and substrate and drainage layers that are typical of this kind of construction. After calibration of the drainage layer hydrological characteristics, model results show good dynamics for the substrate water content and the drainage at the green roof base, with nevertheless a tendency to underestimate the water content and overestimate the drainage. This does not impact too much the green roof temperatures, which present a good agreement with observations. Nonetheless GREENROOF tends to overestimate the soil temperatures and their amplitudes, but this effect is less important in the drainage layer. These results are encouraging with regard to

  6. Research on the Cooling Effect of Green Roof%辣椒套种春大白菜高效栽培模式

    Institute of Scientific and Technical Information of China (English)

    裴承元; 林宏; 李桂莲; 李琼芬; 傅纪勇; 孟平红; 郭惊涛

    2014-01-01

    贵州是全国辣椒主产区之一,辣椒种植方式大部分为单作。为提高单位面积产量和效益,促进农民脱贫、致富奔小康,更好满足市场需求,经2年试验,探索出贵州中、低海拔地区辣椒套种春大白菜高效种植模式。经大面积套种示范,在辣椒传统单作基础上,每667 m2净增加春大白菜产值5000~6000元,取得很好的经济、社会效益。%As the development of green roof, it is more and more concerned of the research about green roof which was applied in the ecological improvement of cities environment. The paper was concentrated on the cooling effect in buildings interior and outdoor of green roof. Through field measurement and the quantitative analysis of metric data, combined with the research method abroad and at home and the unique climate of Changsha, the essay demonstrated the temperature decrease and the improvement of urban thermal environment after the green roof was carried out.

  7. Scaling of economic benefits from green roof implementation in Washington, DC.

    Science.gov (United States)

    Niu, Hao; Clark, Corrie; Zhou, Jiti; Adriaens, Peter

    2010-06-01

    Green roof technology is recognized for mitigating stormwater runoff and energy consumption. Methods to overcome the cost gap between green roofs and conventional roofs were recently quantified by incorporating air quality benefits. This study investigates the impact of scaling on these benefits at the city-wide scale using Washington, DC as a test bed because of the proposed targets in the 20-20-20 vision (20 million ft(2) by 2020) articulated by Casey Trees, a nonprofit organization. Building-specific stormwater benefits were analyzed assuming two proposed policy scenarios for stormwater fees ranging from 35 to 50% reduction for green roof implementation. Heat flux calculations were used to estimate building-specific energy savings for commercial buildings. To assess benefits at the city scale, stormwater infrastructure savings were based on operational savings and size reduction due to reduced stormwater volume generation. Scaled energy infrastructure benefits were calculated using two size reductions methods for air conditioners. Avoided carbon dioxide, nitrogen oxide (NO(x)), and sulfur dioxide emissions were based on reductions in electricity and natural gas consumption. Lastly, experimental and fugacity-based estimates were used to quantify the NO(x) uptake by green roofs, which was translated to health benefits using U.S. Environmental Protection Agency models. The results of the net present value (NPV) analysis showed that stormwater infrastructure benefits totaled $1.04 million (M), while fee-based stormwater benefits were $0.22-0.32 M/y. Energy savings were $0.87 M/y, while air conditioner resizing benefits were estimated at $0.02 to $0.04 M/y and avoided emissions benefits (based on current emission trading values) were $0.09 M-0.41 M/y. Over the lifetime of the green roof (40 years), the NPV is about 30-40% less than that of conventional roofs (not including green roof maintenance costs). These considerable benefits, in concert with current and

  8. Green Roof Evaluation: A Holistic ‘Long Life, Loose Fit, Low Energy’ Approach

    Directory of Open Access Journals (Sweden)

    Craig Langston

    2015-11-01

    Full Text Available Green roofs have potential to improve the social and environmental performance of detached housing in Australia, yet often they are overlooked due to prohibitive capital cost and a range of other perceptions that are difficult to quantify. A classic evaluation problem is invoked that must balance short and long term benefits. Using two distinct designs of the same floor area, green roof and traditional housing prototypes are analysed to determine the relative ‘breakeven’ point when long-term benefits become feasible. It is discovered that green roofs are unlikely to be viable in their own right, but when coupled with an overall design strategy of long life (durability, loose fit (adaptability and low energy (sustainability they can deliver least cost (affordability over time as well as unlock valuable social and environmental rewards. This outcome can be realised within 25% of a home’s expected design life of at least one hundred years. The results demonstrate that residential green roofs, when integrated as part of a holistic approach, can be both individually and collectively justified on key economic, social and environmental criteria, and are therefore able to claim a valuable contribution towards wider sustainable development goals.

  9. Decoupling factors affecting plant diversity and cover on extensive green roofs.

    Science.gov (United States)

    MacIvor, J Scott; Margolis, Liat; Puncher, Curtis L; Carver Matthews, Benjamin J

    2013-11-30

    Supplemental irrigation systems are often specified on green roofs to ensure plant cover and growth, both important components of green roof performance and aesthetics. Properties of the growing media environment too can alter the assemblage of plant species able to thrive. In this study we determine how plant cover, above ground biomass and species diversity are influenced by irrigation and growing media. Grass and forb vegetative cover and biomass were significantly greater in organic based growing media but there was no effect of supplemental irrigation, with two warm season grasses dominating in those treatments receiving no supplemental irrigation. On the other hand, plant diversity declined without irrigation in organic media, and having no irrigation in inorganic growing media resulted in almost a complete loss of cover. Sedum biomass was less in inorganic growing media treatments and species dominance shifted when growing media organic content increased. Our results demonstrate that supplemental irrigation is required to maintain plant diversity on an extensive green roof, but not necessarily plant cover or biomass. These results provide evidence that planting extensive green roofs with a mix of plant species can ensure the survival of some species; maintaining cover and biomass when supplemental irrigation is turned off to conserve water, or during extreme drought.

  10. GREEN ROOFS AND GREEN WALLS AS INNOVATIVE SOLUTIONS TO IMPROVE THE ENVIRONMENTAL HEALTH OF URBAN AREAS

    Directory of Open Access Journals (Sweden)

    Ilona Małuszyńska

    2014-10-01

    Full Text Available Urban areas are exposed on those originating in various sources, emissions of pollutants that pose a threat to the health of living organisms. The type of pollutant and its toxicity to organisms and mold exposure as well as the frequency of their occurrence in the environment can have a negative impact on living organisms occurring in the area. Another element negatively affecting the environmental health is a rush of individuals and communities to prosperity, which, combined with a weak nervous resistance to stressful situations contributes to the reduction of resistance to disease becoming the scourge of society as bulimia, diabetes and cancer. The tendency to increase building occurring in urban areas and the increasing number of urban dwellers in Europe as well as increasing awareness of the population about the need to protect environmental health, points to the need to seek alternative and innovative solutions for urban greenery. Investments included in that group, the green roofs and green walls, the implementation of which will increase the biologically active surface in the cities, may be an essential element of urban infrastructure that contributes to improving the quality of life of communities living in the city.

  11. Design and development of green roof substrate to improve runoff water quality: plant growth experiments and adsorption.

    Science.gov (United States)

    Vijayaraghavan, K; Raja, Franklin D

    2014-10-15

    Many studies worldwide have investigated the potential benefits achievable by transforming brown roofs of buildings to green roofs. However, little literature examined the runoff quality/sorption ability of green roofs. As the green roof substrate is the main component to alter the quality of runoff, this investigation raises the possibility of using a mixture of low-cost inorganic materials to develop a green roof substrate. The tested materials include exfoliated vermiculite, expanded perlite, crushed brick and sand along with organic component (coco-peat). Detailed physical and chemical analyses revealed that each of these materials possesses different characteristics and hence a mix of these materials was desirable to develop an optimal green roof substrate. Using factorial design, 18 different substrate mixes were prepared and detailed examination indicated that mix-12 exhibited desirable characteristics of green roof substrate with low bulk density (431 kg/m(3)), high water holding capacity (39.4%), air filled porosity (19.5%), and hydraulic conductivity (4570 mm/h). The substrate mix also provided maximum support to Portulaca grandiflora (380% total biomass increment) over one month of growth. To explore the leaching characteristics and sorption capacity of developed green roof substrate, a down-flow packed column arrangement was employed. High conductivity and total dissolved solids along with light metal ions (Na, K, Ca and Mg) were observed in the leachates during initial stages of column operation; however the concentration of ions ceased during the final stages of operation (600 min). Experiments with metal-spiked deionized water revealed that green roof substrate possess high sorption capacity towards various heavy metal ions (Al, Fe, Cr, Cu, Ni, Pb, Zn and Cd). Thus the developed growth substrate possesses desirable characteristics for green roofs along with high sorption capacity.

  12. Trends in the design, construction and operation of green roofs to improve the rainwater quality. State of the art

    Directory of Open Access Journals (Sweden)

    Jair Andrés Morales Mojica

    2017-07-01

    Full Text Available The green roofs appear as technology for the improvement water quality. This article identifies trends in the conditions of design, construction and operation of green roofs, which aim is to improve the quality of rainwater. A literature review was carried out in order to collect 45 original research papers from databases as Scopus, Science Direct, and Redalyc. From the information collected trends in increments and reductions in the concentrations of the main water quality parameters, seasons of the year with the best results, types of green roofs , types of substrate and most common components, construction trends (dimensions, inclination, Materials and layers and vegetation used in these systems have been determined. The results show that green roofs have the ability to neutralize acid rain. Extensive type roofs are the ones most commonly used, due to its characteristics of construction, functionality and low maintenance requirements.

  13. Plant establishment on unirrigated green roof modules in a subtropical climate

    Science.gov (United States)

    Dvorak, Bruce D.; Volder, Astrid

    2012-01-01

    Background and aims The application of green roof technology has become more common in the central, northwestern and eastern USA, and is now being employed across the southern USA as well. However, there is little research in the literature that evaluated plant survival on unirrigated green roofs in subtropical climates that experience frequent drought and heat stress. Here, we summarize the results of a study of plant establishment on a modular green roof in south-central Texas. Methodology Fifteen plant species were field tested in 11.4-cm-deep green roof modules on a four-storey building in College Station, Texas, with irrigation limited to the first several weeks of establishment. Climate data, plant growth and species survival were measured over three growing seasons. Principal results Four species survived growing seasons without any losses: Graptopetalum paraguayense, Malephora lutea, Manfreda maculosa and Phemeranthus calycinus. Six species experienced varying levels of mortality: Bulbine frutescens, Delosperma cooperi, Lampranthus spectabilis, Sedum kamtschaticum, Sedum mexicanum and Nassella tenuissima. Five species had no survivors: Dichondra argentea, Stemodia lanata, Myoporum parvifolium, Sedum moranense and Sedum tetractinum. Conclusions The establishment and survival of several plant species without any mortality suggests that irrigation limited to the first few weeks after planting may be an effective approach on green roofs in spite of the more challenging climatic conditions in the southern USA. Since the climate in south-central Texas had been consistently drier and warmer than normal during the study period, longer-term research on these species is recommended to expand knowledge of establishment requirements for these species under a wider range of conditions, including wetter than normal years.

  14. Portulaca grandiflora as green roof vegetation: Plant growth and phytoremediation experiments.

    Science.gov (United States)

    Vijayaraghavan, K; Arockiaraj, Jesu; Kamala-Kannan, Seralathan

    2017-06-03

    Finding appropriate rooftop vegetation may improve the quality of runoff from green roofs. Portulaca grandiflora was examined as possible vegetation for green roofs. Green roof substrate was found to have low bulk density (360.7 kg/m(3)) and high water-holding capacity (49.4%), air-filled porosity (21.1%), and hydraulic conductivity (5270 mm/hour). The optimal substrate also supported the growth of P. grandiflora with biomass multiplication of 450.3% and relative growth rate of 0.038. Phytoextraction potential of P. grandiflora was evaluated using metal-spiked green roof substrate as a function of time and spiked substrate metal concentration. It was identified that P. grandiflora accumulated all metals (Al, Cd, Cr, Cu, Fe, Ni, Pb, and Zn) from metal-spiked green roof substrate. At the end of 40 days, P. grandiflora accumulated 811 ± 26.7, 87.2 ± 3.59, 416 ± 15.8, 459 ± 15.6, 746 ± 20.9, 357 ± 18.5, 565 ± 6.8, and 596 ± 24.4 mg/kg of Al, Cd, Cr, Cu, Fe, Ni, Pb and Zn, respectively. Results also indicated that spiked substrate metal concentration strongly influenced metal accumulation property of P. grandiflora with metal uptake increased and accumulation factor decreased with increase in substrate metal concentration. P. grandiflora also showed potential to translocate all the examined metals with translocation factor greater than 1 for Al, Cu, Fe, and Zn, indicating hyperaccumulation property.

  15. Linking Rainfall Variability and Carbon Cycling in a Green Roof Ecosystem

    Science.gov (United States)

    Potts, D. L.; Warren, R. J., II; Ivancic, T. A.

    2015-12-01

    Whereas green roof hydrology is well-studied, these systems present a novel opportunity to examine plant-mediated linkages between rainfall and carbon cycling. For example, green roofs experience dramatic fluctuations in soil moisture because they have limited soil water holding capacity and high rates of evaporation. Stonecrop (Sedum spp.) is widely planted in green roofs and its traits reflect an overall strategy of water conservation. In addition to succulent leaves and a slow growth rate, several stonecrop species possess inducible CAM photosynthesis. We made continuous measurements of ecosystem CO2 exchange, soil temperature (T), and volumetric soil moisture (θ) using a chamber-based automated monitoring system installed on a 3-year old green roof located in Buffalo, New York. Concurrent measurements of net ecosystem CO2 exchange (NEE) and ecosystem respiration (Re) allowed us to estimate gross ecosystem CO2 exchange (GEE). We predicted that CAM photosynthesis by stonecrop would be induced by high T and low θ and would manifest at the ecosystem scale by a reductions in both reduced midday CO2 uptake associated with stomatal closure and nighttime net CO2 efflux as CAM-driven assimilation offset respiratory losses. Not surprisingly, increased T and decreased θ negatively influenced GEE while Re increased in response to increased T and θ. During a period of unusually hot, dry conditions the responses of GEE and Re were reflected in a decline in daytime NEE. However, this decline in NEE was not associated with a similar reduction in nighttime Re suggesting that these conditions were insufficient to induce CAM photosynthesis. Future ecohydrological investigations of green roofs may provide new insights into how rainfall variability interacts with plant traits, community diversity, and edaphic factors to shape ecosystem function.

  16. The GREENROOF module (v7.3 for modelling green roof hydrological and energetic performances within TEB

    Directory of Open Access Journals (Sweden)

    C. S. de Munck

    2013-02-01

    Full Text Available The need to prepare cities for climate change adaptation requests the urban modeller community to implement within their models sustainable adaptation strategies to be tested against specific city morphologies and scenarios. Greening city roofs is part of these strategies. In this context, a GREENROOF module for TEB (Town Energy Balance has been developed to model the interactions between buildings and green roof systems at the scale of the city. This module allows one to describe an extensive green roof composed of four functional layers (vegetation – grasses or sedums, substrate, retention/drainage layers and artificial roof layers and to model vegetation-atmosphere fluxes of heat, water and momentum, as well as the hydrological and thermal fluxes throughout the substrate and the drainage layers, and the thermal coupling with the structural building envelope. TEB-GREENROOF (v7.3 is therefore able to represent the impact of climate forcings on the functioning of the green roof vegetation and, conversely, the influence of the green roof on the local climate. A calibration exercise to adjust the model to the peculiar hydrological characteristics of the substrates and drainage layers commonly found on green roofs is performed for a case study located in Nancy (France which consists of an extensive green roof with sedums. Model results for the optimum hydrological calibration show a good dynamics for the substrate water content which is nevertheless under-estimated but without impacting too much the green roof temperatures since they present a good agreement with observations. These results are encouraging with regard to modelling the impact of green roofs on thermal indoor comfort and energy consumption at the scale of cities, for which GREENROOF will be running with the building energy version of TEB, TEB-BEM. Moreover, the green roof studied for GREENROOF evaluation being a city-widespread type of extensive green roof, the hydrological

  17. Retrofitting Housing with Lightweight Green Roof Technology in Sydney, Australia, and Rio de Janeiro, Brazil

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    Sara Wilkinson

    2015-01-01

    Full Text Available The built environment contributes around half of total greenhouse gas emissions and with 87% of residential buildings that we will have by 2050 already built, it is vital to adopt sustainable retrofitting practices. The question is: what are the viable solutions? One answer may be green roof retrofitting. The environmental benefits include reduced operational carbon emissions, reduced urban heat island effect, increased bio-diversity, housing temperature attenuation and reduced stormwater run-off. The economic benefits are the reduced maintenance costs and lower running costs. The social gain is the creation of spaces where people have access to green areas. However, the barriers to retrofitting include the perceptions of structural adequacy, the risk of water damage, high installation and maintenance costs, as well as access and security issues. Many Australian and Brazilian residential buildings have metal sheet roofs, a lightweight material with poor thermal performance. During the summer, temperatures in Sydney and Rio de Janeiro reach 45 degrees Celsius, and in both cities, rainfall patterns are changing, with more intense downpours. Furthermore, many residential buildings are leased, and currently, tenants are restricted by the modifications that they can perform to reduce running costs and carbon emissions. This research reports on an experiment on two small-scale metal roofs in Sydney and Rio de Janeiro to assess the thermal performance of portable small-scale modules. The findings are that considerable variation in temperature was found in both countries, indicating that green roof retrofitting could lower the cooling energy demand considerably.

  18. Stormwater runoff mitigation and nutrient leaching from a green roof designed to attract native pollinating insects

    Science.gov (United States)

    Fogarty, S.; Grogan, D. S.; Hale, S. R.

    2013-12-01

    A green roof is typically installed for one of two reasons: to mitigate the 'urban heat island' effect, reducing ambient temperatures and creating energy savings, or to reduce both the quantity and intensity of stormwater runoff, which is a major cause of river erosion and eutrophication. The study of green roofs in the United States has focused on commercial systems that use a proprietary expanded shale or clay substrate, along with succulent desert plants (mainly Sedum species). The green roof has the potential not only to provide thermal insulation and reduce storm runoff, but also to reclaim some of the natural habitat that has been lost to the built environment. Of special importance is the loss of habitat for pollinating insects, particularly native bees, which have been in decline for at least two decades. These pollinators are essential for crop production and for the reproduction of at least 65% of wild plants globally. Our study involves the installation of a small (4ft by 4ft), self-designed green roof system built with readily available components from a hardware store. The garden will be filled with a soilless potting mix, combined with 15% compost, and planted with grasses and wildflowers native to the Seacoast, New Hampshire region. Some of the plant species are used by bees for nesting materials, while others provide food in the form of nectar, pollen, and seeds for bees, butterflies, hummingbirds, and granivorous birds. We monitor precipitation on the roof and runoff from the garden on a per storm basis, and test grab samples of runoff for dissolved organic nitrogen and phosphorous. Runoff and nutrient concentration results are compared to a non-vegetated roof surface, and a proprietary Green Grid green roof system. This project is designed to address three main questions of interest: 1) Can these native plant species, which potentially provide greater ecosystem services than Sedum spp. in the form of food and habitat, survive in the conditions on

  19. The Perception of Malaysian Architects towards the Implementation of Green Roofs: A Review of Practices, Methodologies and Future Research

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    Zahir M.H. Md.

    2014-01-01

    Full Text Available The implementation of green roofs or vegetated roof as a sustainable tool to mitigate the Urban Heat Island effect is relatively new in Malaysia. Although it has not been tested on an urban scale, many research findings have indicated that green roofs can contribute towards enhancing the environmental and aesthetical quality of the built environment. It was hypothesized that the low application of green roofs in the Malaysian construction industry is due to the lack of awareness, understanding and experience in its benefits especially among building practitioners. As a result, this research was initiated to determine the perception and understanding of Malaysian architects in green roofs implementation issues, as well as to identify their level of acceptance and readiness. This paper reviews practices and different research approaches in understanding the factors that influence architect’s perception towards the implementation of green roofs in the Malaysian construction industry. Architects were chosen as the only respondents due to their intensive involvement in the conceptualisation, planning, design and construction stage of a built environment project. Extensive literature review was conducted to explore past experiences in green roof implementation and to develop the theoretical framework for this research.

  20. Quality and seasonal variation of rainwater harvested from concrete, asphalt, ceramic tile and green roofs in Chongqing, China.

    Science.gov (United States)

    Zhang, Qianqian; Wang, Xiaoke; Hou, Peiqiang; Wan, Wuxing; Li, Ruida; Ren, Yufen; Ouyang, Zhiyun

    2014-01-01

    There is an urgent requirement to examine the quality of harvested rainwater for potable and non-potable purposes, based on the type of roofing material. In this study, we examined the effect on the quality of harvested rainwater of conventional roofing materials (concrete, asphalt and ceramic tile roofs) compared with alternative roofing materials (green roof). The results showed that the ceramic tile roof was the most suitable for rainwater-harvesting applications because of the lower concentrations of leachable pollutants. However, in this study, the green roof was not suitable for rainwater harvesting applications. In addition, seasonal trends in water quality parameters showed that pollutants in roof runoff in summer and autumn were lower than those in winter and spring. This study revealed that the quality of harvested rainwater was significantly affected by the roofing material; therefore, local government and urban planners should develop stricter testing programs and produce more weathering resistant roofing materials to allow the harvesting of rainwater for domestic and public uses.

  1. Integrated Modelling and Performance Analysis of Green Roof Technologies in Urban Environments

    Science.gov (United States)

    Liu, Xi; Mijic, Ana; Maksimovic, Cedo

    2014-05-01

    As a result of the changing global climate and increase in urbanisation, the behaviour of the urban environment has been significantly altered, causing an increase in both the frequency of extreme weather events, such as flooding and drought, and also the associated costs. Moreover, uncontrolled or inadequately planned urbanisation can exacerbate the damage. The Blue-Green Dream (BGD) project therefore develops a series of components for urban areas that link urban vegetated areas (green infrastructure) with existing urban water (blue) systems, which will enhance the synergy of urban blue and green systems and provide effective, multifunctional BGD solutions to support urban adaptation to future climatic changes. Coupled with new urban water management technologies and engineering, multifunctional benefits can be gained. Some of the technologies associated with BGD solutions include green roofs, swales that might deal with runoff more effectively and urban river restoration that can produce benefits similar to those produced from sustainable urban drainage systems (SUDS). For effective implementation of these technologies, however, appropriate tools and methodologies for designing and modelling BGD solutions are required to be embedded within urban drainage models. Although several software packages are available for modelling urban drainage, the way in which green roofs and other BGD solutions are integrated into these models is not yet fully developed and documented. This study develops a physically based mass and energy balance model to monitor, test and quantitatively evaluate green roof technology for integrated BGD solutions. The assessment of environmental benefits will be limited to three aspects: (1) reduction of the total runoff volume, (2) delay in the initiation of runoff, and (3) reduction of building energy consumption, rather than water quality, visual, social or economic impacts. This physically based model represents water and heat dynamics in a

  2. [Influence of the substrate composition in extensive green roof on the effluent quality].

    Science.gov (United States)

    Chen, Yu-Lin; Li, Tian; Gu, Jun-Qing

    2014-11-01

    By monitoring the effluent quality from different green roof assemblies during several artificial rain events, the main pollutant characteristics and the influence of substrate composition in extensive green roof on the effluent quality were studied. Results showed that the main pollutants in the effluent were N, P and COD; with the increase of cumulative rain, the concentrations of pollutants in the effluent decreased, which had obvious leaching effect; The average concentrations of heavy metals in the early effluent from all assemblies reached drinking water standard, including the assemblies using crushed bricks; When garden soil and compost were used as organic matter, the assemblies had serious leaching of nutrient substance. After the accumulated rainfall reached 150 mm, the TN, TP and COD concentrations of effluent were 2.93, 0.73 and 78 mg x L(-1), respectively, which exceeded the Surface water V class limit. By means of application of the Water Treatment Residual, the leaching of TP from green planting soil was decreased by about 60%. The inorganic compound soil had better effluent quality, however we also need to judge whether the substrate could be applied in extensive green roof or not, by analyzing its ability of water quantity reduction and the plant growth situation.

  3. Integrated Green Roofs System and its Role of Achieving Sustainability in Residential Buildings in Urban Area in Athens, Greece and Famagusta, North Cyprus

    Directory of Open Access Journals (Sweden)

    Seyed Mehran shahidipour

    2014-06-01

    Full Text Available In this paper, the characteristics and importance of the green roof in urban area would investigate in some residential buildings in Athens, Greece and then, some strategies give to integrate green roof in residential buildings in Famagusta, north Cyprus due to the importance of energy saving and thermal comfort in residential buildings. These days, sustainable architecture is spreading around the world. Therefore, Sustainable architecture has important role in design buildings and urban design due to high amount of energy use and global warming around the world. There are different methods in sustainable design and one of them that has significant role is design green roof. Green roof integrated to the roof of the buildings to provide the suitable indoor temperature without spending high amount of budget. The methodology is qualitative type that trough the literature review and survey would be understood the importance and role of the green roof in both architecture and urban area. There are many significant architects like Wright that they understood how greenery would improve the function of the building in terms of provide thermal comfort and indoor temperature for the residences, and green roof as well. In Famagusta, there is not any green roof however, the design and integrating of green roof is inexpensive. Green roof should design properly depend on the characteristic of the climate of every place so, the location, temperature, and humidity, location, and wind have influence on the design of the green roof.

  4. Direct and Indirect Impacts of Vegetation on Building Comfort: A Comparative Study of Lawns, Green Walls and Green Roofs

    Directory of Open Access Journals (Sweden)

    Laurent Malys

    2016-01-01

    Full Text Available Following development and validation of the SOLENE-microclimat tool, the underlying model was used to compare the impacts of various “greening strategies” on buildings’ summer energy consumption and indoor comfort. This study distinguishes between direct and indirect impacts by successively implementing the test strategies on both the studied building and surrounding ones; it also considers insulated vs. non-insulated buildings. Findings indicate that green walls have a direct effect on indoor comfort throughout the entire building, whereas the effect of green roofs is apparently primarily confined to the upper floor. Moreover, the indirect effect of a green wall is greater, mainly due to the drop in infrared emissions resulting from a lower surface temperature. It has also been proven that the indirect effects of green walls and surrounding lawns can help reduce the loads acting on a non-insulated building.

  5. Green Roof Research through EPA's Regional Applied Research Effort

    Science.gov (United States)

    ABSTRACT The U.S. Environmental Protection Agency’s (EPA) Regional Applied Research Effort (RARE) allows the Regions of the EPA to choose research projects to be performed in partnership with EPA’s Office of Research and Development (ORD). Over the last decade, several green roo...

  6. Optimal Adoption of Green Roofs: Hydrology and Public Finance Applications

    Science.gov (United States)

    2008-03-01

    green products increase worldwide on a daily basis and currently account for 9% of all new-product launches in the United States ( Marmor , 2007...Consumption Survey, Published 2003 by the Energy Information Administration under the United States Department of Energy Marmor , Jessica. 2007

  7. A field study to evaluate the impact of different factors on the nutrient pollutant concentrations in green roof runoff.

    Science.gov (United States)

    Wang, Xiaochen; Zhao, Xinhua; Peng, Chenrui; Zhang, Xinbo; Wang, Jianghai

    2013-01-01

    The objectives of this study are to investigate the impact of different factors on the nutrient pollutant concentrations in green roof runoff and to provide reference data for the engineering design of dual substrate layer green roofs. The data were collected from eight different trays under three kinds of artificial rains. The results showed that except for total phosphorus, dual substrate layer green roofs behaved as a sink for most of the nutrient pollutants (significant at p < 0.05), and the first-flush effect did not occur during the 27 simulated rain events. The results also revealed that the concentration of these nutrient pollutants in the runoff strongly depended on the features of the nutrient substrates used in the green roof and the depth of the adsorption substrates. Compared with the influence of the substrates, the influence of the plant density and drainage systems was small.

  8. High resolution rainfall – runoff measurement setup for green roof experiments in a tropical environment

    Directory of Open Access Journals (Sweden)

    T. Vergroesen

    2010-12-01

    Full Text Available This article describes the measurement setup that is used for green roof experiments in a tropical environment, the required data treatment to obtain reliable values of rainfall, runoff and evapotranspiration, and how to deal with external disturbances that can influence the experiment results. High resolution rainfall runoff measurements to identify, understand and properly model the relevant runoff processes in a green roof require both tailored equipment and data treatment. A tipping bucket rain gauge is calibrated for and installed to measure minute based rain intensities. A runoff measuring setup is developed that can accurately quantify the runoff up to 6 l/min, and has a high resolution in both time and volume. Two different measuring setups are used to verify the evapotranspiration that is derived from the rainfall and runoff measurements.

  9. Survival of two introduced plant growth promoting micro-organisms in green roof soil in southern Finland

    OpenAIRE

    Xie, Long

    2014-01-01

    Glomus intraradices and Bacillus amyloliquefaciens are two commercially used plant growth promoting micro-organisms. They associate with plant roots to facilitate host plants to absorb nutrients, induce resistance against pathogens and pests, and regulate growth through phytohormones. Growth conditions for plants on green roofs are often unfavorable. In order to test whether growth and development of green roof plants could be enhanced via improving the microbial interface, G. intraradices an...

  10. A study on the usage and perceptions of office building occupants to green roofs in Hong Kong

    OpenAIRE

    2014-01-01

    As Hong Kong is famous for its image of leading international financial metropolis, many high-rise office buildings are confined inside some developed commercial districts of Hong Kong. A place for provision of greenery in such districts seems impracticable. However, greenery can exist in forms of green roof onto office buildings, it seems a practical way to embellish this concrete city. Academic studies from other countries have proven that having green roof onto buildings is able to bri...

  11. ANALYSIS OF WATER RELATIONS OF SUBSTRATES USED IN GREEN ROOF SYSTEMS

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    Anna Baryła

    2014-10-01

    Full Text Available Green roofs, as the restoration of biologically active area, are fairly common and effective method of storm water management in urban areas. Depend on the design of the green roof and the type of substrate, they are able to retain 50–90% of rainwater. The aim of the study was to determine the physicochemical properties of two substrates used in the construction of green roofs (intensive and extensive. Water retention of substrates was compared to water retention of substrates undelined with the drainage layer made from crushed autoclaved aerated concrete. In the experiment, which uses drainage layer, higher drying the top layer of the substrate was observed, which may be related to high water absorption drainage material. The effluent from the substrate using aerated concrete as a drainage layer amounted to an average of 22–51% of the volume of water supplied to the extensive substrate, whereas 19–46% of the volume of water supplied to the intensive substrate. The effluent from the substrate without the drainage layer amounted 40-48% of the volume of water supplied.

  12. Soil-roots Strength Performance of Extensive Green Roof by Using Axonopus Compressus

    Science.gov (United States)

    Yusoff, N. A.; Ramli, M. N.; Chik, T. N. T.; Ahmad, H.; Abdullah, M. F.; Kasmin, H.; Embong, Z.

    2016-07-01

    Green roof technology has been proven to provide potential environmental benefits including improved building thermal performance, removal of air pollution and reduced storm water runoff. Installation of green roof also involved soil element usage as a plant growth medium which creates several interactions between both strands. This study was carried out to investigate the soil-roots strength performance of green roof at different construction period up to 4 months. Axonopus compressus (pearl grass) was planted in a ExE test plot with a designated suitable soil medium. Direct shear test was conducted for each plot to determine the soil shear strength according to different construction period. In addition, some basic geotechnical testing also been carried out. The results showed that the shear strength of soil sample increased over different construction period of 1st, 2nd, 3rd and 4th month with average result 3.81 kPa, 5.55 kPa, 6.05 kPa and 6.48 kPa respectively. Shear strength of rooted soil samples was higher than the soil samples without roots (control sample). In conclusion, increment of soil-roots shear strength was due to root growth over the time. The soil-roots shear strength development of Axonopus compressus can be expressed in a linear equation as: y = 0.851x + 3.345, where y = shear stress and x = time.

  13. Lightweight Aggregate Made from Dredged Material in Green Roof Construction for Stormwater Management

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    Rui Liu

    2016-07-01

    Full Text Available More than 1.15 million cubic meters (1.5 million cubic yards of sediment require annual removal from harbors and ports along Ohio’s Lake Erie coast. Disposing of these materials into landfills depletes land resources, while open water placement of these materials deteriorates water quality. There are more than 14,000 acres of revitalizing brownfields in Cleveland, U.S., many containing up to 90% impervious surface, which does not allow “infiltration” based stormwater practices required by contemporary site-based stormwater regulation. This study investigates the potential of sintering the dredged material from the Harbor of Cleveland in Lake Erie to produce lightweight aggregate (LWA, and apply the LWA to green roof construction. Chemical and thermal analyses revealed the sintered material can serve for LWA production when preheated at 550 °C and sintered at a higher temperature. Through dewatering, drying, sieving, pellet making, preheating, and sintering with varying temperatures (900–1100 °C, LWAs with porous microstructures are produced with specific gravities ranging from 1.46 to 1.74, and water absorption capacities ranging from 11% to 23%. The water absorption capacity of the aggregate decreases as sintering temperature increases. The LWA was incorporated into the growing media of a green roof plot, which has higher water retention capacity than the conventional green roof system.

  14. Green roof soil system affected by soil structural changes: A project initiation

    Science.gov (United States)

    Jelínková, Vladimíra; Dohnal, Michal; Šácha, Jan; Šebestová, Jana; Sněhota, Michal

    2014-05-01

    Anthropogenic soil systems and structures such as green roofs, permeable or grassed pavements comprise appreciable part of the urban watersheds and are considered to be beneficial regarding to numerous aspects (e.g. carbon dioxide cycle, microclimate, reducing solar absorbance and storm water). Expected performance of these systems is significantly affected by water and heat regimes that are primarily defined by technology and materials used for system construction, local climate condition, amount of precipitation, the orientation and type of the vegetation cover. The benefits and potencies of anthropogenic soil systems could be considerably threatened in case when exposed to structural changes of thin top soil layer in time. Extensive green roof together with experimental green roof segment was established and advanced automated monitoring system of micrometeorological variables was set-up at the experimental site of University Centre for Energy Efficient Buildings as an interdisciplinary research facility of the Czech Technical University in Prague. The key objectives of the project are (i) to characterize hydraulic and thermal properties of soil substrate studied, (ii) to establish seasonal dynamics of water and heat in selected soil systems from continuous monitoring of relevant variables, (iii) to detect structural changes with the use of X-ray Computed Tomography, (iv) to identify with the help of numerical modeling and acquired datasets how water and heat dynamics in anthropogenic soil systems are affected by soil structural changes. Achievements of the objectives will advance understanding of the anthropogenic soil systems behavior in conurbations with the temperate climate.

  15. Plant performance on Mediterranean green roofs: interaction of species-specific hydraulic strategies and substrate water relations.

    Science.gov (United States)

    Raimondo, Fabio; Trifilò, Patrizia; Lo Gullo, Maria A; Andri, Sergio; Savi, Tadeja; Nardini, Andrea

    2015-01-20

    Recent studies have highlighted the ecological, economic and social benefits assured by green roof technology to urban areas. However, green roofs are very hostile environments for plant growth because of shallow substrate depths, high temperatures and irradiance and wind exposure. This study provides experimental evidence for the importance of accurate selection of plant species and substrates for implementing green roofs in hot and arid regions, like the Mediterranean area. Experiments were performed on two shrub species (Arbutus unedo L. and Salvia officinalis L.) grown in green roof experimental modules with two substrates slightly differing in their water retention properties, as derived from moisture release curves. Physiological measurements were performed on both well-watered and drought-stressed plants. Gas exchange, leaf and xylem water potential and also plant hydraulic conductance were measured at different time intervals following the last irrigation. The substrate type significantly affected water status. Arbutus unedo and S. officinalis showed different hydraulic responses to drought stress, with the former species being substantially isohydric and the latter one anisohydric. Both A. unedo and S. officinalis were found to be suitable species for green roofs in the Mediterranean area. However, our data suggest that appropriate choice of substrate is key to the success of green roof installations in arid environments, especially if anisohydric species are employed.

  16. Seasonal and Diurnal Thermal Performance of a Subtropical Extensive Green Roof: The Impacts of Background Weather Parameters

    Directory of Open Access Journals (Sweden)

    Lilliana L. H. Peng

    2015-08-01

    Full Text Available Most studies explored green-roof thermal effects on a few hot summer days based on short-term monitoring data. Few studies investigated the seasonal and diurnal patterns of thermal performance and associated weather effects. This research aims to address the following two questions: (1 how green-roof thermal performance varies with different season and time; and (2 to what extent can thermal performance be predicted by background weather parameters? A retrofitted extensive green roof was established on the top of a railway station in subtropical Hong Kong. Monitoring data covering a two-year period, one year before roof greening and one year after, were collected and analyzed. Results indicated notable seasonal and diurnal patterns of green-roof thermal performance. It exhibited cooling effects in spring, summer and fall, but warming effects in winter. The cooling effects were more pronounced in summer than spring and fall, on sunny days than rainy and cloudy days, and in nighttime than daytime. Air temperature, relative humidity, wind speed, solar radiation, and soil moisture could explain 83.6%–86% of the thermal effects’ variation. The multiple-regression models based on the five weather variables established in this study provide an uncomplicated and direct approach to predict the thermal performance of similar extensive green roofs in subtropical areas.

  17. Thin soil layer of green roof systems studied by X-Ray CT

    Science.gov (United States)

    Šácha, Jan; Jelínková, Vladimíra; Dohnal, Michal

    2016-04-01

    The popular non-invasive visualization technique of X-ray computed tomography (CT) has been used for 3D examination of thin soil layer of vegetated roof systems. The two categories of anthropogenic soils, usually used for green roof systems, were scanned during the first months after green roof system construction. First was represented by stripped topsoil with admixed crushed bricks and was well graded in terms of particle size distribution. The other category represented a commercial lightweight technogenic substrate. The undisturbed soil samples of total volume of 62.8 ccm were studied be means of X-ray Computed Tomography using X-ray Inspection System GE Phoenix Nanomex 180T with resulting spatial resolution about 57 μm in all directions. For both soil categories visible macroporosity, connectivity (described by the Euler characteristic), dimensionless connectivity and critical cross section of pore network were determined. Moreover, the temporal structural changes of studied soils were discussed together with heat and water regime of the green roof system. The analysis of CT images of anthropogenic soils was problematic due to the different X-ray attenuation of individual constituents. The correct determination of the threshold image intensity differentiating the soil constituents from the air phase had substantial importance for soil pore network analyses. However, X-ray CT derived macroporosity profiles reveal significant temporal changes notably in the soil comprised the stripped topsoil with admixed crushed bricks. The results implies that the technogenic substrate is structurally more stable over time compared to the stripped topsoil. The research was realized as a part of the University Centre for Energy Efficient Buildings supported by the EU and with financial support from the Czech Science Foundation under project number 14-10455P.

  18. Differential substrate subsidence of the EnviHUT project pitched extensive green roof

    Directory of Open Access Journals (Sweden)

    Nečadová Klára

    2017-01-01

    Full Text Available In primary phase of testing building physical characteristics of the EnviHUT project extensive and semi-intensive roofs with 30° inclination occurred exceptional substrate subsidence. An extensive testing field with retaining geocell-system evinced differential subsidence of individual sectors after six months. Measured subsidence of installed substrate reached 40 % subsidence compared to originally designed height (intended layer thickness. Subsequent deformation of geocell-system additionally caused partial slide of substrate to drip edge area. These slides also influenced initial development of stonecrop plants on its surface. Except functional shortages the aesthetical function of the whole construction is influenced by the mentioned problem. The stated paper solves mentioned issues in view of installation method optimization, selection and modification of used roof substrate and in view of modification of geometric and building installed elements retaining system arrangement. Careful adjustment of roof system geometry and enrichment of original substrate fraction allow full functionality from pitched extensive green roof setting up. The modification scheme and its substantiation is a part of this technical study output.

  19. Combating the Urban Heat Island Effect: Results from a Long-Term Monitoring Study on Urban Green, White, and Black Roofs in New York City

    Science.gov (United States)

    Gaffin, S. R.; Kong, A. Y.; Hartung, E.; Hsu, B.; Roditi, A.; Rosenzweig, C.

    2011-12-01

    Urban heat island mitigation strategies include increasing urban vegetation and increasing the albedo of impervious surfaces. Vegetated "green" roofs can provide benefits to stormwater management, water quality, energy cost efficiency, and biodiversity in cities, but the body of research on green roofs in the US is not large and cities in the US have been slow to adopt green roofs. On the other hand, "high-albedo" white roofs have been applied more widely through projects such as New York City Cool Roofs. There are several major issues (e.g., albedo decline, product differences, and long-term temperature controls) about green and white roof performance versus typical black roofs with respect to urban heat island mitigation that have yet to be fully addressed. Here, we present data from an on-going, long-term study in New York City in which pilot, urban albedo enhancement and vegetation effects have been monitored at the building-scale since 2007. Although the urban heat island effect can be detected throughout the year, our objective for this paper was to compare green roof vegetation with those of the high-albedo roofs for their ability to reduce the electricity demand for cooling in the summer. Using energy balance methodology across our sites (three), we found that green and white roof membrane temperature peaks are on average 60°F (33°C) and 30° F (17°C), respectively, cooler than black roof temperature peaks, and that these alternative surfaces significantly reduce thermal stress to roof membranes. Interestingly, we found that industrial white membranes [thermoplastic polyolefin (TPO) and ethylene propylene diene monomer (EPDM)] stay cleaner longer, thereby, maintaining the high-albedo benefits longer than the painted roofs, which tend to lose their albedo properties rapidly. Results thus far suggest that more long-term research comparing the albedo and cooling benefits of green and white roofs to black roofs is necessary to understand temporal changes to

  20. Green Roof Concepts as a Passive Cooling Approach in Tropical Climate- An Overview

    Directory of Open Access Journals (Sweden)

    Kamarulzaman Noorazlina

    2014-01-01

    Full Text Available Nowadays, increasing of energy consumption due to global warming issues such as heat island effects has attracted the awareness of researchers, architects, engineers, property developers, and authorities to the crucial of green construction or sustainable development concept. Energy efficiency has been identified as a key consideration in discussions of this concept. In term of energy, Malaysia ranked 33rd in the list of global electricity consumption and 25th in the list of man-made carbon dioxide emissions. If energy consumption continues to increase at its current rate, domestic petroleum reserve in Peninsular Malaysia is predicted to be depleted by 2014 and Sarawak by 2020 [1]. As responding to the increasing of energy consumption, the demand of green roof technology as passive cooling technique has been recognized worldwide. Generally, by greening the rooftops in urban area, the impact on the urban climate and microclimate as well as on the indoor climate of buildings beneath them will be reduced. Therefore, this paper systematically review the concepts of green roof to give a basic understanding as global. Discussion on the benefits of this concept and its components among topic will be discussed.

  1. A Mathematical Model of the Rainwater Flows in a Green Roof

    CERN Document Server

    Adley, Catherine; Fay, Gemma; Hewitt, Ian; Lacey, Andrew; Mellgren, Niklas; Robinson, Marguerite; Vynnycky, Michael

    2016-01-01

    A model is presented for the gravity-driven flow of rainwater descending through the soil layer of a green roof, treated as a porous medium on a flat permeable surface representing an efficient drainage layer. A fully saturated zone is shown to occur. It is typically a thin layer, relative to the total soil thickness, and lies at the bottom of the soil layer. This provides a bottom boundary condition for the partially saturated upper zone. It is shown that after the onset of rainfall, well-defined fronts of water can descend through the soil layer. Also the rainwater flow is relatively quick compared with the moisture uptake by the roots of the plants in the roof. In separate models the exchanges of water are described between the (smaller-scale) porous granules of soil, the roots and the rainwater in the inter-granule pores.

  2. Hydrological performance of an extensive green roof: a case study from the central Europe (Bustehrad, Czech Republic)

    Science.gov (United States)

    Tománková, Klára; Sněhota, Michal; Jelínková, Vladimíra

    2016-04-01

    Extensive green roofs with a thin growing medium require minimal maintenance, and in general no irrigation. The proper functioning of such systems rests with their structural constituents, especially with the substrate used for planting. An extensive green roof with poorly developed vegetation and with a soil layer of a maximum thickness of 5 cm mixed with local stripped topsoil with crushed bricks and green waste was studied with respect to the hydrological behavior. The substrate classified as loam comprises a significant proportion of very fine particles and thus it is prone to clogging up of soil pores and forming of fissures on the surface. The green roof studied is well equipped for measuring meteorological data including air temperature, wind speed and direction, net radiation, relative humidity, and rainfall intensity. The meteorological information on the site is completed by soil temperature measurement. The 12 m long transect is equipped with eight time domain reflectometry probes (TDR) to monitor soil water content. Soil physical properties (bulk density, porosity, grain size distribution) and soil hydraulic characteristics (soil water retention curve) were obtained. The numerical modeling of transient soil water movement in the green roof substrate was performed using a two-dimensional model based on the Richards' equation. Results were compared with the soil water content data acquired. Six alternative scenarios were formulated to discuss possible improvement of green roof functioning and four selected scenarios were simulated. The study helped us to improve our understanding of the flow processes through the green roof soil system under study. The alternative scenario simulations allowed hydrological assessment of roof construction amendments. The research was realized as a part of the University Centre for Energy Efficient Buildings supported by the EU and with financial support from the Czech Science Foundation under project number 14-10455P.

  3. Discussion on Design of Planting Green on Roofs%屋顶绿化设计探讨

    Institute of Scientific and Technical Information of China (English)

    王静

    2014-01-01

    从实际工作出发,就目前比较热门的屋顶绿化做了一些介绍,尤其是屋顶绿化的种植形式、类型以及屋顶绿化应该注意的问题,提出了屋顶绿化植物的选择方法和种植设计要点,为绿化工作者提供了参考。%Starting from the actual work, some items which should be noted especially in the form of planting green roofs were introduced, especially green roof types and other cases. This article also put forward the roof greening plant selection methods and planting design points, to provide some references for green workers.

  4. Including A-Priori Assessment of Actual Evapotranspiration for Green Roof Daily Scale Hydrological Modelling

    Directory of Open Access Journals (Sweden)

    Mirka Mobilia

    2017-01-01

    Full Text Available In the last decades, there has been a widespread implementation of Green Infrastructures worldwide. Among these, green roofs appear to be particularly flexible sustainable drainage facilities. To predict their effectiveness for planning purposes, a tool is required that provides information as a function of local meteorological variables. Thus, a relatively simple daily scale, one-dimensional water balance approach has been proposed. The crucial evapotranspiration process, usually considered as a water balance dependent variable, is replaced here by empirical relationships providing an a-priori assessment of soil water losses through actual evapotranspiration. The modelling scheme, which under some simplification can be used without a calibration process, has been applied to experimental runoff data monitored at a green roof located near Bernkastel (Germany, between April 2005 and December 2006. Two different empirical relationships have been used to model actual evapotranspiration, considering a water availability limited and an energy limited scheme. Model errors quantification, ranging from 2% to 40% on the long-term scale and from 1% to 36% at the event scale, appear strongly related to the particularly considered relationship.

  5. A Mass Balance Model for Designing Green Roof Systems that Incorporate a Cistern for Re-Use

    Directory of Open Access Journals (Sweden)

    Manoj Chopra

    2012-11-01

    Full Text Available Green roofs, which have been used for several decades in many parts of the world, offer a unique and sustainable approach to stormwater management. Within this paper, evidence is presented on water retention for an irrigated green roof system. The presented green roof design results in a water retention volume on site. A first principle mass balance computer model is introduced to assist with the design of these green roof systems which incorporate a cistern to capture and reuse runoff waters for irrigation of the green roof. The model is used to estimate yearly stormwater retention volume for different cistern storage volumes. Additionally, the Blaney and Criddle equation is evaluated for estimation of monthly evapotranspiration rates for irrigated systems and incorporated into the model. This is done so evapotranspiration rates can be calculated for regions where historical data does not exist, allowing the model to be used anywhere historical weather data are available. This model is developed and discussed within this paper as well as compared to experimental results.

  6. Hydric Attenuation and Hydrological Benefits for Implementing Productive Green Roof in Soacha, Colombia

    OpenAIRE

    Oviedo Escobar, Nicolas; Grupo de investigación Ciencia e Ingeniería del Agua y el Ambiente, Facultad de Ingeniería, Pontificia Universidad Javeriana, Bogotá; Torres, Andres; Grupo de investigación Ciencia e Ingeniería del Agua y el Ambiente, Facultad de Ingeniería, Pontificia Universidad Javeriana, Bogotá

    2014-01-01

    In this study the hydric attenuation of a productive green roof was assessed by using three indicators: lag-time, runoff coefficient and water volume retained. Two types of plants – an herbaceous (Lactuca sativa) and a Cruciferae (Raphanus sativus) – were considered and eight rain events were monitored for four houses in La Isla neighborhood, Soacha (Colombia) (4° 34’ 22.3”, 74° 10’ 53.5”, 2701 meters above sea level). Maximum lag-times and volumetric percentage retention and minimum equivale...

  7. 一组绿色屋面动态%Developments in green roofs

    Institute of Scientific and Technical Information of China (English)

    肖石

    2006-01-01

    Green Roof Infrastructure Monitor》为配合今年5月在美国波士顿召开的第4届国际绿色屋面会议.集中刊登了将在会议上发表的一些论文简介和有关绿色屋面的消息。本刊摘译了其中部分内容.刊登如下。

  8. 绿色建筑的屋顶设计%The Roof Design of Green Building

    Institute of Scientific and Technical Information of China (English)

    2013-01-01

      我们的一切能量最初都来自于太阳和天空,能量也会也会从天上反馈回来。所以屋顶,将会是我们绿色建筑设计中与自然互动最大的一块区域。%Al the energy we original y comes from the sun and sky, energy wil also come back from heaven. So the roof wil be the largest regional interaction with nature in our green building design.

  9. Effects of Wastes from the Brewing Industry in Lightweight Aggregates Manufactured with Clay for Green Roofs

    Directory of Open Access Journals (Sweden)

    Romina D. Farías

    2017-05-01

    Full Text Available This study investigates the effects of sieved wastes generated from the brewing industry on lightweight aggregates manufactured with clay. Sludge from a wastewater treatment plant, bagasse and diatomaceous earth were used to obtain the samples. These wastes are usually dumped in landfills, but the current increase in restrictions on dumping and interest in improving the environment make our proposal for gaining value from these wastes a significant contribution. Laboratory tests show that the new aggregate has low bulk density and increased water absorption and porosity. The thermographic camera results provide evidence that new aggregates have significant insulating properties and are suitable for use on green roofs.

  10. The impact of green roof ageing on substrate characteristics and hydrological performance

    Science.gov (United States)

    De-Ville, Simon; Menon, Manoj; Jia, Xiaodong; Reed, George; Stovin, Virginia

    2017-04-01

    Green roofs contribute to stormwater management through the retention of rainfall and the detention of runoff. However, there is very limited knowledge concerning the evolution of green roof hydrological performance with system age. This study presents a non-invasive technique which allows for repeatable determination of key substrate characteristics over time, and evaluates the impact of observed substrate changes on hydrological performance. The physical properties of 12 green roof substrate cores have been evaluated using non-invasive X-ray microtomography (XMT) imaging. The cores comprised three replicates of two contrasting substrate types at two different ages: unused virgin samples; and 5-year-old samples from existing green roof test beds. Whilst significant structural differences (density, pore and particle sizes, tortuosity) between virgin and aged samples of a crushed brick substrate were observed, these differences did not significantly affect hydrological characteristics (maximum water holding capacity and saturated hydraulic conductivity). A contrasting substrate based upon a light expanded clay aggregate experienced increases in the number of fine particles and pores over time, which led to increases in maximum water holding capacity of 7%. In both substrates, the saturated hydraulic conductivity estimated from the XMT images was lower in aged compared with virgin samples. Comparisons between physically-derived and XMT-derived substrate hydrological properties showed that similar values and trends in the data were identified, confirming the suitability of the non-invasive XMT technique for monitoring changes in engineered substrates over time. The observed effects of ageing on hydrological performance were modelled as two distinct hydrological processes, retention and detention. Retention performance was determined via a moisture-flux model using physically-derived values of virgin and aged maximum water holding capacity. Increased water holding

  11. 坡屋顶的绿化技术%THE TECHNICAL MEASURES OF GREENING OF SLOPING ROOF

    Institute of Scientific and Technical Information of China (English)

    李海英; 杨洁

    2014-01-01

    The present study of roof greening is more concentrated in the flat roof , and less in the sloping roof .With respect to flat roof , loss of soil and water is the main problem of greening of sloping roofs .The paper studied anti-skid measures, irrigation and drainage system and combining with rainwater collection to popularize the design of greening of sloping roofs .%目前屋顶绿化的研究大多集中于平屋顶,而坡屋顶的较少;相对平屋顶,水土流失是坡屋顶绿化存在的主要问题。通过研究坡屋顶绿化的防滑措施、灌溉方式、蓄排水系统及结合雨水收集等关键技术来推广和普及坡屋顶绿化的设计。

  12. Structural changes of green roof growing substrate layer studied by X-ray CT

    Science.gov (United States)

    Jelinkova, Vladimira; Sacha, Jan; Dohnal, Michal; Snehota, Michal

    2017-04-01

    Increasing interest in green infrastructure linked with newly implemented legislation/rules/laws worldwide opens up research potential for field of soil hydrology. A better understanding of function of engineered soils involved in green infrastructure solutions such as green roofs or rain garden is needed. A soil layer is considered as a highly significant component of the aforesaid systems. In comparison with a natural soil, the engineered soil is assumed to be the more challenging case due to rapid structure changes early stages after its build-up. The green infrastructure efficiency depends on the physical and chemical properties of the soil, which are, in the case of engineered soils, a function of its initial composition and subsequent soil formation processes. The project presented in this paper is focused on fundamental processes in the relatively thick layer of engineered soil. The initial structure development, during which the pore geometry is altered by the growth of plant roots, water influx, solid particles translocation and other soil formation processes, is investigated with the help of noninvasive imaging technique  X-ray computed tomography. The soil development has been studied on undisturbed soil samples taken periodically from green roof test system during early stages of its life cycle. Two approaches and sample sizes were employed. In the first approach, undisturbed samples (volume of about 63 cm3) were taken each time from the test site and scanned by X-ray CT. In the second approach, samples (volume of about 630 cm3) were permanently installed at the test site and has been repeatedly removed to perform X-ray CT imaging. CT-derived macroporosity profiles reveal significant temporal changes of soil structure. Clogging of pores by fine particles and fissures development are two most significant changes that would affect the green roof system efficiency. This work has been supported by the Ministry of Education, Youth and Sports within

  13. Hyperspectral Monitoring of Green Roof Vegetation Health State in Sub-Mediterranean Climate: Preliminary Results.

    Science.gov (United States)

    Piro, Patrizia; Porti, Michele; Veltri, Simone; Lupo, Emanuela; Moroni, Monica

    2017-03-23

    In urban and industrial environments, the constant increase of impermeable surfaces has produced drastic changes in the natural hydrological cycle. Decreasing green areas not only produce negative effects from a hydrological-hydraulic perspective, but also from an energy point of view, modifying the urban microclimate and generating, as shown in the literature, heat islands in our cities. In this context, green infrastructures may represent an environmental compensation action that can be used to re-equilibrate the hydrological and energy balance and reduce the impact of pollutant load on receiving water bodies. To ensure that a green infrastructure will work properly, vegetated areas have to be continuously monitored to verify their health state. This paper presents a ground spectroscopy monitoring survey of a green roof installed at the University of Calabria fulfilled via the acquisition and analysis of hyperspectral data. This study is part of a larger research project financed by European Structural funds aimed at understanding the influence of green roofs on rainwater management and energy consumption for air conditioning in the Mediterranean area. Reflectance values were acquired with a field-portable spectroradiometer that operates in the range of wavelengths 350-2500 nm. The survey was carried out during the time period November 2014-June 2015 and data were acquired weekly. Climatic, thermo-physical, hydrological and hydraulic quantities were acquired as well and related to spectral data. Broadband and narrowband spectral indices, related to chlorophyll content and to chlorophyll-carotenoid ratio, were computed. The two narrowband indices NDVI705 and SIPI turned out to be the most representative indices to detect the plant health status.

  14. Temperature and snowfall trigger alpine vegetation green-up on the world's roof.

    Science.gov (United States)

    Chen, Xiaoqiu; An, Shuai; Inouye, David W; Schwartz, Mark D

    2015-10-01

    Rapid temperature increase and its impacts on alpine ecosystems in the Qinghai-Tibetan Plateau, the world's highest and largest plateau, are a matter of global concern. Satellite observations have revealed distinctly different trend changes and contradicting temperature responses of vegetation green-up dates, leading to broad debate about the Plateau's spring phenology and its climatic attribution. Large uncertainties in remote-sensing estimates of phenology significantly limit efforts to predict the impacts of climate change on vegetation growth and carbon balance in the Qinghai-Tibetan Plateau, which are further exacerbated by a lack of detailed ground observation calibration. Here, we revealed the spatiotemporal variations and climate drivers of ground-based herbaceous plant green-up dates using 72 green-up datasets for 22 herbaceous plant species at 23 phenological stations, and corresponding daily mean air temperature and daily precipitation data from 19 climate stations across eastern and southern parts of the Qinghai-Tibetan Plateau from 1981 to 2011. Results show that neither the continuously advancing trend from 1982 to 2011, nor a turning point in the mid to late 1990s as reported by remote-sensing studies can be verified by most of the green-up time series, and no robust evidence for a warmer winter-induced later green-up dates can be detected. Thus, chilling requirements may not be an important driver influencing green-up responses to spring warming. Moreover, temperature-only control of green-up dates appears mainly at stations with relatively scarce preseason snowfall and lower elevation, while coupled temperature and precipitation controls of green-up dates occur mostly at stations with relatively abundant preseason snowfall and higher elevation. The diversified interactions between snowfall and temperature during late winter to early spring likely determine the spatiotemporal variations of green-up dates. Therefore, prediction of vegetation growth

  15. The use of reactive material for limiting P-leaching from green roof substrate.

    Science.gov (United States)

    Bus, Agnieszka; Karczmarczyk, Agnieszka; Baryła, Anna

    2016-01-01

    The aim of the study is to assess the influence of drainage layer made of reactive material Polonite(®) on the water retention and P-PO(4) concentration in runoff. A column experiment was performed for extensive substrate underlined by 2 cm of Polonite(®) layer (SP) and the same substrate without supporting layer as a reference (S). The leakage phosphorus concentration ranged from 0.001 to 0.082 mg P-PO(4)·L(-1), with average value 0.025 P-PO(4)·L(-1) of S experiment and 0.000-0.004 P-PO(4)·L(-1) and 0.001 P-PO(4)·L(-1) of SP experiment, respectively. The 2 cm layer of Polonite(®) was efficient in reducing P outflow from green roof substrate by 96%. The average effluent volumes from S and SP experiments amounted 61.1 mL (5.8-543.3 mL) and 46.4 mL (3.3-473.3 mL) with the average irrigation rate of 175.5 mL (6.3-758.0 mL). The substrate retention ability of S and SP experiments was 65% and 74%, respectively. Provided with reactive materials, green roof layers implemented in urban areas for rain water retention and delaying runoff also work for protection of water quality.

  16. Discuss the Urban Green Roof Design%城市屋顶绿化设计探讨

    Institute of Scientific and Technical Information of China (English)

    张俐

    2014-01-01

    本文论述了屋顶绿化的特点及设计方式,通过推广屋顶绿化,可使生态景观建设从地面向空中拓展。既美化了人居环境,又节约了土地。%This article discusses the characteristics and design method of roof greening. Through the promotion of roof gree-ning, people can make the ecological landscape construction expand from the ground up to the sky, which not only beautify the environment, but also save the land.

  17. The hydrological performance of a green roof test bed under UK climatic conditions

    Science.gov (United States)

    Stovin, Virginia; Vesuviano, Gianni; Kasmin, Hartini

    2012-01-01

    SummaryThis paper presents new rainfall and runoff data from a UK green roof test bed which has been collected almost-continuously over a 29-month period from 01/01/2007 to 31/05/2009. Overall, the monitoring period was fairly typical of the location's long-term climatic averages, although the data set includes some extreme events in June 2007, which were associated with serious flooding locally. To focus on the system's performance under rainfall events likely to be of interest from an urban drainage/stormwater management perspective, return period analysis has been applied to identify those storm events with a rainfall depth in excess of 5 mm and a return period greater than one year. According to these criteria, 22 significant events have been identified, of which 21 have reliable runoff records. Overall the roof provided 50.2% cumulative annual rainfall retention, with a total volumetric retention equivalent to 30% during the significant events. The annual performance figures are towards the lower end of a range of international data, probably reflecting the fact that rainfall depths may be higher and evapotranspiration rates lower than in some more continental climatic settings. The roof's finite retention depth means that the maximum possible retention percentage declines as storm depth increases, and retention varied from between 0 and 20 mm, or 0% to 100%. Although some attenuation and delay of peak runoff is generally observed (mean peak flow reduction of 60% for the 21 significant events), the irregularity of natural rainfall patterns, combined with the variable influence of detention storage in specific events, makes the identification of peak-to-peak lag times difficult and arguably meaningless. Regression analyses have been undertaken to explore the potential to predict the roof's hydrological performance as a function of storm characteristics. However, these are shown to have poor predictive capability, even for the system from which they were derived

  18. 屋顶绿化节能效益研究%Benefit of Energy Efficiency of Green Roofs

    Institute of Scientific and Technical Information of China (English)

    王丹; 管乃彦

    2015-01-01

    屋顶绿化是在改善城市区域的生态环境,美化城市景观,并且在有限的城市空间提高绿地率最有效的方式。屋顶绿化不但可以缓解城市热岛效应,还可以在节能和城市绿化方面发挥很好的作用。借助天津地区多层建筑的顶层房间为研究对象,综述多种不同的屋顶绿化构造及施工方式。通过 DesignBuilder 软件对非绿化与绿化屋顶房间在能耗方面进行分析模拟,采用碳税率法对屋顶绿地的固碳经济价值进行评估,将各项生态效益的经济价值进行计算,屋顶绿化对节能十分有效。%Roof greening is the most efficient way to improve the greening rate in limited urban space. It can not only alleviate the urban heat island effect, but also play a good role in energy conservation and urban greening. As the research object, the top floor of multi-story buildings in Tianjin combines with various structures of roof greening and ways of construction. The paper is to analyze and simulate differences of energy consumption between non-greening roof and greening roof by DesignBuilder software, and finally gets a conclusion that greening roof is available in energy efficiency.

  19. Green roof seasonal variation: comparison of the hydrologic behavior of a thick and a thin extensive system in New York City

    Science.gov (United States)

    Elliott, R. M.; Gibson, R. A.; Carson, T. B.; Marasco, D. E.; Culligan, P. J.; McGillis, W. R.

    2016-07-01

    Green roofs have been utilized for urban stormwater management due to their ability to capture rainwater locally. Studies of the most common type, extensive green roofs, have demonstrated that green roofs can retain significant amounts of stormwater, but have also shown variation in seasonal performance. The purpose of this study is to determine how time of year impacts the hydrologic performance of extensive green roofs considering the covariates of antecedent dry weather period (ADWP), potential evapotranspiration (ET0) and storm event size. To do this, nearly four years of monitoring data from two full-scale extensive green roofs (with differing substrate depths of 100 mm and 31 mm) are analyzed. The annual performance is then modeled using a common empirical relationship between rainfall and green roof runoff, with the addition of Julian day in one approach, ET0 in another, and both ADWP and ET0 in a third approach. Together the monitoring and modeling results confirm that stormwater retention is highest in warmer months, the green roofs retain more rainfall with longer ADWPs, and the seasonal variations in behavior are more pronounced for the roof with the thinner media than the roof with the deeper media. Overall, the ability of seasonal accounting to improve stormwater retention modeling is demonstrated; modification of the empirical model to include ADWP, and ET0 improves the model R 2 from 0.944 to 0.975 for the thinner roof, and from 0.866 to 0.870 for the deeper roof. Furthermore, estimating the runoff with the empirical approach was shown to be more accurate then using a water balance model, with model R 2 of 0.944 and 0.866 compared to 0.975 and 0.866 for the thinner and deeper roof, respectively. This finding is attributed to the difficulty of accurately parameterizing the water balance model.

  20. Thermally insulating green roof with model function. Roof gardens gain acceptance; Waermedaemmendes Gruendach mit Vorbildfunktion. Dachbegruenung macht Schule

    Energy Technology Data Exchange (ETDEWEB)

    Appl, Roland [ZinCo GmbH, Unterensingen (Germany)

    2010-07-01

    The new built consolidated school for physically disabled and speech handicapped persons in the Swabian Dettingen/Teck (Federal Republic of Germany) has a model function in every sense. This school provides a space for the promotion and personal development for more than 120 pupils from the region around Kirchheim (Federal Republic of Germany). In addition, a kindergarten for speech handicapped infants is integrated. The school is future-oriented and exemplary not only in its function, but also in its outside form. Wood as a naturally grown building material covers the fronts, and plants decorate the roofs. The heat insulating roof planting makes a substantial contribution to the structural thermal protection.

  1. Advantages of a Vertical High-Resolution Distributed-Temperature-Sensing System Used to Evaluate the Thermal Behavior of Green Roofs

    Science.gov (United States)

    Hausner, M. B.; Suarez, F. I.; Cousiño, J. A.; Victorero, F.; Bonilla, C. A.; Gironas, J. A.; Vera, S.; Bustamante, W.; Rojas, V.; Leiva, E.; Pasten, P.

    2015-12-01

    Technological innovations used for sustainable urban development, green roofs offer a range of benefits, including reduced heat island effect, rooftop runoff, roof surface temperatures, energy consumption, and noise levels inside buildings, as well as increased urban biodiversity. Green roofs feature layered construction, with the most important layers being the vegetation and the substrate layers located above the traditional roof. These layers provide both insulation and warm season cooling by latent heat flux, reducing the thermal load to the building. To understand and improve the processes driving this thermal energy reduction, it is important to observe the thermal dynamics of a green roof at the appropriate spatial and temporal scales. Traditionally, to observe the thermal behavior of green roofs, a series of thermocouples have been installed at discrete depths within the layers of the roof. Here, we present a vertical high-resolution distributed-temperature-sensing (DTS) system installed in different green roof modules of the Laboratory of Vegetated Infrastructure for Buildings (LIVE -its acronym in Spanish) of the Pontifical Catholic University of Chile. This DTS system allows near-continuous measurement of the thermal profile at spatial and temporal resolutions of approximately 1 cm and 30 s, respectively. In this investigation, the temperature observations from the DTS system are compared with the measurements of a series of thermocouples installed in the green roofs. This comparison makes it possible to assess the value of thermal observations at better spatial and temporal resolutions. We show that the errors associated with lower resolution observations (i.e., from the thermocouples) are propagated in the calculations of the heat fluxes through the different layers of the green roof. Our results highlight the value of having a vertical high-resolution DTS system to observe the thermal dynamics in green roofs.

  2. Capacity of Green Roof on CO2 Absorption%屋顶绿化二氧化碳减排效益的研究

    Institute of Scientific and Technical Information of China (English)

    徐鹏; 邓超; 林钊; 张超; 方元; 吴灵玲; 胡辉

    2012-01-01

    屋顶绿化不仅能够美化城市环境,而且对城市二氧化碳减排具有一定作用.文章利用自行设计的熏气装置对几种常见屋顶绿化植物进行CO2熏气实验,测定其对CO2的吸收速率和影响因素;实验结果表明,红叶石楠、红继木和石榴等绿化植物对CO2具有显著的吸收能力,其中红叶石楠的吸收速率最高,达7.058 L/(m2·d),绿化植物对CO2的吸收速率受屋面温度影响较大,温度超过34℃时吸收速率快速减小;在实验观测基础上,结合武汉城市区域气候特征、建筑物荷载能力、屋顶绿化可用面积等信息,分析得到武汉市进行规模化屋顶绿化之后,每年可吸收转化CO2 1.696×106t,相当于一个194 MW火力发电厂一年的CO2排放量,屋顶绿化的发展前景较可观.%Green roof not only can beautify the environment, but also has a certain effect on reduction of carbon dioxide emission in urban. CO2 absorption rate of some common green roof plants and its influencing factors were studied by self-designed fumigation experimental device. Results showed that Photinia fraseri, red after-wood and pomegranate have a good ability to absorb CO2, among which Photinia fraseri has the best CO2 absorption ability about 7.058 L/(m2·d). CO2 absorption rate of green plants has more relationship with roof temperature, and the absorption rates decrease rapidly when temperature exceeds 34 ℃. Based on the experiment results, together with regional climate characteristics of Wuhan, load bearing capacity of the building and usable area for green roof, the capacity of green roof on CO2 emission reduction was 1.696X106 t/a, which was equal to CO2 emission from a thermal power plant with 194 MW in 1 year. Development prospects of capacity of green roof on CO2 absorption were investigated as well.

  3. Moisture content behaviour in extensive green roofs during dry periods: The influence of vegetation and substrate characteristics

    Science.gov (United States)

    Berretta, Christian; Poë, Simon; Stovin, Virginia

    2014-04-01

    Evapotranspiration (ET) is a key parameter that influences the stormwater retention capacity, and thus the hydrological performance, of green roofs. This paper investigates how the moisture content in extensive green roofs varies during dry periods due to evapotranspiration. The study is supported by 29 months continuous field monitoring of the moisture content within four green roof test beds. The beds incorporated three different substrates, with three being vegetated with sedum and one left unvegetated. Water content reflectometers were located at three different soil depths to measure the soil moisture profile and to record temporal changes in moisture content at a five-minute resolution. The moisture content vertical profiles varied consistently, with slightly elevated moisture content levels being recorded at the deepest substrate layer in the vegetated systems. Daily moisture loss rates were influenced by both temperature and moisture content, with reduced moisture loss/evapotranspiration when the soil moisture was restricted. The presence of vegetation resulted in higher daily moisture loss. Finally, it is demonstrated that the observed moisture content data can be accurately simulated using a hydrologic model based on water balance and two conventional Potential ET models (Hargreaves and FAO56 Penman-Monteith) combined with a soil moisture extraction function. Configuration-specific correction factors have been proposed to account for differences between green roof systems and standard reference crops.

  4. Research on the Cooling Effect of Green Roof%屋顶绿化降温效果研究

    Institute of Scientific and Technical Information of China (English)

    肖拓; 曹佩琴; 魏甲斌; 甘德欣

    2014-01-01

    随着屋顶绿化的发展,研究屋顶绿化作为改善城市生态环境的策略之一越来越受到人们的重视。为了研究屋顶绿化对建筑内、外表面的降温效果,选取屋顶绿化实地测量,通过对测量数据的量化分析,结合国内外相关的研究方法和长沙市独特的气候背景,论证屋顶绿化后建筑温度的变化及对于城市热环境的改善。%As the development of green roof, it is more and more concerned of the research about green roof which was applied in the ecological improvement of cities environment. The paper was concentrated on the cooling effect in buildings interior and outdoor of green roof. Through field measurement and the quantitative analysis of metric data, combined with the research method abroad and at home and the unique climate of Changsha, the essay demonstrated the temperature decrease and the improvement of urban thermal environment after the green roof was carried out.

  5. A Study on the Impact of Vegetation and Green Roof on Increasing the Wind Speed and Pollutants Dispersion in the Urban Canyons Based on Computational Fluid Dynamics Model

    Directory of Open Access Journals (Sweden)

    SH Hosseini

    2016-12-01

    Full Text Available Background and Objective: Increasing population growth and construction of high-rise buildings have doubled the amount of environmental pollution in the cities. Moreover, people use the open urban spaces more than before in order to meet their ecological needs. Accordingly, some parameters such as various vegetation and continuous winds streams can be considerably influential in transmittance of the particle pollution.  Therefore, the aim of this research was to study the impacts of different green roofs on the dispersion of pollutants in the standpoint of height and density for urban airflow condition of Shiraz City, Iran. Materials and Methods: In this study, a literature review in the field computer simulation with the help of computational fluid dynamics (CFD model in Envi-met software environment was used. Results: Regarding the importance of using vegetation in the urban spaces, vertical dispersion of the particles in presence of vegetation was explored. By comparing the basic model (without vegetation results with models including vegetation with short, medium and high crowns, it was revealed that vegetation with medium crowns is the closest model to the basic model with a difference of 7.65 m2/s in terms of vertical dispersion of particles; in fact, it was the most optimized condition for maximizing the dispersion of environmental pollutants. Conclusion: The results showed that the green roofs in the buildings increase the horizontal dispersion of the particulate pollution and decrease this term in the vertical dispersion. Finally, by an expansion of green roof usage in the buildings the sustainability in architecture and urbanism can be achieved.

  6. Parameters influencing the regeneration of a green roof's retention capacity via evapotranspiration

    Science.gov (United States)

    Poë, Simon; Stovin, Virginia; Berretta, Christian

    2015-04-01

    The extent to which the finite hydrological capacity of a green roof is available for retention of a storm event largely determines the scale of its contribution as a Sustainable Drainage System (SuDS). Evapotranspiration (ET) regenerates the retention capacity at a rate that is variably influenced by climate, vegetation treatment, soil and residual moisture content. Experimental studies have been undertaken to monitor the drying cycle behaviour of 9 different extensive green roof configurations with 80 mm substrate depth. A climate-controlled chamber at the University of Sheffield replicated typical UK spring and summer diurnal cycles. The mass of each microcosm, initially at field capacity, was continuously recorded, with changes inferred to be moisture loss/gain (or ET/dew). The ranges of cumulative ET following a 28 day dry weather period (ADWP) were 0.6-1.0 mm/day in spring and 0.7-1.25 mm/day in summer. These ranges reflect the influence of configuration on ET. Cumulative ET was highest from substrates with the greatest storage capacity. Significant differences in ET existed between vegetated and non-vegetated configurations. Initially, seasonal mean ET was affected by climate. Losses were 2.0 mm/day in spring and 3.4 mm/day in summer. However, moisture availability constrained ET, which fell to 1.4 mm/day then 1.0 mm/day (with an ADWP of 7 and 14 days) in spring; compared to 1.0 mm/day and 0.5 mm/day in summer. A modelling approach, which factors Potential Evapotranspiration (PET) according to stored moisture content, predicts daily ET with very good accuracy (PBIAS = 2.0% [spring]; -0.8% [summer]).

  7. The Influence of Hydrologic Parameters on the Hydraulic Efficiency of an Extensive Green Roof in Mediterranean Area

    Directory of Open Access Journals (Sweden)

    Giuseppina Garofalo

    2016-01-01

    Full Text Available In an urban environment, green roofs represent a sustainable solution for mitigating stormwater volumes and hydrograph peaks. So far, many literature studies have investigated the hydraulic efficiency and the subsurface runoff coefficient of green roofs, showing their strong variability according to several factors, including the characteristics of storm events. Furthermore, only few studies have focused on the hydraulic efficiency of green roofs under Mediterranean climate conditions and defined the influencing hydrological parameters on the subsurface runoff coefficient. Nevertheless, for designing purposes, it is crucial to properly assess the subsurface runoff coefficient of a given green roof under specific climate conditions and its influencing factors. This study intends to, firstly, evaluate the subsurface runoff coefficient at daily and event-time scales for a given green roof, through a conceptual model implemented in SWMM. The model was loaded with both daily and 1-min rainfall data from two Mediterranean climate sites, one in Thessaloniki, Greece and one in Cosenza, Italy, respectively. Then, the most influencing hydrological parameters were examined through a statistical regression analysis. The findings show that the daily subsurface runoff coefficient is 0.70 for both sites, while the event-based one is 0.79 with a standard deviation of 0.23 for the site in Cosenza, Italy. The multiple linear regression analysis revealed that the influencing parameters are the rainfall intensity and antecedent dry weather period with a confidence level of 95%. This study demonstrated that, due to the high variability of the subsurface runoff coefficient, the use of a unique value for design purposes is inappropriate and that a preliminary estimation could be obtained as a function of the total rainfall depth and the antecedent dry weather period by using the validated multi-regression relationship which is site specific.

  8. Green and cool roofs to mitigate urban heat island effects in the Chicago metropolitan area: evaluation with a regional climate model

    Science.gov (United States)

    Sharma, A.; Conry, P.; Fernando, H. J. S.; Hamlet, Alan F.; Hellmann, J. J.; Chen, F.

    2016-06-01

    The effects of urban heat islands (UHIs) have a substantial bearing on the sustainability of cities and environs. This paper examines the efficacy of green and cool roofs as potential UHI mitigation strategies to make cities more resilient against UHI. We have employed the urbanized version of the Weather Research and Forecasting (uWRF) model at high (1 km) resolution with physically-based rooftop parameterization schemes (conventional, green and cool), a first-time application to the Chicago metropolitan area. We simulated a hot summer period (16-18 August 2013) and assessed (i) UHI reductions for different urban landuse with green/cool roofs, (ii) the interaction of lake breeze and UHI, and (iii) diurnal boundary layer dynamics. The performance of uWRF was evaluated using sensible heat flux and air temperature measurements from an urban mini-field campaign. The simulated roof surface energy balance captured the energy distribution with respective rooftop algorithms. Results showed that daytime roof temperature reduced and varied linearly with increasing green roof fractions, from less than 1 °C for the case of 25% green roof to ˜3 °C during peak daytime for 100% green roof. Diurnal transitions from land to lake breeze and vice versa had a substantial impact on the daytime cycle of roof surface UHI, which had a 3-4 hour lag in comparison to 2 m UHI. Green and cool roofs reduced horizontal and vertical wind speeds and affected lower atmosphere dynamics, including reduced vertical mixing, lower boundary layer depth, and weaker convective rolls. The lowered wind speeds and vertical mixing during daytime led to stagnation of air near the surface, potentially causing air quality issues. The selection of green and cool roofs for UHI mitigation should therefore carefully consider the competing feedbacks. The new results for regional land-lake circulations and boundary layer dynamics from this study may be extended to other urbanized areas, particularly to coastal

  9. On the Green Roof Development in Wuhan%浅谈屋顶绿化在武汉的发展

    Institute of Scientific and Technical Information of China (English)

    李岚

    2012-01-01

    Expansion of urban green space, and try to develop and expand the city total plant biotcchnology is the funda- mental way to improve the city's ecological environment. Practice has proved that the planning and design of urban greening at home and abroad, the green roof is conservation land, an effective way to develop urban green space. As early as in the 1980s, Wuhan have "green roof." However, so far, Wuhan green roof also failed to form climate. Statistics, Wuhan green roof Status is the city's only 89, a total of approximately 82,000 square meters. This is compared to idle up to hundreds of millions of square meters of roof area, the gap is too great. Green roofs should be widely combined with the demand for energy-saving building standards and urban ecological environment construction and development direction, more perfect, more systematic and deeper pursued.%扩展城市绿化空间,尽量地发展和扩大城市植物生物总量,是改善城市生态环境的根本出路。国内外城市绿化规划设计的实践证明,屋顶绿化是节约土地、开拓城市绿化空间的有效办法。早在上世纪80年代,武汉市就有"屋顶绿化"。但是,到目前为止,武汉的屋顶绿化也未能形成气候。据统计,武汉屋顶绿化现状是,全市仅89处,共约8.2万平米。这与高迭数亿平米的闲置屋顶面积相比,差距实在太大。因此,屋顶绿化应广泛结合节能建筑标准需求及城市生态环境建设发展方向,更完善、更系统、更深层次地开展下去。

  10. Optimal location selection for the installation of urban green roofs considering honeybee habitats along with socio-economic and environmental effects.

    Science.gov (United States)

    Gwak, Jae Ha; Lee, Bo Kyeong; Lee, Won Kyung; Sohn, So Young

    2017-03-15

    This study proposes a new framework for the selection of optimal locations for green roofs to achieve a sustainable urban ecosystem. The proposed framework selects building sites that can maximize the benefits of green roofs, based not only on the socio-economic and environmental benefits to urban residents, but also on the provision of urban foraging sites for honeybees. The framework comprises three steps. First, building candidates for green roofs are selected considering the building type. Second, the selected building candidates are ranked in terms of their expected socio-economic and environmental effects. The benefits of green roofs are improved energy efficiency and air quality, reduction of urban flood risk and infrastructure improvement costs, reuse of storm water, and creation of space for education and leisure. Furthermore, the estimated cost of installing green roofs is also considered. We employ spatial data to determine the expected effects of green roofs on each building unit, because the benefits and costs may vary depending on the location of the building. This is due to the heterogeneous spatial conditions. In the third step, the final building sites are proposed by solving the maximal covering location problem (MCLP) to determine the optimal locations for green roofs as urban honeybee foraging sites. As an illustrative example, we apply the proposed framework in Seoul, Korea. This new framework is expected to contribute to sustainable urban ecosystems.

  11. 郑州市屋顶绿化现状及分析%The Roof Greening Situation and Analysis of Zhengzhou

    Institute of Scientific and Technical Information of China (English)

    张秋红

    2014-01-01

    屋顶绿化在城市绿化美化中占有重要作用,拥有巨大的市场潜力。通过对郑州市现有及施工中屋顶花园的调查勘测,从屋顶绿化的设计和工程两大部分进行研究分析,并对比两种屋顶绿化的建造形式(简单式屋顶绿化和花园式屋顶绿化)。总结郑州市屋顶绿化规划中存在的问题与不足,并针对这些问题和不足提出改进措施和规划意见。%Roof greening plays an important role in urban greening landscaping, and has huge market potential. Based on the investigation of roof garden existing and under construction in Zhengzhou, two parts that contained the design and engineering of roof greening were analyzed. And the two roof greening construction forms (simple roof greening and garden green roof) were compared. This paper summarized the existing problems about roof greening planning of Zhengzhou, and put forward some superficial improvement measures and planning ideas to solve these problems and deficiencies.

  12. 三明市屋顶绿化植物选择初探%Study on selection of roof greening plants in Sanming

    Institute of Scientific and Technical Information of China (English)

    吴春敏

    2014-01-01

    In light of present situation and the existing problems of greening in Sanming, the requirements of selecting roof greening plants are analyzed in this paper. Combined with the successful case of roof greening in Fuzhou, some plants are selected as alternative roof greening plants for the reference of roof greening in Sanming.%﹕该文针对三明市绿化现状及存在的问题,分析屋顶绿化植物选择要求,结合福州市屋顶绿化的成功实例,筛选出可用于三明市屋顶绿化的植物,以供三明市屋顶绿化参考。

  13. Suggestions of promoting Jinan city roof greening construction%济南市推行屋顶绿化建设的建议

    Institute of Scientific and Technical Information of China (English)

    李艳伟

    2016-01-01

    With an discussion of the meaning of promoting roof greening,combining with internal and external roof greening construction status, the paper analyzes problems existing in Jinan roof greening construction,and puts forward roof greening construction countermeasures from aspects of broadcasting strength,formulating perfect norms and cultivating plants planting and so on,so as to improve city greening coverage rate.%论述了推广屋顶绿化建设的意义,结合国内外屋顶绿化建设的现状,分析了济南市屋顶绿化建设中存在的问题,从加大宣传力度、制定完善规范、培养绿植种类等方面,提出了屋顶绿化建设的对策,从而大幅度地提高城市绿化覆盖率.

  14. Toward an operational tool to simulate green roof hydrological impact at the basin scale: a new version of the distributed rainfall-runoff model Multi-Hydro.

    Science.gov (United States)

    Versini, Pierre-Antoine; Gires, Auguste; Tchinguirinskaia, Ioulia; Schertzer, Daniel

    2016-10-01

    Currently widespread in new urban projects, green roofs have shown a positive impact on urban runoff at the building scale: decrease and slow-down of the peak discharge, and decrease of runoff volume. The present work aims to study their possible impact at the catchment scale, more compatible with stormwater management issues. For this purpose, a specific module dedicated to simulating the hydrological behaviour of a green roof has been developed in the distributed rainfall-runoff model (Multi-Hydro). It has been applied on a French urban catchment where most of the building roofs are flat and assumed to accept the implementation of a green roof. Catchment responses to several rainfall events covering a wide range of meteorological situations have been simulated. The simulation results show green roofs can significantly reduce runoff volume and the magnitude of peak discharge (up to 80%) depending on the rainfall event and initial saturation of the substrate. Additional tests have been made to assess the susceptibility of this response regarding both spatial distributions of green roofs and precipitation. It appears that the total area of greened roofs is more important than their locations. On the other hand, peak discharge reduction seems to be clearly dependent on spatial distribution of precipitation.

  15. Roof greening construction development in the future-On the development of building roof greening in Jiaxing suggestions%建筑屋顶绿化发展的未来--关于嘉兴市发展建筑屋顶绿化的建议

    Institute of Scientific and Technical Information of China (English)

    沈栋栋; 阮雪琴; 叶苏淼; 吴翌丹; 周宏杰

    2015-01-01

    The vigorous development of roof greening in Jiaxing wil give Jiaxing wil bring a new ecological city appearance. Describes the origin of roof greening, il ustrates the function of roof greening, roof greening were investigated and fine grass seed, the defects of the roof greening in Jia xing are studied, and some suggestions were put forward.%嘉兴屋顶绿化的蓬勃发展必定给嘉兴将带来一个全新的生态城市面貌。概括了屋顶绿化的起源,阐述了屋顶绿化的功能,进行了优良屋顶绿化草种的调查,对当前嘉兴屋顶绿化存在的不足进行了研究,并提出了建议。

  16. 基于屋顶绿化的构造层次研究%Study on Building Roof Greening Structure

    Institute of Scientific and Technical Information of China (English)

    李恒威

    2012-01-01

    通过对常见平屋顶绿化构造层次进行分析研究.将过滤层、蓄排水层、阻根穿刺防水层采用集成式的方法综合为复合蓄排水毡层,起到维修容易、减少屋顶荷载等作用.并对坡屋顶绿化种植土滑移现象进行处理,提出坡屋面培植土网格固定的方法.实际工程证明方法合理,效果明显,便于大范围的推广.%Through to the common flat roof structure of roof greening level research, the filter layer, drainage layer, root resistance waterproof layer are used puncture integrated method for composite drainage mat layer, to reduce the roof load, improve the level of repair because of the defects of difficult. The slope of the roof greening planting soil slip phenomenon, the methods for solving the mesh fixation is put forward. Practical engineering method is reasonable, obvious effect, convenient popularization in large scope.

  17. 浅谈建筑构建中屋顶绿化的思路%The Thought of Construction of Roof Greening

    Institute of Scientific and Technical Information of China (English)

    洪澜

    2014-01-01

    By analyzing the current situation in the construction of green roofs constructed, indicating the importance of the green roof, combined with the lack of green roofs of buildings in the development of this project, pointed out the direction and path of development applied after green roof.%通过对建筑构建中屋顶绿化现状的分析,说明了屋顶绿化的重要性,并结合我国建筑中屋顶绿化这一工程发展的不足,指出屋顶绿化以后的应用方向和发展道路。

  18. Research on Remote Sensing Application in the Investigation of Green Roof%遥感在屋顶绿化调查中的应用研究

    Institute of Scientific and Technical Information of China (English)

    李沛鸿; 张晓玉

    2011-01-01

    Urban roof garden is an important part of the City Green. The traditional measuring methods are unable to meet the investigation needs. Taking remote sensing technique to investigate the urban roof green is an effective method. This paper mainly discusses the method and procedure of extracting roof green area from the RS image, and the application prospect of RS in the Roof Green.%城市屋顶花园是城市绿化的重要组成部分,传统的测量方法无法满足现实需要.利用遥感技术进行城市屋顶花园调查是有效的方法,论文主要探讨了从遥感影像中提取屋顶绿化面积的方法和步骤,以及遥感在屋顶绿地方面的应用前景.

  19. Assessing chilling and drought tolerance of different plant genera on extensive green roofs in an arid climate region in Iran.

    Science.gov (United States)

    Vahdati, Navid; Tehranifar, Ali; Kazemi, Fatemeh

    2017-05-01

    The harsh and stressful growing environment of extensive green roofs especially in arid environments allows a limited range of plant species to survive. Therefore, achieving plantings to survive in such conditions is a significant challenge. This paper describes an experiment investigating plant selections for extensive green roofs based on chilling (cold season) and drought (warm season) conditions of Iran. Nine species were selected from the three major taxonomic and functional plant groups that are commonly used on extensive green roofs including grasses, groundcovers and sedums. The species namely Agropyron cristatum, Festuca aurundinacea, Festuca ovina, Potentila sp., Frankinia thymifolia, Vinca minor, Sedum acre, Sedum spurinum, Carpobrotus edulis were imposed to natural chilling in autumn and winter using a randomized complete block design. For spring and summer, irrigation regimes at levels (48, 72 and 96 h intervals) in a factorial experiment based on a randomized complete block design with four replications were applied. The results showed that Agropyron cristatum, Frankinia thymifolia and Carpobrotus edulis were the best plants from each class. Carpobrotus edulis was the best choice for cold and warm seasons and this was followed by Frankinia thymifolia and Potentila sp. Vinca minor performed well in the cold seasons and Sedum spurinum appeared to be excellent in the warm seasons. The plants of the experiment showed significantly different appearances in different watering regimes. Little differences in drought tolerances were observed among the forbs and grasses, which must be watered during warm seasons. However, the succulents responded very well to the drought and low watering regimes. Overall, succulents and groundcovers were considered more appropriate for application in warm and cold seasons, respectively. According to the findings, drought and cold weather conditions cannot be a major obstacle for developing extensive green roofs in Iran if

  20. DEVELOPMENT OF DESIGNING AND APPLICATION OF GREEN ROOFS%国内外屋顶的绿化设计

    Institute of Scientific and Technical Information of China (English)

    肖敏; 张国强

    2015-01-01

    屋顶绿化是建筑节能的一种有效措施,具有显著的生态效益和景观价值,已越来越多地引起了建筑领域及相关人员的广泛关注。通过系统分析屋顶绿化在促进建筑节能、改善环境和蓄积雨水等方面的作用和效果,研究总结了国内外屋顶绿化设计的方法及其主要影响因素,包括配置模式、植被材料和栽培基质等方面的研究成果,对国内外屋顶绿化政策和实践的发展进行了回顾和比较。%As an effective measure for improvement of building energy efficiency , green roof has obvious biobenefit and landscape value , which is attracting more and more attention both in China and internationally .Through a systematic research on the effects of green roof in improving building energy saving , environment and rain accumulation , it was studied the design methods of green roof and its major influencing factors , including vegetation materials, allocation modes and cultivation substratum; and it was also reviews the progress of governmental policy and practice of green roofs in China and other countries .

  1. Investigation of a novel multifunctional roof panel for hybrid photovoltaic/thermal/daylight application in atrium and large green house

    OpenAIRE

    Yu, Xu

    2015-01-01

    Daylight is an energy efficient solution for illumination and visual comfort in buildings. However, successful daylight design requires effective daylight control technology to eliminate the negative impact such as overheating, unbalanced indoor daylight distribution and glare. With this mind, the current thesis presents a novel multifunctional roof panel which might be applied in atrium and large green house. The working principle of the panel is based on the non-imaging low-concentration so...

  2. 韩国屋顶绿化的激励制度和技术%Incentive System and Technology of Roof Greening in South Korea

    Institute of Scientific and Technical Information of China (English)

    赵红露; 姜太昊

    2013-01-01

    In the city the shortage of using land and the rapid increase of population bring many negative effects, while the rise of roof greening provides a new green compensation method. The roof greening is a green corridor to connect to the city, and it has an extremely important role in the theme of the low carbon green growth. The relevant laws and regulations, incentive system, roof greening technology, and the level of South Korea roof greening development are introduced. On the basis of foreign modern experience, it can combine the fact of China and provide a reference for the formulation of roof greening policies, roof greening technology, to accelerate the development of urban roof greening cause.%城市用地紧张,人口剧增,带来众多的负面影响.屋顶绿化是城市绿化用地在极端紧缺的条件下出现的新的绿化补偿手段.是连接城市的绿色廊道,在低碳绿色生长的主题下有着极其重要的作用.介绍了韩国屋顶绿化相关的法规、激励制度、绿化技术,说明了韩国屋顶绿化的发展水平.在借鉴国外先进经验的基础上,结合我国的实际情况,旨在为我国屋顶绿化政策的制定,绿化技术的研究提供参考,促进我国城市屋顶绿化事业的发展.

  3. Green-roof as a solution to solve stormwater management issues? Assessment on a long time period at the parcel scale

    Science.gov (United States)

    Versini, P.-A.; Petrucci, G.; de Gouvello, B.

    2014-09-01

    Experimental green-roof rainfall-runoff observations have shown a positive impact on stormwater management at the building scale; with a decrease in the peak discharge and a decrease in runoff volume. This efficiency of green-roofs varies from one rainfall event to another depending on precipitation characteristics and substrate antecedent conditions. Due to this variability, currently, green-roofs are rarely officially used as a regulation tool to manage stormwater. Indeed, regulation rules governing the connection to the stormwater network are usually based on absolute threshold values that always have to be respected: maximum areal flow-rate or minimum retention volume for example. In this context, the aim of this study is to illustrate how a green-roof could represent an alternative to solve stormwater management issues, if the regulation rules were further based on statistics. For this purpose, a modelling scheme has been established at the parcel scale to simulate the hydrological response of several roof configurations: impervious, strictly regulated (in terms of areal flow-rate or retention volume), and covered by different types of green-roof matter. Simulations were carried out on a long precipitation time period (23 years) that included a large and heterogeneous set of hydrometeorological conditions. Results obtained for the different roof configurations were compared. Based on the return period of the rainfall event, the probability to respect some regulation rules (defined from real situations) was assessed. They illustrate that green-roofs reduce stormwater runoff compared to an impervious roof surface and can guarantee the respect of the regulation rules in most of the cases. Moreover, their implementation can appear more realistic than that of other infrastructures strictly complying with regulations and demanding significant storage capacity.

  4. Physico-technical measurement of green roof in climate chamber module

    Directory of Open Access Journals (Sweden)

    Baláž Richard

    2015-06-01

    Full Text Available Not for nothing it is said that "a good roof is priceless." Although it may lead to discussions, which roof is good, because there are a lot of requirements and criteria for the functional characterization. It must be understood that the roof structure defines the durability of the building as a unit, therefore it defines lifetime of other parts of the building and also the function of space that is covered by the roof. Therefore it is very important to pay particular attention to the design, as well as the realization of the roof structure. The aim of this publication is to judge the physical and technical parameters in the design of the roof coating module in a climatic chamber.

  5. INFLUENCE OF CYCLIC FREEZING AND THAWING ON THE HYDRAULIC CONDUCTIVITY OF SELECTED AGGREGATES USED IN THE CONSTRUCTION OF GREEN ROOFS

    Directory of Open Access Journals (Sweden)

    Karolina Gwóżdź

    2016-09-01

    Full Text Available The construction of a green roof requires drainage which ought to be characterized by adequate hydraulic conductivity and be resistant to changing meteorological conditions during the winter period. A properly functioning drainage system guarantees the reliability of the entire green roof system. The article presents studies on the freeze-thaw durability and hydraulic conductivity of selected aggregates applied for constructing green roof drainage systems. The aggregates were subjected to a cyclic freezing and thawing process in 30 and 70 cycles. The obtained results indicate that the conductivity of aggregates studied using the constant head method decreases along with an increase in the number of freeze-thaw cycles they were subjected to. This means that the indicator of freeze-thaw durability can have an indicative nature in the assessment of the usefulness of selected aggregates for constructing drainage layers. The conducted studies indicate that the deciding parameter when selecting an aggregate ought to be its hydraulic conductivity, determined accounting for the changes taking place in the freeze-thaw cycles. The equations of changes in the conductivity of aggregates indicated by the authors make it possible to assess them for practical purposes.

  6. Growing substrates for aromatic plant species in green roofs and water runoff quality: pilot experiments in a Mediterranean climate.

    Science.gov (United States)

    Monteiro, Cristina M; Calheiros, Cristina S C; Palha, Paulo; Castro, Paula M L

    2017-09-01

    Green roof technology has evolved in recent years as a potential solution to promote vegetation in urban areas. Green roof studies for Mediterranean climates, where extended drought periods in summer contrast with cold and rainy periods in winter, are still scarce. The present research study assesses the use of substrates with different compositions for the growth of six aromatic plant species - Lavandula dentata, Pelargonium odoratissimum, Helichrysum italicum, Satureja montana, Thymus caespititius and T. pseudolanuginosus, during a 2-year period, and the monitoring of water runoff quality. Growing substrates encompassed expanded clay and granulated cork, in combination with organic matter and crushed eggshell. These combinations were adequate for the establishment of all aromatic plants, allowing their propagation in the extensive system located on the 5th storey. The substrate composed of 70% expanded clay and 30% organic matter was the most suitable, and crushed eggshell incorporation improved the initial plant establishment. Water runoff quality parameters - turbidity, pH, conductivity, NH4(+), NO3(-), PO4(3-) and chemical oxygen demand - showed that it could be reused for non-potable uses in buildings. The present study shows that selected aromatic plant species could be successfully used in green roofs in a Mediterranean climate.

  7. Cladonia lichens on extensive green roofs: evapotranspiration, substrate temperature, and albedo [v1; ref status: indexed, http://f1000r.es/2ha

    Directory of Open Access Journals (Sweden)

    Amy Heim

    2013-12-01

    Full Text Available Green roofs are constructed ecosystems that provide ecosystem services in urban environments. Shallow substrate green roofs subject the vegetation layer to desiccation and other environmental extremes, so researchers have evaluated a variety of stress-tolerant vegetation types for green roof applications. Lichens can be found in most terrestrial habitats.  They are able to survive extremely harsh conditions, including frequent cycles of desiccation and rehydration, nutrient-poor soil, fluctuating temperatures, and high UV intensities. Extensive green roofs (substrate depth <20cm exhibit these harsh conditions, making lichens possible candidates for incorporation into the vegetation layer on extensive green roofs.  In a modular green roof system, we tested the effect of Cladonia lichens on substrate temperature, water loss, and albedo compared to a substrate-only control. Overall, the Cladonia modules had significantly cooler substrate temperatures during the summer and significantly warmer temperatures during the fall.  Additionally, the Cladonia modules lost significantly less water than the substrate-only control. This implies that they may be able to benefit neighboring vascular plant species by reducing water loss and maintaining favorable substrate temperatures.

  8. Cladonia lichens on extensive green roofs: evapotranspiration, substrate temperature, and albedo [v2; ref status: indexed, http://f1000r.es/2v4

    Directory of Open Access Journals (Sweden)

    Amy Heim

    2014-01-01

    Full Text Available Green roofs are constructed ecosystems that provide ecosystem services in urban environments. Shallow substrate green roofs subject the vegetation layer to desiccation and other environmental extremes, so researchers have evaluated a variety of stress-tolerant vegetation types for green roof applications. Lichens can be found in most terrestrial habitats.  They are able to survive extremely harsh conditions, including frequent cycles of desiccation and rehydration, nutrient-poor soil, fluctuating temperatures, and high UV intensities. Extensive green roofs (substrate depth <20cm exhibit these harsh conditions, making lichens possible candidates for incorporation into the vegetation layer on extensive green roofs.  In a modular green roof system, we tested the effect of Cladonia lichens on substrate temperature, water loss, and albedo compared to a substrate-only control. Overall, the Cladonia modules had significantly cooler substrate temperatures during the summer and significantly warmer temperatures during the fall.  Additionally, the Cladonia modules lost significantly less water than the substrate-only control. This implies that they may be able to benefit neighboring vascular plant species by reducing water loss and maintaining favorable substrate temperatures.

  9. C2-C6 background hydrocarbon concentrations monitored at a roof top and green park site, in Dublin City centre.

    Science.gov (United States)

    O'Donoghue, R T; Broderick, B M

    2007-09-01

    A 5 week monitoring campaign was carried out in Dublin City centre, to establish which site gave a more accurate background city centre estimation: a roof-top or green field site. This background represented a conservative estimate of HC exposure in Dublin City centre, useful for quantifying health effects related to this form of pollution and also for establishing a local background relative to the four surrounding main roads when the wind direction is travelling towards each road with the background receptor upwind. Over the entire monitoring campaign, the lowest concentrations and relative standard deviations were observed at the green field site, regardless of time of day or meteorological effects.

  10. Understanding green roof spatial dynamics: results from a scale based hydrologic study and introduction of a low-cost method for wide-range monitoring

    Science.gov (United States)

    Hakimdavar, Raha; Culligan, Patricia J.; Guido, Aida

    2014-05-01

    Green roofs have the potential, if implemented on a wide scale and with proper foresight, to become an important supplement to traditional urban water management infrastructure, while also helping to change the face of cities from concrete draped, highly modified environments, to hybrid places where nature is more closely integrated into designs rather than pushed out of them. The ability of these systems to act as a decentralized rainwater handling network has been the topic of many recent studies. While these studies have attempted to quantify the hydrologic performance of green roofs, it's clear that they are dynamic systems whose responses are difficult to generalize. What also seems to be lacking from many studies is a discussion on the effects of green roof scale, spatial planning and configuration. This research aims to understand how rainfall characteristics and green roof scale impact its hydrologic performance. Three extensive green roof systems in New York City, with the same engineered components, age and regional climatic conditions, but different drainage areas, are analyzed. We find that rainfall volume and event duration are two of the parameters that most affect green roof performance, while rainfall intensity and antecedent dry weather period are less significant. We also find that green roof scale does in fact affect hydrologic performance, but mainly in reducing runoff peaks, with rainfall retention and lag time being much less affected by drainage area. We also introduce a low-cost monitoring method, termed the Soil Water Apportioning (SWA) method, which uses a water balance approach to analytically link precipitation to substrate moisture, and enable inference of green runoff and evapotranspiration from information on substrate moisture changes over time. Twelve months of in situ rainfall and soil moisture observations from three different green roof systems - extensive vegetated mat, semi-intensive vegetated mat, and semi-intensive tray - are

  11. Review on the effect of green roofs on quality and quantity of roof runoff%屋顶绿化对屋面径流的影响研究综述

    Institute of Scientific and Technical Information of China (English)

    叶建军; 陈佳捷; 肖衡林; 徐维生; 高林霞; 黄艳雁; 万娟

    2016-01-01

    As an artificial ecosystem,green roofs are an important supplement for urban green system, which can lessen and mitigate many urban ecological and environmental problems.In recent 20 years,green roofs have won some development, but their developing rate is very slow. The main reason is that Chinese people don’t have enough recognition on the improving effect of green roofs on urban environment and ecologi-cal system.Though researchers at home and abroad have achieved consensus on the absorbing and retaining effect of green roofs,on roof runoff and on its lessening urban flood effect,they have controversial views on how green roofs affect the quality of roof runoff.By reviewing the studies on the topic of the effect of green roofs on roof runoff quantity and quality in the past 20 years,the advances and controversies were shown,and the main problems were analyzed and the developing trends in this field were predicted as well.52refs.%屋顶绿化作为城市人工生态系统,是改善城市绿化的补充,能缓解众多城市生态环境的问题.最近20年,虽然屋顶绿化在国内有一些发展,但发展速度十分缓慢,主要问题在于人们对屋顶绿化改善城市生态环境的作用认识不够.虽然国内外学者对于屋顶绿化吸收和截留屋面径流、减轻城市内涝灾害的认识已经取得了一致,但学术界对屋顶绿化怎样影响屋面径流水质还存在争议.通过对最近20年国内外学者在屋顶绿化对屋面径流的水质和水量的影响研究综述,系统介绍了这个领域的进展和争议,分析了存在的主要问题,展望了未来可能的发展方向.参52.

  12. Discussion on technical measures for water saving of roof greening%屋顶绿化节水技术措施的探讨

    Institute of Scientific and Technical Information of China (English)

    杨晓宇

    2014-01-01

    Combined with the specific characteristics of roof greening , hydrophobic layer of water -saving irrigation technology of roof greening and planting area of roof garden structural layer is improved , the reasonable design thoughts solving the roof greening irrigation and drainage problems often meet in the course of designing were put forward .%本文结合屋顶绿化的具体特点,探讨屋顶绿化的节水灌溉技术的选择和屋顶花园种植区构造层中的疏水层改进,对解决屋顶绿化灌溉与排水设计过程中常遇见的问题提出了合理的设计思路。

  13. Aralysis on Thermal Insulation Characteristics of Extensive Green Roofs%粗放型屋顶绿化隔热效果分析

    Institute of Scientific and Technical Information of China (English)

    杨真静; 唐鸣放; 郑澍奎

    2012-01-01

    以自然通风层的屋顶绿化为研究对象,对有无绿化屋顶内表面温度进行比较,采用实测数据统计分析的方法,以全夏季为研究周期,按不同温度区间分析屋顶内表面温度的分布特性,比较2种状态下屋顶内表面温度的分布频率以及总温度,得到绿化屋顶内表面温度<34℃出现的频率占总周期的90%,是无绿化屋顶的1.6倍,大于36℃高温的频率为无绿化屋顶的4.6%,绿化屋顶内表面大于30℃的温度总量约为无绿化屋顶的1/3,且绿化屋顶的隔热性能与室外气温有较强的正向性,随着气温的升高,绿化屋顶的隔热性能体现得更加充分.%Through comparison of internal surface temperature (IST) of green roofs with that without green roofs through field measurement and statistics analysis,green-roof under natural convention climate in summer was analyzed.Distribution frequency and sum of IST under the conditions with and without green roofs were investigated by dividing IST into several ranges.It is shown that the frequency of IST lower than 34 ℃ for green roofs was 90% ,which was about 1.6 times of that for roofs without green.While the frequency of IST exceeding 34 ℃ for green roofs was 4.6% of that for roofs without green,and the sum of 1ST exceeding 30℃ was about 1/3 of that for roofs without greening.Moreover,the property of thermal insulation of green roofs had strong positive relation with outdoor temperature.The thermal insulation characteristic was better as outdoor temperature grew up.

  14. The composition and depth of green roof substrates affect the growth of Silene vulgaris and Lagurus ovatus species and the C and N sequestration under two irrigation conditions.

    Science.gov (United States)

    Ondoño, S; Martínez-Sánchez, J J; Moreno, J L

    2016-01-15

    Extensive green roofs are used to increase the surface area covered by vegetation in big cities, thereby reducing the urban heat-island effect, promoting CO2 sequestration, and increasing biodiversity and urban-wildlife habitats. In Mediterranean semi-arid regions, the deficiency of water necessitates the use in these roofs of overall native plants which are more adapted to drought than other species. However, such endemic plants have been used scarcely in green roofs. For this purpose, we tested two different substrates with two depths (5 and 10 cm), in order to study their suitability with regard to adequate plant development under Mediterranean conditions. A compost-soil-bricks (CSB) (1:1:3; v:v:v) mixture and another made up of compost and bricks (CB) (1:4; v:v) were arranged in two depths (5 and 10 cm), in cultivation tables. Silene vulgaris (Moench) Garcke and Lagurus ovatus L. seeds were sown in each substrate. These experimental units were subjected, on the one hand, to irrigation at 40% of the registered evapotranspiration values (ET0) and, on the other, to drought conditions, during a nine-month trial. Physichochemical and microbiological substrate characteristics were studied, along with the physiological and nutritional status of the plants. We obtained significantly greater plant coverage in CSB at 10 cm, especially for L. ovatus (80-90%), as well as a better physiological status, especially in S. vulgaris (SPAD values of 50-60), under irrigation, whereas neither species could grow in the absence of water. The carbon and nitrogen fixation by the substrate and the aboveground biomass were also higher in CSB at 10 cm, especially under L. ovatus - in which 1.32 kg C m(-2) and 209 g N m(-2) were fixed throughout the experiment. Besides, the enzymatic and biochemical parameters assayed showed that microbial activity and nutrient cycling, which fulfill a key role for plant development, were higher in CSB. Therefore, irrigation of 40% can

  15. Tool to address green roof widespread implementation effect in flood characteristics for water management planning

    Science.gov (United States)

    Tassi, R.; Lorenzini, F.; Allasia, D. G.

    2015-06-01

    In the last decades, new approaches were adopted to manage stormwater as close to its source as possible through technologies and devices that preserve and recreate natural landscape features. Green Roofs (GR) are examples of these devices that are also incentivized by city's stormwater management plans. Several studies show that GR decreases on-site runoff from impervious surfaces, however, the analysis of the effect of widespread implementation of GR in the flood characteristics at the urban basin scale in subtropical areas are little discussed, mainly because of the absence of data. Thereby, this paper shows results related to the monitoring of an extensive modular GR under subtropical weather conditions, the development of a rainfall-runoff model based on the modified Curve Number (CN) and SCS Triangular Unit Hydrograph (TUH) methods and the analysis of large-scale impact of GR by modelling different basins. The model was calibrated against observed data and showed that GR absorbed almost all the smaller storms and reduced runoff even during the most intense rainfall. The overall CN was estimated in 83 (consistent with available literature) with the shape of hydrographs well reproduced. Large-scale modelling (in basins ranging from 0.03 ha to several square kilometers) showed that the widespread use of GRs reduced peak flows (volumes) around 57% (48%) at source and 38% (32%) at the basin scale. Thus, this research validated a tool for the assessment of structural management measures (specifically GR) to address changes in flood characteristics in the city's water management planning. From the application of this model it was concluded that even if the efficiency of GR decreases as the basin scale increase they still provide a good option to cope with urbanization impact.

  16. 屋顶绿化传热临界温度%Indoor Temperature of Green Roof in Heat Transfer Critical State

    Institute of Scientific and Technical Information of China (English)

    唐鸣放; 杨真静; 郑澍奎

    2013-01-01

    Based on the existing experiment, the heat flux characteristics of green roof in passive indoor thermal environment and thermal parameter suitable for evaluation of the thermal performance of green roof were analyzed. It is found that there is indoor critical temperature in acceptable indoor thermal environment range for green roof, in which there is no heat transfer from roof. Through the correlation analysis of internal surface heat flux of roof and the temperature difference between indoor and outdoor, it is shown that the indoor critical temperature is 1. 5℃ lower than air temperature outside for green roof.%根据实验研究结果,分析了屋顶绿化在被动式室内热环境状态下的热流特点.研究结果表明,不能采用等效热工参数评价其隔热性能.采用屋顶绿化实验方法,证明了屋顶绿化在室内人体可接受的热环境范围内存在着不向室内传热的临界温度状态.通过屋顶内表面热流与室内外温差的相关性分析,得出屋顶绿化的传热临界温度低于室外平均气温1.5℃.

  17. 城市绿色屋顶生物栖息生境设计与营建研究%Urban Green Roof Habitat Designing and Construction

    Institute of Scientific and Technical Information of China (English)

    贺坤; 项耿铭; 韦捷峰; 吴威; 章银柯; 李小平

    2015-01-01

    The urbanization process has affected the use of biological habitats.The green roof however,can provide habitats and stepping stones for birds and insects.There exist great potentials for the construction of green roof for the wildlife habitats.Based of the related researches,the relationship between the green roof with wildlife habitats was discussed.The key technologies about the technical process and landscape planning and design of green roof habitat were explained.Furthermore,some examples for the construction of green roof were put forward.%城市化进程影响了生物对栖息地的利用.绿色屋顶具有营建城市野生动物栖息生境的极大潜力,可为鸟类、昆虫等在城市中迁徙提供栖息地和“踏脚石”.在相关研究的基础上,探讨了绿色屋顶与动物栖息生境的关系,从技术流程的构建、景观规划设计等方面阐述了绿色屋顶栖息生境营建的关键技术,并结合研究成果进行了具体的屋顶栖息生境营造实践.

  18. 粗放型屋顶绿化系统的结构与功能%Structure and Function of Extensive Roof Greening

    Institute of Scientific and Technical Information of China (English)

    米文精; 张晋英; 樊兰英

    2012-01-01

    从屋顶绿化的涵义及类型出发,对国内外粗放型屋顶绿化系统的结构和功能进行了论述与分析。从概念推广、经济适用、促进技术规范和吸引政策保障等几方面,阐述了粗放型屋顶绿化在中国发展的开拓性和必要性,指出粗放型屋顶绿化必然被更多的城市纳入规划建设中。%Based on the conception,classification of roof greening,this paper generalized structure,function of extensive roof greening after analyzing the condition of roof greening at home and abroad.Moreover,advantages of spread conception,economy and application and technical assistance as well as policy guarantee in extensive roof greening are described.Development of the pioneering and necessity in extensive roof greening in China are suggested.

  19. 临沂市屋顶绿化研究综述%Exploration and practice of roof greening in the city of Linyi

    Institute of Scientific and Technical Information of China (English)

    党东雨

    2012-01-01

      本文结合临沂市屋顶绿化的发展现状,认真研究了屋顶绿化的类型、佛甲草的特点和佛甲草的管理要求,并对佛甲草屋顶绿化的不同基质进行试验,总结了屋顶绿化的技术工艺,提出了临沂市运用佛甲草进行简单式屋顶绿化的验收标准。%  This article unifies roof greening development present situation in Linyi city, has carefully studied the type of roof greening, characteristics and management requirements of Sedum Lineare and roughly of roof greening experiment with different substrates, summed up the green roof technology, presented a simple green roofs using Sedum Lineare acceptance criteria in the city of Linyi.

  20. Economic and environmental evaluation model for selecting the optimum design of green roof systems in elementary schools.

    Science.gov (United States)

    Kim, JiMin; Hong, TaeHoon; Koo, Choong-Wan

    2012-08-07

    Green-roof systems offer various benefits to man and nature, such as establishing ecological environments, improving landscape and air quality, and offering pleasant living environments. This study aimed to develop an optimal-scenario selection model that considers both the economic and the environmental effect in applying GRSs to educational facilities. The following process was carried out: (i) 15 GRSs scenarios were established by combining three soil and five plant types and (ii) the results of the life cycle CO(2) analyses with the GRSs scenarios were converted to an economic value using certified emission reductions (CERs) carbon credits. Life cycle cost (LCC) analyses were performed based on these results. The results showed that when considering only the currently realized economic value, the conventional roof system is superior to the GRSs. However, the LCC analysis that included the environmental value, revealed that compared to the conventional roof system, the following six GRSs scenarios are superior (cost reduction; reduction ratio; in descending order): scenarios 13 ($195,229; 11.0%), 3 ($188,178; 10.6%), 8 ($181,558; 10.3%), 12 ($130,464; 7.4%), 2 ($124,566; 7.0%), and 7 ($113,931; 6.4%). Although the effect is relatively small in terms of cost reduction, environmental value attributes cannot be ignored in terms of the reduction ratio.

  1. Influence of indoor temperature on equivalent thermal resistance of green roof%室内气温对绿化屋顶当量热阻的影响

    Institute of Scientific and Technical Information of China (English)

    杨真静; 熊珂; 唐鸣放

    2015-01-01

    绿化屋顶在节能设计中以附加当量热阻增大屋顶总热阻值,有效减少由屋顶进入室内的热量,降低室内空气温度。但根据已有的实验研究,绿化屋顶隔热特性与室内气温是耦合关系,随室内气温的变化,绿化屋顶会呈现出不同的隔热特性。用实验测试与数值模拟相结合的方法,分析在不同室内气温下绿化屋顶、参照屋顶与等效保温屋顶内表面温度与热流的变化。结果表明:室内气温会显著改变绿化屋顶的隔热性能,其当量热阻为与室内温度正相关的变量。在被动式建筑中,绿化屋顶更能充分发挥隔热功效,且具有不向室内传热的特性。%Green roof contributes to high total thermal resistance of roof serving as additional equivalent thermal resistance ,which effectively reduces the heat gain from roof and lowers the indoor air temperature . However ,current studies showed that the relationship of indoor temperature and thermal performance was coupling and the performance of the green roof are different with the change of the indoor temperature . Surface temperature and heat flux changes of green roof ,reference roof and equivalent insulating roof were analyzed respectively w hen the indoor temperature changed using both experiment and numerical simulation . The results showed that the indoor temperature had significant impact on the insulation performance of green roof and the equivalent thermal resistance had positive correlationwith the indoor temperature .The insultation performance of green roof reduces heat gain in passive building .Key words :green roof ;equivalent thermal resistance ;numerical simulation .

  2. Sokol Blosser Barrel Aging Cellar : green roofs and LEED{sup TM} buildings in the rural context

    Energy Technology Data Exchange (ETDEWEB)

    Cravens, L.L. [Sera Architects Inc., Portland, OR (United States)

    2004-07-01

    An earth covered structure that stores 900 barrels of wine at the Sokol Blosser Winery located in Yamhill Valley, southeast of Portland, Oregon was presented. The owner's decision to build as sustainably as possible when constructing the barrel aging cellar was reinforced by their involvement in the Oregon Natural Step Network, a non-profit organization that promotes sustainability principles in any endeavor. The sustainable project design solution led by SERA Architects met the winery's requirements for an underground structure capable of storing 900 barrels of wine in three chambers; natural daylight throughout; control over the temperature and humidity; natural ventilation; the use of sustainable materials, and minimal materials; use of local products; preserving the maximum existing open area; and, minimizing construction demolition and waste. The Leadership in Energy and Environmental Design (LEED) criteria for the green building rating system was used to measure the green construction practices. The many benefits of burying the building were identified, namely the cooling system was eliminated, which reduced the cost of the mechanical system, reduced the major draw for energy, and eliminated any use of ozone depleting refrigerants. The roof's waterproofing system was provided by Tremco. Combined with a non-engineered earth cover the manufacturer provided a warranty of 20 years but predicted a 60 year life for the roof. The Roof sandwich structure from top down was described in detail and illustrations were presented. The final calculations indicate a $750 annual energy savings above a traditional space. 6 figs.

  3. Research Development in Water Quality Monitoring of Green Roof Runoff%绿色屋顶径流水质监测研究进展

    Institute of Scientific and Technical Information of China (English)

    罗鸿兵; 刘瑞芬; 邓云; 张可; 刘晓玲; 申琼; 黄波; 莫忧

    2012-01-01

    概述了国内外绿色屋顶径流水质监测发展状况,并从绿色屋顶径流收集、降雨场次、监测指标、径流水质和污染物传输的影响因子等方面进行了归纳和总结.基于水量和水质管理,从几何尺寸、土壤类型和厚度、植被和维护等方面阐述了绿色屋顶在城市排水系统中的作用和地位.揭示了绿色屋顶需要开展长期的监测和研究,绿色屋顶径流水质监测逐渐向采样自动化和分析自动化方向发展.%Research development in runoff water quality monitoring of green roof was reviewed such as runoff water collected from green roof, number of rainfall, monitoring items, runoff water quality, impact factor of pollutant transmission, etc. Based on water quantity and water quality management, role of green roof in urban drainage system was descried including shape and size of green roof, features and thickness of soils, protection and maintain of vegetation, etc. It needs a long-term monitoring and research to know function of green roof. Development direction would be sampling and analysis automation for runoff water quality monitoring of green roof.

  4. Impact of Green Roof and Orientation on the Energy Performance of Buildings: A Case Study from Saudi Arabia

    Directory of Open Access Journals (Sweden)

    Hassan Saeed Khan

    2017-04-01

    Full Text Available Saudi Arabia is one of the largest countries in the Middle East region in terms of population, geographic area and scale of economy. It has a fast growing energy sector with over 76% of the total electricity being consumed in the building sector. Domestic buildings account for 51% of total electricity consumption. Predominantly due to hot climatic conditions, most of the energy consumption in buildings is attributed to the heating, ventilation and air conditioning (HVAC loads. In terms of supply mix, the country entirely relies on oil and gas to meet its energy requirements. The high growth in energy demand is imposing stringent energy, environmental and economic challenges for Saudi Arabia. The present work aims to explore prospects of energy saving in buildings through the application of green roof technology. With the help of ECOTECT modelling, the work examines the effectiveness of green roof on considering modern faculty homes built in the King Fahd University of Petroleum and Minerals situated in the hot-humid climatic conditions of the Easter Province of the country. The same building has also been investigated for the hot-dry climate of Riyadh, the capital city. The work also examines the impact of orientations on the energy performance of buildings.

  5. 绿化屋顶热效应的观测试验%Experimental study of the thermal performance of a green roof

    Institute of Scientific and Technical Information of China (English)

    孙挺; 倪广恒; 唐莉华; 张书函; 孔刚

    2012-01-01

    为了评价绿化屋顶对城市微环境的热效应影响,利用基于轻质高透水性基质材料的绿化屋顶和普通屋顶,开展了近10个月对比观测,对温度、热阻值(R值)等进行了定量分析。结果显示:观测期内绿化屋顶的屋面温度波动降低54%,在秋、冬和春季表现出保温效果,夏季则表现出降温效果,并将屋顶整体热阻值提高33%~200%。绿化屋顶对降低建筑能耗、改善人居环境具有积极作用。%The thermal impact on the urban microenvironment of a lightweight aggregate-based green roof was studied by parallel experiments for 10 months to observe the temperatures and estimate the R-value of both green and conventional roofs.During the experimental period,the green roof significantly reduced temperature fluctuations by 54%,provided effective thermal insulation in the winter,protected the roof membrane from rapid heating in the summer,and increased the R-value of the ensemble roof system by 33%~200%.The results show that the green roof is capable of protecting the roof system from extreme temperatures and improving the urban microclimate.

  6. 浅谈地下停车场的顶板绿化%Study on the Roof Greening of Underground Parking

    Institute of Scientific and Technical Information of China (English)

    罗利娟

    2011-01-01

    By analyzing the current situation and problems about the roof greening of underground parking, the au- thor pointed out that the roof greening should be designed according to load. In addition, it is also necessary to deal with waterproof, drainage proce%本文通过分析当前地下停车场顶板绿化的现状及存在问题,指出地下停车场顶板的绿化应根据荷载进行设计,做好防水、排水处理及植物品种选择。

  7. 北京通惠家园小区屋顶绿化设计评析%The green roof design of Beijing Tonghuijiayuan village

    Institute of Scientific and Technical Information of China (English)

    孙颖; 吴晖晗; 李爱芳; 韩丽霞; 车冠宇

    2015-01-01

    Taking Tonghuijiayuan community roof greening in Beijing as an example,the paper respectively carries out questionnaire for internal community residents,community managers and partial community surrounding residents,know about various users’demands for roof greening and design defects,and analyzes residential roof greening design concept,integral layout and greening design and other contents,with a view to explore new community roof greening design concepts in Beijing city.%以北京通惠家园小区屋顶绿化为实例,分别对小区内居民、小区管理者及小区周边居住区的部分居民进行了问卷访谈调研,了解了不同层面的使用者对于屋顶绿化的需求及其在设计上的不足,探析了居住区屋顶绿化的设计理念、整体布局、绿化设计等方面内容,旨在为北京市居住区屋顶绿化设计探索新思路。

  8. Research and Thinking on the Roof Greening in Beijing%北京地区屋顶绿化研究与思考

    Institute of Scientific and Technical Information of China (English)

    曾慧子; 李运远

    2015-01-01

    本文介绍了北京市屋顶绿化近年来的发展状况,并分别对两类屋顶绿化,即简单式屋顶绿化和花园式屋顶绿化进行分析,总结归纳这两类屋顶绿化的设计特征与要点,旨在为其他屋顶花园的建造提供有益的参考。文章的最后探讨了屋顶花园的发展可能与趋势,提出了屋顶花园设计与营造的新思路、新方法。%This article introduced the development of roof greening in recent years of Beijing, analyzed and summarized design character and points about two roof greening types, they are simple roof garden and garden roof garden, aimed at providing some useful reference. At last, discussed the tendency and possibility of roof greening, raised the new ideas and methods.

  9. 重庆市屋顶绿化的降温增湿效应%The Ecological Effects of Roof Greening in Chongqing

    Institute of Scientific and Technical Information of China (English)

    吴志能; 邹敏; 陈祥; 艾丽皎; 先旭东

    2015-01-01

    选择在植物降温作用最为明显的夏季,以重庆市不同屋顶绿化类型为研究对象,比较研究简单式和花园式屋顶绿化的降温增湿效应。结果表明,简单式屋顶绿化、花园式屋顶绿化对室内温度的平均降温程度分别为1.75℃、4.35℃;与无绿化屋顶相比,简单式、花园式屋顶绿化对屋顶环境的平均降温程度分别为2.55℃、9.81℃,增湿效果分别为5.01%、21.19%,降低地表温度的程度分别为7.93℃、18.14℃。表明屋顶绿化具有显著的降温增湿效应。%This paper take different roof greening in Chongqing as research object ,and choose the most obvious plant effect season summer as research time ,so as to compare the cooling and humidifying effects of simple and garden roof greening modes .The results show that simple roof greening and garden roof greening′s average temperature indoor is 1.75 ℃and 4.35 ℃respectively;compared with blank roof ,simple roof greening and garden roof greening′s cooling degree is 2.55 ℃,9.81 ℃respectively ,and the humidifying effects are 5.01%,21.19%;the sample and garden roof greening′s cooling degree of the surface temperature is 7.93 ℃and 18.14℃respectively.The results indicate that green roofs have significant ecological effect .

  10. 浅谈屋顶绿化的植物选择——以广西森林资源保护中心屋顶绿化方案为例%The Selection of Plants for Roof Greening --A Case Study of Roof Greening Plan in Guangxi Forest Resources Conservation Center

    Institute of Scientific and Technical Information of China (English)

    韦庆锋

    2012-01-01

    In modern cities, in order to increase the green area and improve the urban environment, the roof greening program is rising gradually. By analyzing the facing problems combined with the cas- es of roof greening, the selection of plants for roof greening were studied.%在现代城市中,为了增加绿化面积,改善城市环境,逐渐兴起了屋顶绿化工程。针对屋顶绿化在植物选择时所面临的问题,结合屋顶绿化实例进行分析,探讨屋顶绿化时的植物选择。

  11. Differential substrate subsidence of the EnviHUT project pitched extensive green roof

    OpenAIRE

    Nečadová Klára; Selník Petr; Karafiátová Hana

    2017-01-01

    In primary phase of testing building physical characteristics of the EnviHUT project extensive and semi-intensive roofs with 30° inclination occurred exceptional substrate subsidence. An extensive testing field with retaining geocell-system evinced differential subsidence of individual sectors after six months. Measured subsidence of installed substrate reached 40 % subsidence compared to originally designed height (intended layer thickness). Subsequent deformation of geocell-system additiona...

  12. Reprint of “Moisture content behaviour in extensive green roofs during dry periods: The influence of vegetation and substrate characteristics”

    Science.gov (United States)

    Berretta, Christian; Poë, Simon; Stovin, Virginia

    2014-08-01

    Evapotranspiration (ET) is a key parameter that influences the stormwater retention capacity, and thus the hydrological performance, of green roofs. This paper investigates how the moisture content in extensive green roofs varies during dry periods due to evapotranspiration. The study is supported by 29 months continuous field monitoring of the moisture content within four green roof test beds. The beds incorporated three different substrates, with three being vegetated with sedum and one left unvegetated. Water content reflectometers were located at three different soil depths to measure the soil moisture profile and to record temporal changes in moisture content at a five-minute resolution. The moisture content vertical profiles varied consistently, with slightly elevated moisture content levels being recorded at the deepest substrate layer in the vegetated systems. Daily moisture loss rates were influenced by both temperature and moisture content, with reduced moisture loss/evapotranspiration when the soil moisture was restricted. The presence of vegetation resulted in higher daily moisture loss. Finally, it is demonstrated that the observed moisture content data can be accurately simulated using a hydrologic model based on water balance and two conventional Potential ET models (Hargreaves and FAO56 Penman-Monteith) combined with a soil moisture extraction function. Configuration-specific correction factors have been proposed to account for differences between green roof systems and standard reference crops.

  13. On Application of Modularized Landscape in Roof Greening%浅谈模块化景观在屋顶绿化中的应用研究

    Institute of Scientific and Technical Information of China (English)

    刘启明; 曹馨妍

    2016-01-01

    This article starts from the social and economy background of roof garden application, analyzes several aspects of landscape module facilities, including the selection and configuration, material and pavement, planting design and application effect, and innovatively transforms the design of traditional green roof. By applying the existing new energy technologies to roof greening and modularize the landscape, a roof garden greening system, which is green, ecological, self -maintained, and has cycle capabilities, could be formed.%从应用屋顶花园的社会背景和经济背景入手,从模块化景观设施的选择与配置、选材铺装、植栽设计以及应用效果几个方面进行分析,将传统屋顶绿化的设计进行创新性改造。在屋顶绿化中运用已有的新能源技术,通过模块化的景观处理,形成绿色、生态、能够自我维护并具有循环能力的屋顶花园绿化系统。

  14. 居住区棚架式屋顶绿化形式探讨%Discussion on shelf roof greening at residential areas

    Institute of Scientific and Technical Information of China (English)

    林秋桂; 陶萌春

    2016-01-01

    Roof greening can compensate for the natural plants occupied by buildings and improve the building energy efficiency. The collection and using of rainwater can solve the water utilization for afforestation. The text explores a kind of potted shelf roof greening suitable for Fuzhou residents and its main technologies by talking about the significance of roof greening to the city construction, research status and the existing problems in the roof greening.%屋顶绿化可以补偿被建筑占据的地面上的自然植被,提高建筑节能性,雨水收集利用能解决绿化用水问题。文章通过阐述屋顶绿化对城市建设的意义,以及福州地区屋顶绿化研究现状和存在的问题,探讨一种适宜福州地区居住区屋顶的盆栽棚架式绿化形式与其主要技术。

  15. Selection of Indigenous Plants for Roof Greening in Chengdu%乡土植物在成都市屋顶绿化中的选择

    Institute of Scientific and Technical Information of China (English)

    张媛; 沈一

    2011-01-01

    简要介绍成都市屋顶绿化工作的发展情况及其意义,从探讨成都市屋顶绿化现状出发,指出在选择屋顶绿化植物时,应考虑乡土植物的应用,并根据屋顶绿化植物的选择标准以及成都市乡土植物种类名录,为成都市乡土植物在屋顶绿化中的运用提供参考.%The development of roof greening in Chengdu and its significance were introduced briefly. By discussing its current situation, the author pointed out that the indigenous plants should be taken into consideration when it came to the selection of roof greening materials. Moreover, based on the selection criteria of roof greening plants and the species category of indigenous plants in Chengdu, this article offered references for the application of indiyenous plants in roof greening in Chengdu.

  16. Contributions to the design of rainwater harvesting systems in buildings with green roofs in a Mediterranean climate.

    Science.gov (United States)

    Monteiro, Cristina M; Calheiros, Cristina S C; Pimentel-Rodrigues, Carla; Silva-Afonso, Armando; Castro, Paula M L

    2016-01-01

    Green roofs (GRs) are becoming a trend in urban areas, favouring thermal performance of buildings, promoting removal of atmospheric pollutants, and acting as possible water collection spots. Rainwater harvesting systems in buildings can also contribute to the management of stormwater runoff reducing flood peaks. These technologies should be enhanced in Mediterranean countries where water scarcity is increasing and the occurrence of extreme events is becoming very significant, as a result of climate change. An extensive pilot GR with three aromatic plant species, Satureja montana, Thymus caespititius and Thymus pseudolanuginosus, designed to study several parameters affecting rainwater runoff, has been in operation for 12 months. Physico-chemical analyses of roof water runoff (turbidity, pH, conductivity, NH4(+), NO3(-), PO4(3-), chemical oxygen demand) have shown that water was of sufficient quality for non-potable uses in buildings, such as toilet flushing. An innovative approach allowed for the development of an expression to predict a 'monthly runoff coefficient' of the GR system. This parameter is essential when planning and designing GRs combined with rainwater harvesting systems in a Mediterranean climate. This study is a contribution to improving the basis for the design of rainwater harvesting systems in buildings with extensive GRs under a Mediterranean climate.

  17. Humble Opinion of Roof Gardens

    Institute of Scientific and Technical Information of China (English)

    WANGXiaoxiao; MAQiangqiang; CAOXiaojun

    2005-01-01

    With the swift development of urban construction in China and the boost in people's demands for green environments in cities, roof gardens are widely used as a new way of greening. This paper deals chiefly with the functions, building principle, classification and composing elements of roof gardens, an analysis of main ecological factors, loads, and waterproof. It suggests that roof gardens will bring about a comparatively big leap in city greening both quantitatively and qualitatively.

  18. 复合功能植被顶板集成创新技术研究%Research on innovation technology of green roof compound system integration

    Institute of Scientific and Technical Information of China (English)

    邵军义; 宗晶

    2013-01-01

    建筑顶板上设计种植绿化是目前城市建筑的普遍方法,人防地下室(车库)复合功能植被顶板环境复杂,需要满足抗腐蚀、防植物根刺、防水保护、快速排水等要求.因此为确保复合功能植被顶板的系统安全,必须考虑提高工程质量.针对复合功能植被顶板易出现的质量问题进行研究,提出解决措施,并通过工程实例进行经济、社会效益分析.%It's a common practice of planting virescence on the building roof.The complexity of green roof compound system must be satisfied for the corrosion resistance,root penetration resistance,waterproof protection,fast-draining and many other technical standards.In order to ensure green roof compound system safe to use,we should improve the green roof compound system quality.This paper is mainly focus on analysis and exploration of the construction techniques and some quality problems easily occur in the construction and some control measures.Finally,analyze social benefit and economic benefit through an engineering example.

  19. The green roof design of residential underground garage%住宅小区地下车库屋顶绿化设计

    Institute of Scientific and Technical Information of China (English)

    焦云祥; 殷慧

    2015-01-01

    Taking the roof greening of Taiyuan“Lake View One”residential area underground garage for example,combining with the relevant theoretical basis,this paper discussed the planning and design,technology,ways and methods,construction planting of residential underground garage roof greening,pointed out that the rise of roof greening this building form provided new construction space for increasing the amount of greening green,beautifying the urban.%以太原市“湖景壹号”住宅区地下车库屋顶绿化为例,结合相关理论基础,对住宅区地下车库屋顶绿化的规划设计、技术、方式方法、施工种植进行了探讨,指出屋顶花园这一建设形式的兴起,为增加城市绿化,美化城市提供了新的建设空间。

  20. Empirical Analysis on Cost and Energy Saving Benefits of Roof Greening%屋顶绿化成本及节能效益实证分析

    Institute of Scientific and Technical Information of China (English)

    方眠; 张雁; 王幼松; 黄亚男

    2015-01-01

    既有屋顶适当绿化可增大城市绿化面积,也能起到室内隔热降温的作用,还具有改善城市空气质量、缓解热岛效应等功能.鉴于其绿化技术、维护成本、节能效益及经济效益方面存有争议,以广州为例,分析研究屋顶绿化的成本和效益,并指出其社会效益和环境效益显著,为大力推广提供依据.%Green roof can increase the green area of the city,can also play an important role in indoor heat insulation and cooling,as well as improve quality of the city air and reduce the greenhouse effect. But there is much debate about greening technology,the cost of maintenance and energy saving and economic benefits at present. This paper selects Guangzhou as an example,using the method of energy saving-benefit analysis and cost-benefit analysis to analyze the cost and benefits for roof greening. The results show that the social benefits and environmental benefits of roof greening is significant,and as a result it's worth promoting.

  1. Study on the Water-holding Characteristics of Light Matrix for Green Roof%绿化屋顶轻量基质持水特性研究

    Institute of Scientific and Technical Information of China (English)

    吕华芳; 唐莉华; 孙挺; 陈建刚

    2011-01-01

    绿化屋顶具有减缓雨洪、调节局部气候、净化环境等功能,在国内外各大城市得到广泛应用。轻量基质是绿化屋顶普遍采用的代替天然土壤的种植层基质,是屋顶水分涵养、植物生长的主要载体。有关轻量基质的持水性能研究目前尚不多见。结合在北京市某大学办公楼楼顶平台所建的绿化屋顶示范区,对种植层轻量基质的持水特性进行了相关试验,得出了表征其持水性能的相关参数,并用示范区气象和水分自动观测数据对试验测得的基质持水特性进行了验证,结果表明:绿化屋顶所用的轻量基质容重远低于普通土壤,而持水效果很好。该文研究成果可为绿化屋顶的水热规律%Green roofs have been widely used in major cities all over the world for their function of reducing flood,regulating local climate and cleaning up environment.Instead of natural soil,light matrix is usually used as planting layer on green roofs.At present,there is little study on water-holding characteristics of such material.In this paper,combined with a plot of green roof build up on the top floor of an office building in a university in Beijing,some experiments on the water-holding characteristics of matrix were carried out.Some other characteristics of water content were also tested and verified by the experiments and data on green roof were automatically observed.According to the experimental results,it was obtained that the material used in the green roof is much slighter than natural soil,but with great water-holding capacity.The research results can provide basic references for deeply analyzing water and heat energy,as well as application and promotion of green roofs.

  2. 浅谈推广城市屋顶绿化的对策建议%Suggestions and countermeasures of the urban roof greening promotion

    Institute of Scientific and Technical Information of China (English)

    张帆; 王雪芬; 应求是

    2016-01-01

    在城市快速发展与扩张的同时,随之而来的环境污染问题也愈加严重,为了有效改善城市环境,提高城市居民的生活质量,就需要在有限的城市空间中加大绿量,而屋顶绿化是一个切实有效的解决办法。但是屋顶绿化目前尚未在城市发展中有效推广,本文分析了屋顶绿化推广的制约因素,阐述了推广城市屋顶绿化对策及建议,以期为相关研究与实践提供借鉴与参考。%With the rapid development and expansion of city,environmental polution problem is becoming more and more serious,in order to improve the urban environment and raise the life quality of urban residents effectively,increasing the amount of green in the limited urban space is necessary and the roof greening is just a practical and effective solution.But the roof greening has not been proposed in the urban development,in this paper,factors of the restriction to the roof greening promotion analyzed,countermeasures and suggestions on the popularizationof the urban roof greening is discussed,so as to offer reference for the related research and practice.

  3. The Development Direction of Xi'an Roof Greening%浅析西安屋顶绿化的发展方向

    Institute of Scientific and Technical Information of China (English)

    王泽瑾; 伏圣丰

    2014-01-01

    Taking Xi'an as an example, in order to improve the environmental quality of Xi'an, should increase the pro-motion of green roofs, considering its features of many uni-versities, many national units, and family member courtyards strewn, the green roof construction should develop from three aspects vigorously.%以西安为例,为了更好改善西安的环境质量,应加大屋顶绿化的推广,考虑其高校林立,有众多国家单位,并且家属院遍布的特点,屋顶绿化建设应从三个方面进行大力发展。

  4. 对我国城市建筑物屋面绿化的效益分析%Analysis on Benefits of Roof Greening for Chinese Urban Buildings

    Institute of Scientific and Technical Information of China (English)

    王亮; 申玲; 杜博

    2011-01-01

    简要叙述了我国城市建筑物屋面绿化技术的发展现状,对屋面绿化的经济效益、生态环境效益和节能效益进行了详细分析,并提出了提高屋面绿化效益的对策与措施.%The development status of roof greening technology for our urban buildings was briefly introduced, and then the economic benefits, eeo-environmental efficiency and energy-saving benefits were analyzed in detail, finally some measures were proposed to improve the benefits of roof greening.

  5. Study on the Application of the Groundcover Plants in the Roof Greening:Setting Roof Greening Projects Surrounding the Yellow Crane Tower of Wuhan City as an Example%地被植物在屋顶绿化中的运用——以武汉市武昌区黄鹤楼周边屋顶绿化项目为例

    Institute of Scientific and Technical Information of China (English)

    陈杰; 龚颖; 闫森

    2012-01-01

    城市的生态化是后工业时代对城市综合功能提出的必然要求,屋顶绿化的发展已成为趋势.园地制宜、有针对性地分选择绿化植物是屋顶绿化建设成败的关键.该文章结合黄鹤楼周边屋顶绿化工程,认为可以通过对地被植物的合理配置以及控制性的造景,使屋顶绿化获得理想的景观效果和生态效应.%The ecological development is an inevitable request of comprehensive urban function in the post-industrial era. The roof greening is becoming a trend of modern times. The application of the right plants according to the specific local conditions is crucial to the success of the green roof construction. Combined with the roof greening projects surrounding the Yellow Crane Tower, the article puts forward that the rational allocation of groundcover plants and the controlled landscaping can make both ideal landscape and ecological effects of the roof greening.

  6. Simulation of green roof runoff under different substrate depths and vegetation covers by coupling a simple conceptual and a physically based hydrological model.

    Science.gov (United States)

    Soulis, Konstantinos X; Valiantzas, John D; Ntoulas, Nikolaos; Kargas, George; Nektarios, Panayiotis A

    2017-09-15

    In spite of the well-known green roof benefits, their widespread adoption in the management practices of urban drainage systems requires the use of adequate analytical and modelling tools. In the current study, green roof runoff modeling was accomplished by developing, testing, and jointly using a simple conceptual model and a physically based numerical simulation model utilizing HYDRUS-1D software. The use of such an approach combines the advantages of the conceptual model, namely simplicity, low computational requirements, and ability to be easily integrated in decision support tools with the capacity of the physically based simulation model to be easily transferred in conditions and locations other than those used for calibrating and validating it. The proposed approach was evaluated with an experimental dataset that included various green roof covers (either succulent plants - Sedum sediforme, or xerophytic plants - Origanum onites, or bare substrate without any vegetation) and two substrate depths (either 8 cm or 16 cm). Both the physically based and the conceptual models matched very closely the observed hydrographs. In general, the conceptual model performed better than the physically based simulation model but the overall performance of both models was sufficient in most cases as it is revealed by the Nash-Sutcliffe Efficiency index which was generally greater than 0.70. Finally, it was showcased how a physically based and a simple conceptual model can be jointly used to allow the use of the simple conceptual model for a wider set of conditions than the available experimental data and in order to support green roof design. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. 绿化屋顶技术研究综述与探讨%Review and Outlook for Construction Technology of Green Roofs

    Institute of Scientific and Technical Information of China (English)

    杨真静; 唐鸣放

    2012-01-01

    在全球气候变暖的趋势下,绿化屋顶作为一种有效的生态措施,对缓解城市区域热环境,改善建筑微气候有积极的作用,国内外学者从不同角度对绿化屋顶做了大量研究.总结了近年来国内外绿化屋顶的发展现状,分析绿化屋顶技术存在的问题及未来的发展方向,并对后续研究提出建议.%With the global warming, as a valid ecological measure, green roofs play a positive role in alleviating city regional thermal environment and improving the micio-climate of buildings. Foreign and domestic scholars have made a great deal of research on the construction of green roofs from different perspectives. This paper summarizes the development of green roofs both at home and abroad in recent years, analyses problems and tendency of the technology, and puts forward suggestions for similar

  8. The Technology of Pumping Light-weight Substrate for Roof Greening%泵送轻质屋顶绿化基材技术

    Institute of Scientific and Technical Information of China (English)

    叶建军; 韦书勇

    2009-01-01

    Rooof greening is the key measure to improve urban environment. Firstly,this paper analyzes the mommonly used technology solutions in roof greeing, and introduces some details on material selection for each layers and the existing problems in the technology of extensive green roofs.Then ,based on the above, this paper presents a new patented technology--the technology of pumping light-weight substrate for roof greening, fo-cusing on the substrate compositions and construction techniques.%屋顶绿化是改善城市环境的关键举措,本文分析了屋顶绿化的常见形式,介绍了简单屋顶绿化形式各层的材料特点、现有的简单屋顶绿化技术方案及存在的问题.在此基础上,论文介绍了一种新发明技术-泵送轻质屋顶绿化基材技术的材料组成和施工.

  9. 屋顶绿化工程防渗漏的优化设计探讨%On exploration for optimized design for anti-leakage of roof green project

    Institute of Scientific and Technical Information of China (English)

    向欣

    2012-01-01

    The paper analyzes the reasons for the roof leakage caused by the roof green project, points out the optimized design scheme in the construction according to the results caused by various reasons, solves the safety and roof anti-leakage problems of the roof structure, so it pro- vides direction for the development of the roof green projects.%对屋面绿化工程所造成的屋顶渗漏产生的原因进行了分析,并针对不同原因造成的后果提出在构造过程中可进行优化设计的方案,解决了屋顶构造安全问题、屋顶防漏问题,为屋顶绿化工程的发展提供指导。

  10. Practical application of methanol-mediated mutualistic symbiosis between Methylobacterium species and a roof greening moss, Racomitrium japonicum.

    Directory of Open Access Journals (Sweden)

    Akio Tani

    Full Text Available Bryophytes, or mosses, are considered the most maintenance-free materials for roof greening. Racomitrium species are most often used due to their high tolerance to desiccation. Because they grow slowly, a technology for forcing their growth is desired. We succeeded in the efficient production of R. japonicum in liquid culture. The structure of the microbial community is crucial to stabilize the culture. A culture-independent technique revealed that the cultures contain methylotrophic bacteria. Using yeast cells that fluoresce in the presence of methanol, methanol emission from the moss was confirmed, suggesting that it is an important carbon and energy source for the bacteria. We isolated Methylobacterium species from the liquid culture and studied their characteristics. The isolates were able to strongly promote the growth of some mosses including R. japonicum and seed plants, but the plant-microbe combination was important, since growth promotion was not uniform across species. One of the isolates, strain 22A, was cultivated with R. japonicum in liquid culture and in a field experiment, resulting in strong growth promotion. Mutualistic symbiosis can thus be utilized for industrial moss production.

  11. 绿色屋顶的雨水管理效能研究%A Study of Green Roof Efficiency in Rainwater Management

    Institute of Scientific and Technical Information of China (English)

    王敏

    2011-01-01

    This paper discussed the basic constituents of green roof"for rainwater management, analyzed" factors affecting green roof efficiency in rainwater management, and thus put forward several design strategies from the perspective of optimizing the efficiency%文中讨论了绿色屋顶的雨水管理基本构成,分析了影响屋面雨水管理效能的各种因素,并从效能优化的角度提出了相应的设计策略。

  12. 天泉生态屋顶绿化技术在“海绵城市”建设中的应用--以湘江新区交通枢纽中心屋顶绿化工程为例%Application of Tianquan Ecological Roof Green Technology in Construction of “Sponge City”--Taking the Roof Greening Project of the Traffic Hub in Xiangjiang New District as An Example

    Institute of Scientific and Technical Information of China (English)

    张翼维; 马攀; 陈善湘; 李尝君; 杨剑华

    2016-01-01

    Taking the roof greening project of the traffic hub in Changsha Xiangjiang New District as an example, introduced the application situation of Tianquan ecological roof green patent technology. The technology took the non-soil ecological substrate and the drought tolerant plant as the carrier, applied prevent leakage, anti-root isolation, water retention, light substrate, vegetation and so on as one to the urban roof greening. Practice showed that the technology can increase the storage capacity 36~50 L/m2, can make the interior of the building an average temperature drop 2~3℃, save the power consumption of air conditioner is 20%~40% at the same time, have the signiifcant effect on the reduction of the urban water resources, peak shaving, and recycling, there is a good application prospects in the construction of“sponge city”.%以长沙湘江新区交通枢纽中心屋顶绿化工程为例,介绍了天泉生态屋顶绿化专利技术的应用情况。该技术以无土生态基质和耐旱耐贫瘠植物为载体,将防渗、隔离防根、保水、轻型基质、植被等合为一体应用于城市屋顶绿化。实践表明:该技术可增加储水量36~50 L/m2,可使建筑内部平均降温2~3℃,同时节约空调耗电量20%~40%,对城市水资源的减流、削峰、再利用效果显著,在“海绵城市”建设中具有较好的应用前景。

  13. THE INFLUENCE THE EXTENSIVE GREEN ROOFS ON THE OUTFLOW RAINWATER TO THE SEWAGE SYSTEM

    OpenAIRE

    Maciej Mrowiec; Małgorzata Sobczyk

    2015-01-01

    In times of rapid urbanization and climate change has drawn more attention to stormwater runoff to sewer systems. The phenomenon of flooding in urban areas have become increasingly common as a result of heavy rains. Sewage systems in such a short time are not able to accept such a large amount of rainwater flowing on the site, which we experience the phenomenon of rainfall flowing down the street in excessive amounts. The problem of such phenomena can be solved by the development of green roo...

  14. On some problems should pay attention to Xi'an development roof greening%西安市发展屋顶绿化应注意的若干问题

    Institute of Scientific and Technical Information of China (English)

    宋小林; 黄璞; 田驰

    2012-01-01

    介绍了西安地区的气候特征和西安城区屋顶的建筑形制,详细分析了西安屋顶绿化建设的可行性,并提出了西安屋顶绿化应该注意的问题,为西安屋顶绿化的普及提供了理论方法依据。%This paper introduced the climate features of Xi'an area and the construction system of Xi'an city roofs,detailedly analyzed the feasibility of Xi'an roof greening construction,and proposed the problems should be paid attention to Xi'an roof greening,provided theory basis to the popularization of Xi'an roof greening.

  15. PREDICTING THERMAL PERFORMANCE OF ROOFING SYSTEMS IN SURABAYA

    OpenAIRE

    2015-01-01

    Traditional roofing systems in the developing country likes Indonesia are still be dominated by the 30o, 45o, and more pitched angle roofs; the roofing cover materials are widely used to traditional clay roof tiles, then modern concrete roof tiles, and ceramic roof tiles. In the 90’s decay, shop houses are prosperous built with flat concrete roofs dominant. Green roofs and roof ponds are almost rarely built to meet the sustainable environmental issues. Some tested various roof systems in Sura...

  16. Analysis on the thermal insulation performance of green roof%植被屋面隔热性能对比测试分析

    Institute of Scientific and Technical Information of China (English)

    杨晚生; 谢儒强

    2012-01-01

    在夏季自然气候条件下对植被屋面和无植被对比屋的面隔热性能进行了测试,通过分析测试数据,获得了屋面内表面温度分布特征、温度波的衰减性、屋面内表面与室外空气温度的关联性以及植被屋面各构造层的衰减性等相关隔热性能参数,并对其进行了对比评价分析,为其在实际工程应用提供了实验依据.%In summer,an experiment test was conducted under natural climatic conditions, comparing the thermal insulation performance between the green roof mom and normal roof room. And by analyzing the data of the experiment test, some parameters of the thermal] insulation ean be identified, such as the distribution characteristics of internal surface temperature,attenuation of temperature wave, the correlation between internal surface temperature and outdoor air temperature as well as the attenuation of the structural layers of green roof providing the experimental basis for practical engineering applications through comparing and evaluating those parameters.

  17. Measuring investigations of the hygrothermal behaviour of timber flat roofs - Part 2: Non-ventilated green roofs with cellulose and mineral wool insulation; Messtechnische Analyse flachgeneigter hoelzerner Dachkonstruktionen mit Sparrenvolldaemmung - Teil 2: Nicht belueftete, extensiv begruente Daecher mit Zellulose- und Mineralwolledaemmung

    Energy Technology Data Exchange (ETDEWEB)

    Nusser, Bernd; Teibinger, Martin [Holzforschung Austria, Wien (Austria); Bednar, Thomas [Forschungsbereich fuer Bauphysik und Schallschutz, TU Wien (Austria)

    2010-08-15

    In the second part of this article serial the measuring values of two green roof elements made of mineral wool insulation with a moisture adaptive vapour retarder and cellulose insulation with a fibrous vapour retarder are discussed. It is shown that the roof surface temperature, beside the weathering conditions, depends on the level of plant coverage. Because of very low drying potential of green roofs high air humidity occurs in the cavity. This leads to higher material moisture content in the element with mineral wool insulation. The green roof element with cellulose insulation shows this higher material moisture content less pronounced. Despite high moisture loads in the cavities of both green roof elements no mould or rot could be found in the investigated roofs. [German] Im gegenstaendlichen zweiten Teil dieser Aufsatzreihe werden die Messwerte aus zwei Gruendachelementen, welche zum einen mit Mineralwolledaemmung und feuchteadaptiver Dampfbremse und zum anderen mit Zellulosedaemmung und Vliesdampfbremse ausgefuehrt sind, diskutiert. Dabei zeigt sich, dass die Temperatur auf der Dachabdichtung neben den Witterungsbedingungen auch vom Bewuchsgrad des Gruendaches abhaengt. Aufgrund der geringen sommerlichen Umkehrdiffusion der Gruendaecher kommt es zu erhoehten Luftfeuchten im Gefach. Dies fuehrt beim Gruendach mit Mineralwolledaemmung zu erhoehten Materialfeuchten. Das Gruendach mit Zellulosedaemmung weist diese erhoehten Materialfeuchten hingegen weniger stark auf. Trotz der teilweise lang andauernden hohen Feuchtelast im Gefach der beiden Gruendaecher konnten weder Schimmel- noch holzzerstoerende Pilze in diesen entdeckt werden. (Abstract Copyright [2010], Wiley Periodicals, Inc.)

  18. Review and Prospect on the Development of Roof greening%屋顶绿化发展的回顾与展望*

    Institute of Scientific and Technical Information of China (English)

    倪国平; 张艳

    2013-01-01

    Being able to make full use of city space,increase city's green area and improve city's ecological environment,roof greening has be-come an important part of urban garden greening.The shortcomings in the policy,technology,and funds were pointed out by analyzing the development history,the plant selection,the seeding matrix,the construction factors and the maintenance management on roof greening. Based on the suceessful experience of developed countries and the national conditions and reality,the state should formulate and perfect the corresponding laws and regulations,and raise funds from government,developers and proprietors.Besides,the country should strengthen the talent training in the field of roof greening and open related courses on construction and gardening in higher and vocational colleges.Only thus can the roof greening of our country play its due role.%屋顶绿化能充分利用城市空间,增加城市的绿化面积,改善城市的生态环境,已成为城市园林绿化的重要组成部分。通过分析屋顶绿化的发展历史、植物选择、种植基质、建筑施工要素及植物的养护管理,发现在政策、技术和资金等许多方面都还存在一些问题,应在吸收发达国家屋顶绿化成功经验的基础上,根据国情和地方实际,制定和完善相应的法律法规,并从政府、开发商和户主三方筹集建设资金,还应加强屋顶绿化专门人才的培养,在高等和中职业院校涉及建筑、园林等方向的专业开设相关的专业课程,才能使我国的屋顶绿化起到应有的作用。

  19. 红外热像法研究屋顶绿化对热环境的影响%Study of Roof Greening's Effect on Thermal Environment by Using Infrared Thermography

    Institute of Scientific and Technical Information of China (English)

    郑星; 杨真静; 刘葆华; 郑晓楷; 范伟; 关庆庆

    2013-01-01

    该研究应用红外热像法测量绿化屋顶的表面温度,进而分析屋顶绿化对热环境的影响.通过采集斜坡屋顶绿化、轻型屋顶绿化和蓄水覆土屋顶绿化在阴天、雨后一天、晴天三种天气条件下的红外热像图,分析对比三种绿化屋顶在同一天内及三种不同天气条件下的温度变化.结果表明绿化屋顶表面温度的变化主要受太阳辐射和气温的影响,而蓄水覆土绿化屋顶的表面温度还受到其含水量的影响;屋顶绿化在夏季天气条件下可有效降低屋顶的表面温度、减小温度波动幅度,有利于改善城市热环境.%The aim of the present study is to detect the surface temperature of the green roofs by using infrared thermography,and then analyze the roof greening's effect on thermal environment.The slope roof greening,lightweight roof greening and water storage roof greening's infrared thermal images were shot in a cloudy day,a day after the rain and a sunny day,and then the same day and different days' surface temperatures of the three typical green roof were compared.The results show that the green roofs' surface temperature are mainly under the influence of solar radiation and air temperature,and water storage green roof's surface temperature is also influenced by its water content.Roof greening can effectively reduce the roof surface temperature and decrease the range of temperature fluctuation in any weather conditions.

  20. 浅析丽水市屋顶绿化的现状及适宜植物的选择%Analyzed Roof Greening Situation of Lishui City and the Selection of Suitable Plants

    Institute of Scientific and Technical Information of China (English)

    邹晓梅; 刘瑞瑜

    2013-01-01

      随着城市的发展,生态问题的凸现,因而诞生了一种新型的绿化形式——屋顶绿化。该文阐述了屋顶绿化的概念及分类,分析了丽水市屋顶绿化的现状;通过对丽水市的植物的调查研究,同时结合国内外屋顶绿化植物的选用及屋顶绿化植物配置的原则,筛选出适合丽水地区的屋顶绿化植物。%  this paper briefly introduces the concept and classification of urban roof greening,and analyzed the roof greening situation of Lishui city. Through to Lishui plant investigation and research,at the same time,com⁃bined with the selection of roof greening plants at home and abroad and the roof greening plant configuration, the principle of screening for Lishui Roof greening plants.

  1. 结合广州市实际谈城市屋顶绿化空间的综述%Review of Roof Greening Space in City with the Practice in Guangzhou City

    Institute of Scientific and Technical Information of China (English)

    刘惠连

    2014-01-01

    By col ecting, reading articles about city roof gree--ning space in recent years, the author introduced the concept, the development of roof greening, the main classification sys-tem and the key points of the technology, summarizing the fu-nction of roof greening. And combined with the practice, the author analyzed the existing problems of roof greening in Gu-angzhou city and final y proposed suggestions to promote the development of roof greening in city.%笔者通过收集、阅读近年来关于城市屋顶绿化空间的文章,介绍了屋顶绿化的概念、发展、主要分类系统和技术要点,概括了屋顶绿化的功能。并结合实际,分析了广州城市屋顶绿化的存在问题,最后提出了促进城市屋顶绿化发展的建议。

  2. 基于屋顶绿化热工性能研究节能降温效应%Energy Efficiency and Temperature Reduction Based on Green Roof

    Institute of Scientific and Technical Information of China (English)

    刘慧慧; 张高锋; 黄云; 曲胜; 谢闻文

    2016-01-01

    随着建筑能耗比例持续增高,屋顶绿化作为节能设计重点技术之一,具有巨大的节能潜力。通过屋顶绿化的构造及各层参数来分析屋顶绿化的隔热原理,并结合外表面温度、内表面温度和当量热阻3个影响因素阐释屋顶绿化对室内空调能耗的影响。以杭州市某住宅项目为研究对象,运用PHOENICS软件模拟整个住区环境的建筑实况,验证有无屋顶绿化时室内温度差值,来证明屋顶绿化确实减少室内空调运行能耗,一定程度上缓解周围热岛,为夏热冬冷地区隔热节能设计提供理论基础。%While the energy consumption of buildings has constantly increased, green roof, as one of the most important energy-saving methods, has huge potentiality. Through analyzing the heat insulation principles of green roof by studying its construction and parameters of each layer, its influence on the indoor HVAC energy consumption is studied by three factors: the external temperature, the internal temperature and the equivalent thermal resistance. Taking one of the residential projects in Hangzhou as an example, using PHOENICS software to simulate the thermal environment of the whole residential area, the indoor temperatures with and without the green roof construction are compared to prove the green roof method does decrease the indoor HVAC energy consumption and relieve the heat island effect, also provide the theoretical foundation to the research of energy-saving design in the hot summer and cold winter zone.

  3. 绿化屋顶雨水滞蓄能力试验研究%Experimental study on green roof stormwater retention

    Institute of Scientific and Technical Information of China (English)

    孙挺; 倪广恒; 唐莉华; 张书函; 孔刚

    2012-01-01

    屋顶绿化可以配合既有绿地涵养水分,是解决城市雨洪问题的有效策略之一。本文基于绿化屋顶观测试验结果,初步定量研究了北京城市气候下绿化屋顶的雨水滞蓄能力。结果表明:绿化屋顶具有较好的雨水持蓄能力,不同降雨条件下,约有70%的降雨被持蓄;绿化屋顶具有明显的减滞洪峰效果,不同降雨条件下,绿化屋顶均可有效的削减洪峰流量、延滞洪峰到达时间。根据降雨产流过程的观测与分析,归纳出绿化屋顶典型降雨产流模式,即可划分为初期雨水持蓄、快速产流及缓慢释放等3个阶段,并定量分析了各阶段的雨水持蓄特点。%Green roof is considered an efficient method for mitigating stormwater due to its water storage and retention capacity.An experiment was conducted to quantify the rainwater retention capacity of a green roof in Beijing.The observation during several natural and artificial rainfalls revealed a good relationship between retention capacity and rainfall amount.The green roof was able to retain roughly 70% of the rainfall and in all the events it resulted in a significant reduction in flood peak.The rainfall-runoff process of green roof can be divided into three stages,i.e.,first retention,rapid runoff,and retention restoration.

  4. PREDICTING THERMAL PERFORMANCE OF ROOFING SYSTEMS IN SURABAYA

    Directory of Open Access Journals (Sweden)

    MINTOROGO Danny Santoso

    2015-07-01

    Full Text Available Traditional roofing systems in the developing country likes Indonesia are still be dominated by the 30o, 45o, and more pitched angle roofs; the roofing cover materials are widely used to traditional clay roof tiles, then modern concrete roof tiles, and ceramic roof tiles. In the 90’s decay, shop houses are prosperous built with flat concrete roofs dominant. Green roofs and roof ponds are almost rarely built to meet the sustainable environmental issues. Some tested various roof systems in Surabaya were carried out to observe the roof thermal performances. Mathematical equation model from three references are also performed in order to compare with the real project tested. Calculated with equation (Kabre et al., the 30o pitched concrete-roof-tile, 30o clay-roof-tile, 45o pitched concrete-roof-tile are the worst thermal heat flux coming to room respectively. In contrast, the bare soil concrete roof and roof pond system are the least heat flux streamed onto room. Based on predicted calculation without insulation and cross-ventilation attic space, the roof pond and bare soil concrete roof (greenery roof are the appropriate roof systems for the Surabaya’s climate; meanwhile the most un-recommended roof is pitched 30o or 45o angle with concrete-roof tiles roofing systems.

  5. Adjustment Research of Green Roof and Solar Radiation for Severe Cold Area%严寒地区绿色屋顶对太阳辐射调节作用研究

    Institute of Scientific and Technical Information of China (English)

    陆明; 蔺阿琳

    2015-01-01

    China has abundant solar energy resources in severe cold regions, the green roofs can make ful use of solar radiation, based on the winter and summer climate characteristics, green roofs reduce energy consumption, increase the urban green area, improve the urban environment. Firstly, the paper presents benefits of green roofs, expounds the seasonal adjustment efects of green roof on solar radiation. Secondly, for the above purpose, analyses of the green roof design strategy for severe cold area of China. Finaly, develops prospect of green roofs in cold areas of China, which is low cost, inteligence and information.%我国严寒地区太阳能资源丰富,绿色屋顶可以充分利用太阳辐射,并结合严寒地区冬夏分明的气候特点,达到其减少能耗、增加城市绿地率、改善城市环境的目的.本文首先以绿色屋顶的性能优势为研究起点,阐述了严寒地区绿色屋顶对太阳辐射的季节性调节作用;其次,针对绿色屋顶对太阳辐射的季节性调节作用,分析了我国严寒地区绿色屋顶规划设计策略;最后,对我国严寒地区绿色屋顶的低成本、智能化和信息化的发展前景做出了展望.

  6. 屋顶栽培藤本蔬菜绿化降温试验%Greening and Temperature Cooling Test for Cultivating Lianoid Vegetables on Roof

    Institute of Scientific and Technical Information of China (English)

    解盼; 龙岳林

    2014-01-01

    Roof thermal radiation is an important reason causing urban thermal environment effect, and the roof greening is an effective way to reduce the thermal radiation. This study selects the balsam pear, lentils and towel gourd as test materials and adopts box-type cultivation method on the roof with steel mesh stent to respectively observe their growth adaptability and compare their temperature cooling effect for roof. The results showed that before middle July, the growth of sponge gourd and bitter melon was vigorous, but gradually declined with increasing temperature after middle July, but lentils had strong ability to resist high temperature, so it can maintain a strong growth state until met the frost; for greening and temperature cooling effect, before middle July, there was no significant difference among three kinds of vegetable, but lentils was obviously better than sponge gourd and bitter after middle July. Cultivating lianoid vegetables on roof has significant temperature cooling effect, the higher the temperature is, the temperature cooling effect the more obvious, especially at 12:00, the temperature cooling range was the largest by 8.7℃.%屋顶热辐射是导致城市热环境效应产生的一个重要原因,屋顶绿化是减轻热辐射的一项有效措施。选用苦瓜、扁豆和丝瓜作试验材料,在屋顶上采用箱式栽培方式,搭建钢丝网作支架,分别观测其生长适应性,并比较屋面降温效果。结果表明:7月中旬前丝瓜与苦瓜生长旺盛,7月中旬后随着温度升高而逐渐衰退,而扁豆具有较强的抗高温能力,一直保持旺盛生长状态,直到遇霜枯死;绿化降温效果7月中旬之前3种蔬菜无明显差异,7月中旬以后扁豆明显优于丝瓜和苦瓜。屋顶栽培藤本蔬菜降温效果显著,气温越高降温越明显,特别是在中午12:00降温幅度最大,达到8.7℃。

  7. 广州市不同类型屋顶绿化温湿度日变化初步研究%The Diurnal Variation Research of Temperature and Humidity of Different Types of Roof Greening in Guangzhou City

    Institute of Scientific and Technical Information of China (English)

    冼丽铧; 刘乾; 陈红跃; 沈志力; 杨水龙; 鲍海泳; 徐谙为; 覃艺伟

    2013-01-01

    为研究不同类型屋顶绿化的温湿度日变化,选择了广东省广州市越秀区地毯式、花园式和棚架式和盆花式4种不同的屋顶绿化类型,观测和统计分析不同绿化形式的屋顶及其不同空间位置的温度和湿度的变化.结果表明,各种类型的屋顶绿化对小气候都产生了显著的效应.其中,地毯式绿化类型植被覆盖度最高,降温效果最明显,温度最低;花园式和棚架式相当;盆花式效果较差,温度较高;各个测定位置的湿度数值则与温度相反,与降温效果一致.综合温湿度结果,4种屋顶绿化类型都产生了不同程度的生态效应,其中地毯式最佳,花园式和棚架式次之,盆花式较差.%For studying the diurnal variation of temperature and humidity of different types of roof greening, 4 types of green roofs including carpet, garden, frame and potted-flower in Yuexiu District of Guangzhou City were selected. The temperature and humidity changes in different types of green roofs with their locations were surveyed and analyzed. The results showed that various types of green roofs had a significant effect on the microclimate. A-mong the 4 types of green roofs, the carpet roof greening exhibited the best cooling effect with high vegetation cover. The garden and frame types were nearly the same exhibited better effect while the potted-flower type was the worst of all. The humidity measured at all types of roof garden were significantly higher than that of the exposed roof. Humidity effects were ranked as follows: carpet > garden and frame > potted-flower. In general, 4 types of roof greening had different degrees of ecological effect. Among them, carpet was the best. Garden and frame types were the secondary, while potted-flower was the poorest.

  8. Sustainable roofs with real energy savings

    Energy Technology Data Exchange (ETDEWEB)

    Christian, J.E.; Petrie, T.W.

    1996-12-31

    This paper addresses the general concept of sustainability and relates it to the building owner`s selection of a low-slope roof. It offers a list of performance features of sustainable roofs. Experiences and data relevant to these features for four unique roofs are then presented which include: self-drying systems, low total equivalent warming foam insulation, roof coatings and green roofs. The paper concludes with a list of sustainable roofing features worth considering for a low-slope roof investment. Building owners and community developers are showing more interest in investing in sustainability. The potential exists to design, construct, and maintain roofs that last twice as long and reduce the building space heating and cooling energy loads resulting from the roof by 50% (based on the current predominant design of a 10-year life and a single layer of 1 to 2 in. (2.5 to 5.1 cm) of insulation). The opportunity to provide better low-slope roofs and sell more roof maintenance service is escalating. The general trend of outsourcing services could lead to roofing companies` owning the roofs they install while the traditional building owner owns the rest of the building. Such a situation would have a very desirable potential to internalize the costs of poor roof maintenance practices and high roof waste disposal costs, and to offer a profit for installing roofs that are more sustainable. 14 refs., 12 figs.

  9. Sustainable roofs with real energy savings

    Energy Technology Data Exchange (ETDEWEB)

    Christian, J.E.; Petrie, T.W.

    1996-12-31

    This paper addresses the general concept of sustainability and relates it to the building owner`s selection of a low-slope roof. It offers a list of performance features of sustainable roofs. Experiences and data relevant to these features for four unique roofs are then presented which include: self-drying systems, low total equivalent warming foam insulation, roof coatings and green roofs. The paper concludes with a list of sustainable roofing features worth considering for a low-slope roof investment. Building owners and community developers are showing more interest in investing in sustainability. The potential exists to design, construct, and maintain roofs that last twice as long and reduce the building space heating and cooling energy loads resulting from the roof by 50% (based on the current predominant design of a 10-year life and a single layer of 1 to 2 in. (2.5 to 5.1 cm) of insulation). The opportunity to provide better low-slope roofs and sell more roof maintenance service is escalating. The general trend of outsourcing services could lead to roofing companies` owning the roofs they install while the traditional building owner owns the rest of the building. Such a situation would have a very desirable potential to internalize the costs of poor roof maintenance practices and high roof waste disposal costs, and to offer a profit for installing roofs that are more sustainable. 14 refs., 12 figs.

  10. Effects of leachate from crumb rubber and zinc in green roofs on the survival, growth, and resistance characteristics of Salmonella enterica subsp. enterica serovar Typhimurium.

    Science.gov (United States)

    Crampton, Mollee; Ryan, Allayna; Eckert, Cori; Baker, Katherine H; Herson, Diane S

    2014-05-01

    The use of green roofs is a growing practice worldwide, particularly in densely populated areas. In an attempt to find new methods for recycling crumb rubber, incorporation of crumb rubber into artificial medium for plant growth in green roofs and similar engineered environments has become an attractive option for the recycling of waste tires. Though this approach decreases waste in landfills, there are concerns about the leaching of zinc and other heavy metals, as well as nutrient and organic compounds, into the environment. The present study analyzed the impact of leachate from crumb rubber and zinc on the growth and viability of Salmonella enterica subsp. enterica serovar Typhimurium. Zinc was chosen for further studies since it has been previously implicated with other biological functions, including biofilm formation, motility, and possible cross-resistance to antimicrobial agents. The study showed that Salmonella can colonize crumb rubber and that crumb rubber extract may provide nutrients that are usable by this bacterium. Salmonella strains with reduced susceptibility (SRS) to zinc were obtained after subculturing in increasing concentrations of zinc. The SRS exhibited differences in gene expression of flux pump genes zntA and znuA compared to that of the parent when exposed to 20 mM added zinc. In biofilm formation studies, the SRS formed less biofilm but was more motile than the parental strain.

  11. The Influence of green areas and roof albedos on air temperatures during Extreme Heat Events in Berlin, Germany

    Directory of Open Access Journals (Sweden)

    Sebastian Schubert

    2013-04-01

    Full Text Available The mesoscale atmospheric model COSMO-CLM (CCLM with the Double Canyon Effect Parametrization Scheme (DCEP is applied to investigate possible adaption measures to extreme heat events (EHEs for the city of Berlin, Germany. The emphasis is on the effects of a modified urban vegetation cover and roof albedo on near-surface air temperatures. Five EHEs with a duration of 5 days or more are identified for the period 2000 to 2009. A reference simulation is carried out for each EHE with current vegetation cover, roof albedo and urban canopy parameters (UCPs, and is evaluated with temperature observations from weather stations in Berlin and its surroundings. The derivation of the UCPs from an impervious surface map and a 3-D building data set is detailed. Characteristics of the simulated urban heat island for each EHE are analysed in terms of these UCPs. In addition, six sensitivity runs are examined with a modified vegetation cover of each urban grid cell by -25%, 5% and 15%, with a roof albedo increased to 0.40 and 0.65, and with a combination of the largest vegetation cover and roof albedo, respectively. At the weather stations' grid cells, the results show a maximum of the average diurnal change in air temperature during each EHE of 0.82 K and -0.48 K for the -25% and 15% vegetation covers, -0.50 K for the roof albedos of 0.65, and -0.63 K for the combined vegetation and albedo case. The largest effects on the air temperature are detected during midday.

  12. The Application of Fine Soil Aggregate in Sloping Roof Greening——A Case Study on A Roof Greening in Shanghai%团粒喷播在斜面屋顶绿化上的应用——以上海某屋顶绿化工程为例

    Institute of Scientific and Technical Information of China (English)

    李春林; 吴刚; 宋益帆

    2011-01-01

    上海某斜面屋顶绿化项目总面积约15 000m,施工屋面共44块,坡度6°~44°.结合屋面的承重结构与设计风格,通过团粒喷播制备斜屋面绿化所需的土壤培养基,采用石笼结构建立屋面排水系统,配以自然式种植模式,呈现出整个屋面的草原风光.该案例的成功实施,填补了国内高陡斜面屋顶喷播绿化的空白,为我国斜面屋顶绿化技术的相关研究积累了宝贵经验.%A case of Shanhai's sloping roof greening project covers totally about 15 000 square meters, 44 pieces of roofing, and has slope of 6~44 degrees. Combining with the roof bearing structure and the style of design, the whole roof of grassland scenery have appeared and good results have been achieved by adopting the FSA vegetation restoration technology, using gabion structure on roof drainage system, and matching with natural type planting mode. The successful implementation of the case filled the blank of domestic steep sloping roof greening.And moreover, some valuable experience has been accumulated for the related research of sloping roof greening.

  13. 简单屋顶绿化的滞蓄特性%Rainwater retention features of extensive green roof

    Institute of Scientific and Technical Information of China (English)

    张华; 李茂; 张沣; 曹金露; 袁密

    2015-01-01

    An artificial rainfall device and a data acquisition system are designed to study the rainfall-runoff processes of an extensive green roof with matrix of 57.0% ceramsite,41.5% peat,and 1.5% super absorbent polymer.Based on 37 times artificial rainfall tests,the fundamental processes of rainfall infiltration and runoff are illustrated.The effects of rainfall intensity,matrix depth and initially water content on the rainwater retention features are studied.The results show that the effects of matrix depth and initially water content are significant.The rainwater storage in matrix will increase with lower initially water content and higher depth.A multiple linear regression equation is presented for the delayed time of runoff.It shows that the delayed time of runoff is negative related with rainfall intensity.Meanwhile the delayed time of runoff are affected by initial water content and depth.With the increase of wetting and drying times,the matrix depth tends to decrease,the rainwater storage gradually declines,and the delayed runoff time tends to shorten.%设计了模拟降雨与数据采集系统,研究了短时强降雨下简单屋顶绿化基质(配比:陶粒57.0%、草炭41.5%、保水剂1.5%)的降雨产流过程,基于37次模拟降雨实验,归纳了降雨产流的一般过程、规律和特性,分析了降雨强度、基质厚度和基质初始含水率对简单屋顶绿化滞流蓄水特性的影响。结果表明:基质厚度和基质初始含水率对简单屋顶绿化的蓄水特性有显著影响,基质初始含水率越低、基质厚度越厚时蓄水特性越佳。建立了产流时间数学模型,简单屋顶绿化降雨产流时间与降雨强度呈负相关,同时也受初始含水量和基质厚度影响。随着干湿循环次数增加,基质的厚度总体呈现下降趋势,储水性能逐渐下降,延迟产流时间逐渐缩短。

  14. Yellow-green luminescence and extreme thermal quenching in the Sr6M2Al4O15:Eu2+ (M = Y, Lu, Sc) phosphor series

    Science.gov (United States)

    Duke, Anna C.; Finley, Erin; Hermus, Martin; Brgoch, Jakoah

    2016-10-01

    A series of Eu2+-substituted yellow-green emitting phosphors based on the compound, Sr6M2Al4O15 (M = Y, Lu, Sc) were identified as potential efficient phosphors based on their high calculated Debye temperatures (ΘD > 450 K), which acts as a proxy for photoluminescent quantum yield (PLQY). The crystal structure contains corner-sharing [MO6] octahedra and [AlO4] tetrahedra leading to a highly connected, densely packed crystal structure. However, contrary to prediction, these compounds all showed a low PLQY (<6.5%) at room temperature. Temperature dependent luminescence measurements indicate that the photoluminescence is intense at 80 K but loses ≈90% of the emission intensity by room temperature, with the thermal quenching temperature (T50) occurring well below room temperature. These results suggest that even though Debye temperature (ΘD) is a valid proxy for PLQY, it does not describe thermal quenching.

  15. 100W class green 10ps 280µJ laser with M2<1.4 using Z-slab amplifier

    Science.gov (United States)

    Chard, Simon P.; Ramirez-Corral, Cristtel Y.; Bass, Michael; Chen, Ying; Kwon, Young K.

    2016-03-01

    A high-power green picosecond laser based on the `Z-slab' Nd:YAG amplifier is presented. The edge-pumped zigzag amplifier was designed to achieve high energy scaling with good beam quality. In a master oscillator power amplifier system 120 W average power was produced at 1064 nm, which was frequency doubled to 84 W at 532 nm. The maximum pulse energy was 400 μJ at 1064 nm and 280 μJ at 532 nm. The repetition rate was variable from 250 to 1000 kHz with M2 < 1.4. In burst mode with 1-10 pulses, over one millijoule total burst energy was demonstrated at 1064 nm.

  16. 哥本哈根屋顶绿化政策将推动城市向绿色城市转变%Copenhagen's Green Roofs Policy Will Boost the Transformation of the City to A Greener Living City

    Institute of Scientific and Technical Information of China (English)

    多拉茜·罗摩; 蒋巧璐; 邓巧

    2012-01-01

    Green roofs release the unused potential on roof tops to help people meet the challenge of climate changes and to meet the wishes for places to recreate in still more dense cities as well as for more roads,parking lots and buildings.Green roofs are a unique solution with many inherent benefits and can be regarded as one of the most sustainable and climate adapted solution for city development.Green roofs are going to be the key in the transformation of grey cities to green cities.To make this transformation happen we have to focus on the importance of making green roofs as a part of our policy for future city planning.%绿色屋顶项目通过释放屋顶空间的利用潜能,满足人们应对气候变化的挑战、在越加拥挤的城市中的公共场所进行休闲娱乐的需求,以及需要更加环保城市的同时,建造道路、停车场及其他类型建筑的需求。屋顶绿化是一种独特的解决途径,能够为人们带来众多益处,因此它也被认为是城市开发中最具有可持续发展、最能适应气候变化的手法之一。它是工业化城市向环保类型城市转变的关键。为推进这一进程,我们必须关注屋顶绿化的重要性,并将其纳入未来城市规划政策之中。

  17. 屋顶绿化在隔热降温·蓄水减排和净化屋面径流污染中的作用%The Effect of Green Roof in the Heat Insulation and Cooling, Rain Water Storage and Emission Reduction, Roofing Runoff Pollution Purification

    Institute of Scientific and Technical Information of China (English)

    许道坤; 吕伟娅; 张军

    2012-01-01

    Through the introduction of green roof, described the role of green roof: reducing the internal temperature and air conditioning energy consumption, etc. In summer, eliminating the urban heat island effect; through green roof's soil layer and drainage layer, storing rainwater, so that urban runoff can be modified, the pressure of rain pipes was relieved; combining the effects of plant and soil, cleaned the pollution of roof runoff and improved the utilization of water resources.%通过对屋顶绿化的介绍,描述了屋顶绿化的作用:夏季降低室内温度,减少空调等能耗,消除城市“热岛效应”;通过屋顶绿化中的土壤层与排水层,储存雨水,使城市雨水径流变得缓和,减轻雨水排水管压力;利用植物与土壤联合作用,去除屋面雨水径流中的污染物,提高雨水资源利用.

  18. Study on Comprehensive Evaluation System and Index Calculation of Light Roof-Greening in Urban Building%城市建筑轻型屋顶绿化综合评价体系及指标测算研究

    Institute of Scientific and Technical Information of China (English)

    谢丹凤; 郭树荣; 温丰源

    2016-01-01

    Light roof-greening is helpful in achieving energy-saving and emission reduction of the building itself. For three schemes naming roof greening,planting grass climbing greening and pergola greening,the paper designs comprehensive evaluation index system,and provides the appropriate method for calculating. At the same time,measures the indexes of thermal performance,energy-saving and consumption-reducing,cost,scope of application and landscape effects,and compares the comprehensive differences of the three schemes,provides reference for calculating and selecting schemes of light roof-greening.%轻型屋顶绿化有利于实现建筑物本身的节能减排。针对屋顶种植草绿化、爬藤绿化、棚架绿化三种方案,设计综合评价指标体系,给出相应的测算方法,并对热工性能、节能降耗、费用、适用范围、景观效果等指标进行测算,进而比较三种方案的综合差异,为轻型屋顶绿化指标测算及方案选择提供借鉴。

  19. Heat insulation structure of a green architecture roof and thermal performance property analysis%某绿色建筑屋顶隔热构造及热工性能分析

    Institute of Scientific and Technical Information of China (English)

    韩海涛; 杨晚生

    2009-01-01

    结合中对屋顶隔热节能的基本要求,对某公司综合楼的屋顶隔热构造模式进行了详细的分析和研究,并系统计算了不同构造模式的热工性能参数,提出了绿色建筑屋顶隔热的基本应用模式,以促进绿色建筑发展.%Combined with the basic requirements of roof heat insttlation and energy saving in "Green architecture eualuation standard", it makes a detailed analysis and research of the heat insulation structure pattern of the comprehensive building of a company and thermal perfor-mance property parameters of different structure pattems and puts forward the basic application pattern of green architecture roof heat insula-tion, so as to prromote the development of green architecture.

  20. Systems of Vegetal Façade and Green Roofs used as a Sustainable Option in Architecture

    OpenAIRE

    Chanampa, Mariana; Vidal Rivas, Pilar; Alonso Ojembarrena, Javier; Olivieri, Francesca

    2010-01-01

    Green architecture contributes not only in reducing the building’s thermal loads but also in reducing the effects of the urban heat island in densely built-up areas in a hardly natural environment. The current green systems are built in situ/on site and are very expensive, hence the need to create industrialized prevegetated systems which improve the buildings’ energy savings and reduce the times of construction works. The present paper describes three green systems for façades (gabion façade...

  1. Roof assembly

    CSIR Research Space (South Africa)

    De Villiers, A

    2010-01-01

    Full Text Available The objective of this chapter is to provide sustainability criteria for roof system design that can be used by planners, designers and developers as a planning, design and development guide for sustainable building projects....

  2. 绿化屋顶的产流规律及雨水滞蓄效果模拟研究%Study on Runoff and Rainwater Retention Capacity of Green Roof by Experiment and Model Simulation

    Institute of Scientific and Technical Information of China (English)

    唐莉华; 倪广恒; 刘茂峰; 孙挺

    2011-01-01

    As "the fifth facade" of city, the building roof is an important aspect for the cubist urban afforesting and greening. The rainwater retention and storage capacity of vegetation and soil layer on green roofs, to some extent, can reduce the urban stormwater runoff, delay the runoff generation, and improve the microclimate condition as well. In this study, an artificial raining experiment was carried out on green roof to analyze its rainwater storage capacity by measuring the rainfall and runoff. Then, a HYDRUS-1D model was established based on the greened roof structure. After model calibration and validation, it was used to simulate and analyze the influences of some key factors, including the rainfall, soil depth and soil characteristics. According to the experimental and calculated results, the green roof has good rainwater retention and storage capacity. For the green roofs with 10cm soil layer in this study, it varies from 16.1mm to 21.6mm according to different rainfall frequency. The capacity has an increase trend with the increase of soil depth. For the water storage effectiveness, loam is more suitable for roof greening than sandy soil and silt clay. These results can supply helpful information for the widespread implementation of green roofs in urban area.%建筑物屋顶作为城市的“第五面”,是城市立体化绿化的重要方面.通过屋顶绿化植被和土壤层的蓄滞作用,可在一定程度上延缓产流时间,减少城市径流,并改善局地微气候条件.开展了绿化屋顶的人工降雨径流观测实验,通过对降雨、径流的观测分析了绿化屋顶的雨水滞蓄效果.建立了描述绿化屋顶降雨产流过程的一维入渗模型HYDRUS-1D,利用实验数据进行了模型的率定和验证;并应用模型模拟分析了降雨频率、土层厚度和土壤类型等因素对绿化屋顶雨水滞蓄效果的影响.实验和模拟结果表明,绿化屋顶具有较好的雨水滞蓄效果,10cm土层厚度的绿化

  3. Measured Energy Savings from the Application of Reflective Roofs in 3 AT and T Regeneration Buildings

    Energy Technology Data Exchange (ETDEWEB)

    Akbari, Hashen; Rainer, Leo

    2000-11-01

    Energy use and environmental parameters were monitored in three AT and T regeneration buildings during the summer of 2000. These buildings are constructed with concrete and are about 14.9 m2 (160 f2; 10x16 ft)in size. The buildings were initially monitored for about 1 1/2 months to establish a base condition. Then, the roofs of the buildings were painted with a white coating and the monitoring was continued. The original roof reflectances were about 26 percent; after the application of roof coatings the reflectivities increased to about 72 percent. In two of these buildings, we monitored savings of about 0.5kWh per day (8.6 kWh/m2 [0.8 kWh/ft2]). The third building showed a reduction in air-conditioning energy use of about 13kWh per day. These savings probably resulted from the differences in the performance (EER) of the two dissimilar AC units in this building. The estimated annual savings for two of the buildings are about 125kWh per year; at a cost of dollar 0.1/kWh, savings are about dollar 12.5 per year. Obviously, it costs significantly more than this amount to coat the roofs with reflective coating, particularly because of the remote location of the buildings. However, since the prefabricated roofs are already painted green at the factory, painting them with white (reflective) color would bring no additional cost. Hence the payback time for having reflective roofs is nil, and the reflective roofs save an accumulated 370kWh over 30 years of the life of the roof.

  4. Green roofs as contributors for water management schemes within urban areas – a pilot study in Porto

    OpenAIRE

    Monteiro,C.M.; Calheiros, C. S. C.; Pimentel-Rodrigues, C.; Palha,P.; Silva-Afonso, A.; Castro, P. M. L.

    2016-01-01

    Water scarcity is an issue of worldwide concern and a holistic approach to water management is needed to overcome the potential threats that climate change brings to water availability and security in many parts of the globe. Societal and economic challenges need to be addressed when implementing technological solutions to environmental problems. The fact that green areas in the cities have been reduced and replaced by impervious buildings and paved streets has caused a number of problems, su...

  5. Climate Adaptive Planning for Urban green Roof System Chengdu Case Study%基于气候适应性的城市屋顶绿化系统规划研究以成都为例

    Institute of Scientific and Technical Information of China (English)

    董靓; 黄瑞

    2014-01-01

    城市屋顶绿地应是以本地地域气候特征为基本出发点和落脚点。以适应气候为评价标准的屋顶绿地系统规划则应在规划布局上疏导城市通风;并利用热岛环流造风;利用屋顶绿化分散污染高浓度区域。以成都为例,从改善城市风环境的角度,探讨城市尺度的屋顶绿化系统的气候适应性规划问题。%Urban roof green space should make local regional climate features as its starting point and foundation. And the climate-adaptive roof green space planning should be beneficial to city ventilation, local air circulation and dividing high pol uted areas into smal er areas. Taking Chengdu as case study, this paper discusses climate adaptive planning for city-scale urban green roof system for the purpose of improving urban wind environment.

  6. Practice And Discussion Which Is Based On The Integrated Design Of Green Roof Types%基于屋顶绿化类型的一体化设计探讨与实践

    Institute of Scientific and Technical Information of China (English)

    向俊米; 刘宏成; 肖敏; 刘健璇

    2016-01-01

    Green roofs can effectively improve the indoor environment and forming certain ecological effect, but also exist some construction and maintenance problem. According to the characteristics of the original architecture, based on"low price and high eficiency" principle, it connects diferent types of roof greening to the coresponding integrated design, and puts into practice and achieved good efect with good reference value to the design of roof greening.%屋顶绿化能有效改善室内环境,形成一定的生态效应,同时也存在着施工与维护困难等相应的问题。以原有建筑为依据结合“低价高效”的原则,对不同类型的屋顶绿化进行一体化设计的相应探讨,并付诸实践,取得了良好的效果,对屋顶绿化设计有较好的参考价值。

  7. Discussion on the Effect of Policies and Regulations on Improving Popularizing Rate of Roof Greening%政策法规对提高屋顶绿化普及率所起作用的探讨

    Institute of Scientific and Technical Information of China (English)

    王雨竹

    2011-01-01

    以日本、德国、美国为参照,介绍了国外屋顶绿化先进国家的相关政策法规,结合中国的具体实际,解析了上海、杭州、西安等城市在促进屋顶绿化方面的具体政策法规内容.提出了在提高屋顶绿化普及率方面,政府政策法规的扶持将会起到关键性作用的观点.%With Japan, Germany and America as the reference, the related policies and regulations about roof greening in advanced countries were introduced, and combining with the reality of China, the specific policies and regulations about roof greening in Shanghai, Hangzhou and Xi' an, etc. were analyzed. To improve the popularizing rate of roof greening, the support of government' s policies and regulations will play the important role.

  8. Review of green roof in controlling unban non-point source pollution%绿色屋顶技术控制城市面源污染应用研究进展

    Institute of Scientific and Technical Information of China (English)

    王书敏; 于慧; 张彬; 邵磊

    2011-01-01

    It has been widely adopted abroad that green roof is an effective mode in controlling Urban Non-point Source Pollution(UNSP),which still belongs to new research fields in China.Based on studies in recent years home and abroad,highlight is given about green roof in controlling unban non-point source pollution from three aspects(i.e.,the reduction and retention of runoff volume,water quality from green roof and the installation method of green roof).Results show that further study is needed for a long time in order to establish the function between stormwater runoff reduction volume and influencing factors;the physical and chemical properties of plants growth media is the key problem affecting runoff water quality.It should follow a wide rang of purposes to install green roofs at home,and the design guidance for green roofs should also be made according to domestic environmental background.The plants growth substrate and the choice of plants are primary problems to be ascertained.%应用绿色屋顶技术控制城市面源污染在欧美国家已得到广泛认同和应用,但在国内尚处于起步阶段.根据国内外最近几年的研究情况,从绿色屋顶消减暴雨径流、绿色屋顶径流水质、绿色屋顶构建方法等方面详细介绍了绿色屋顶技术在控制城市面源污染中的应用研究情况.研究结果表明,建立绿色屋顶暴雨径流消减量与影响因子的映射关系仍需要大量的、长期的研究;植物生长介质的理化性质是影响绿色屋顶径流水质的关键.在国内构建绿色屋顶,应遵循构建目的多元化的原则,逐步建立起适合国内国情的新的绿色屋顶构建导则,其中,植物生长基质搭配方式和植物选取是需要重点明确的问题.

  9. Mitigating the cooling need and improvement of indoor conditions in Mediterranean educational buildings, by means of green roofs. Results of a case study

    Science.gov (United States)

    Ascione, F.; Bianco, N.; De Masi, R. F.; de Rossi, F.; Vanoli, G. P.

    2015-11-01

    Indoor overheating risk and increased energy demand for cooling are becoming more and more frequent in the building sector of the Mediterranean area. In detail, for the reduction of the energy consumption of educational buildings, characterized by high endogenous gains, the particular boundary conditions affecting their use should be taken in consideration, and thus schedules of occupancy, wide necessity of air-changes for air quality. This paper, with reference to a case study, proposes deep investigations aimed at optimizing the annual energy performance of an educational building of the University of Sannio, located in the Southern Italy. A numerical model of the building has been designed and validated according to monitored data. Starting from the present scenario, after a complete refurbishment of the building envelope, the potentialities of several typologies of green roofs - by considering also the implementation of the adaptive approach in the comfort standard - have been tested. The scope is the optimization of the energy demand for the annual microclimatic control, by avoiding an energy-intensive operation of the air-conditioning devices during the warm season.

  10. Study on Artificial Matrix of Saving Light Roof Greening%轻型屋顶绿化人工基质配方的筛选

    Institute of Scientific and Technical Information of China (English)

    张杰; 李海英; 侯晓红

    2011-01-01

    Peatmoss and construction waste materials were selected as the raw material, 6 treatments were set up, and rural soil was taken as a comparison. According to the tests on the basic physical and chemical properties of substrate,growth index and the rate of water loss, and combing tests of permanent wilting plants, it was found that 90% grassland substrate carbon: 10% broken roof tiles on the combination was more suitable as a light green Sedum plants substrate compositions.%选取草炭土和建筑废料作为基质原料,设置了6个处理,同时选取田园土作为对照,通过对不同配方基质理化性质、基质失水率、植物生长量的测定,结合永久性萎蔫试验,对轻型屋顶绿化基质进行了研究.结果表明,90%草碳土:10%碎砖块的配方适合作为轻型屋顶绿化景天属植物的基质配比.

  11. Potential benefits of plant diversity on vegetated roofs: a literature review.

    Science.gov (United States)

    Cook-Patton, Susan C; Bauerle, Taryn L

    2012-09-15

    Although vegetated green roofs can be difficult to establish and maintain, they are an increasingly popular method for mitigating the negative environmental impacts of urbanization. Most green roof development has focused on maximizing green roof performance by planting one or a few drought-tolerant species. We present an alternative approach, which recognizes green roofs as dynamic ecosystems and employs a diversity of species. We draw links between the ecological and green roof literature to generate testable predictions about how increasing plant diversity could improve short- and long-term green roof functioning. Although we found few papers that experimentally manipulated diversity on green roofs, those that did revealed ecological dynamics similar to those in more natural systems. However, there are many unresolved issues. To improve overall green roof performance, we should (1) elucidate the links among plant diversity, structural complexity, and green roof performance, (2) describe feedback mechanisms between plant and animal diversity on green roofs, (3) identify species with complementary traits, and (4) determine whether diverse green roof communities are more resilient to disturbance and environmental change than less diverse green roofs.

  12. 基于生命周期评价的生态绿屋面形式比较测试研究%Compare and test different forms of green-roofs with LCA theory

    Institute of Scientific and Technical Information of China (English)

    李恒威; 叶建军; 魏道江

    2012-01-01

    为了评定生态绿屋面的环境效益,提出生态绿屋面的形式分类比较方法,针对绿屋面生产、施工阶段全寿命周期评价(LCA)比较分析,尤其是栽培条件、规模形态以及经济效益等方面的测试与评价.同时采用热流计对建筑屋面的传热系数进行了现场实测与测量误差分析,得到比较结论.计算模型和实测数据结果对不同形式生态绿屋面设计应用选择有一定的参考价值.%In order to evaluate the environmental benefit of ecological roofs, the authors proposed the method to classify the types of green roofs. Based on the LCA(life cycle assessment) theory, the method compared green roofs in construction and delivering stages, which especially tested and evaluated cultivation conditions, sizes, economic effectiveness, etc. Meanwhile the heat transfer coefficients were measured with heat flux meter in site and the errors are analyzed, orderly the conclusion was drawn by comparing those parameters. The computing model and the measured data are very useful for the designer to make right choice from the different forms of green roofs.

  13. Hydrological Response of Sedum-Moss Roof

    Science.gov (United States)

    Bengtsson, L.

    2004-12-01

    Eco-roofs are becoming popular for aesthetic reasons and also as units of stormwater systems. It is thought that such roofs with soil cover and vegetation reduces the total runoff, the peak flows and improves the quality of the roof water. Here are reported investigations of runoff from thin, 3-4 cm soil, extensive green roofs with sedum-moss in southern Sweden. The two-year study was performed on new roofs in the eco-city Augustenborg and also on nearby old vegetative roofs. The rain intensity and the roof runoff were measured with 5 min, or in some experiments with 1 min, resolution. The annual runoff from the eco-roofs was about half that from hard roofs and was close to that of small natural rivers. However, although most rainy days there was no or little runoff from the roofs, the highest observed daily runoff values were close to the daily rainfall. Runoff is initiated, when the soil is at field capacity. Thereafter the hourly runoff corresponds closely to the hourly rainfall. For short-term high intensity storms, the runoff peak is attenuated relative the rain intensity. The time of concentration for runoff was experimentally determined applying artificial rains on existing roofs and on experimental roof plots with varying slopes and using different drainage layers. The peak runoff from the roofs was found to correspond to the rain intensity over 20-30 minutes. The probability of high rain intensity is much higher than the probability of high runoff. When intensity-duration-frequency curves were constructed, runoff with 0.4 year return period corresponded to rain with 1.5 year return period. The influence of the slope of the roofs on the runoff peak was minor as was the effect of drainage layer. The vertical flow in the soil dominates the runoff process. The influence of extensive sedum-moss vegetated roofs on runoff quality was also studied to ascertain whether vegetated roofs behave as sink or source of pollutants and whether the runoff quality changes

  14. 太阳能自动灌溉技术在屋面绿化工程中的应用%Application of automatic solar energy irrigation technology in roof greening engineering

    Institute of Scientific and Technical Information of China (English)

    苏建华; 汤聪; 吴毅; 李慧莹

    2014-01-01

    On the basis of existing automatic solar energy irrigation technology and automatic spraying technology,the paper solves roof park cul-tivation enclosure problems by adding roof greening retaining board,improves some measures,and solves planting enclosure leakage and erosion problems owing to ponding,and sets automatic solar energy irrigation control instrument and automatic rotary water-saving sprinkler. As a result, it realizes automatic roof greening irrigation and achieves good economic and social benefits.%在已有的太阳能自动灌溉技术和自动喷淋技术的基础上,通过增设屋顶绿化种植挡板解决了屋顶花园栽培基质的围护问题,同时改进措施,解决了种植围护结构因积水造成的漏水和腐蚀问题,并通过设置太阳能全自动灌溉控制器和自动旋转节水喷头,实现了屋面绿化的自动灌溉,从而取得了良好的社会、经济效益。

  15. Roof Greening Resistance Research and Analysis in Guiyang City%城市小区屋顶绿化抗逆性研究与分析

    Institute of Scientific and Technical Information of China (English)

    江钟

    2016-01-01

    通过贵阳小区屋顶绿化实验设计,对13种贵阳常见的屋顶绿化植物进行干旱和水淹的胁迫实验,对植物在不同胁迫下的生长状况进行了记录,同时测定了土壤含水量和叶绿素含量等指标的数据,并利用excel和spss软件对实验数据进行分析。实验结果表明,这13种植物的抗旱性的强弱顺序为:佛甲草>盆垂草>景天>紫藤>尖叶石竹>月季>合欢>黄馨>蔷薇>木香>红叶李>紫薇>菊花;耐涝性的强弱顺序为:盆垂草>佛甲草>紫藤>景天>尖叶石竹>紫薇>合欢>红叶李>黄馨>蔷薇>木香>月季>菊花。从实验结果可知,这13种植物的抗逆性存在较大的差异,其中佛甲草、盆垂草、景天的抗逆性最强;而菊花的抗逆性最弱。%By Guiyang area roof greening design of experiment, the 13 kinds of the common roof greening plants in Guiyang drought and flooding experiment, the stress on the growth of plants under different stress conditions for the record, at the same time measured the indexes of soil water content and chlorophyll content of data, and use the excel and SPSS software to analyze the experimental data. Experimental results show that the 13 kinds of plant drought resistance of the strength of the order:Buddha a grass>basin vertical grass>>view day wisteria>leaves China pink rose>>meadow>shin wong>>Rosa combination>gongxieli ziwei>>chrysanthemum;Basin of waterlogging resistance of the pecking order is: the vertical grass > fo a grass > wisteria > > view days leaves carnation ziwei > >meadow > gongxieli > shin wong > > Rosa combination > chrysanthemum > Chinese rose. From the experiment result shows that there are many differences between the 13 kinds of plant resistance, the Buddha a grass, grass, basin the strongest days of the resistance;And the resistance of chrysanthemum is the most weak.

  16. Understanding Roofing Systems.

    Science.gov (United States)

    Michelsen, Ted

    2001-01-01

    Reviews the various types of multi- and single-ply roofing commonly used today in educational facilities. Roofing types described involve built-up systems, modified bitumen systems; ethylene propylene diene terpolymer roofs; and roofs of thermoplastic, metal, and foam. A description of the Roofing Industry Educational Institute is included. (GR)

  17. COMPARATIVE STUDY OF DIFFERENT TYPES OF ROOF AND INDOOR TEMPERATURES IN TROPICAL CLIMATE

    Directory of Open Access Journals (Sweden)

    Mrs. M. Ponni

    2015-04-01

    Full Text Available A roof provides protection to be safe from direct sunlight. From the shelter, shadow alone is not expected. Durability, sustainability, less life cycle cost, and low maintenance cost are expected from a selected roof. The world has a thirst to have a best roof. No roof will fulfil the requirement of humanity since the climatic conditions are different. Hence the roof should be selected according to the prevailing climate. And the roof selection depends on the need, taste and the spending capability of the house owner. Thatched shed, tiles covered roof, light roofs either using galvanized sheets or asbestos sheets, painted or unpainted metal sheets, RCC, Green roof, Roof pond, insulated roof, reflective roof, and cool roof are the roofs so far brought into use. Whatever be the roof, it should provide thermal comfort. Thermal comfort is felt through the thermal experience of the occupants. Thermal experience depends on the indoor temperature. Energy efficiency of a building is highly based on the indoor ambient temperature. Energy efficiency in buildings is compelling, cost effective, saves money and useful to compromise resource energy shortage. A light roof named as Single Decker (SID and an insulated double roof using hybrid technique named as (DOD are taken for this study. Among the selected roofs the DOD provides a better thermal performance and thermal comfort. The study has been carried out for the summer peak period in April 2014. Thermal performance and indoor temperature of the DOD is compared with other roof studies.

  18. Detection and identification of Nosema ceranae by dual fluorescent staining with Calcofluor White M2R and Sytox Green%Calcofluor White M2R与Sytox Green双重染色法鉴别蜜蜂微孢子虫

    Institute of Scientific and Technical Information of China (English)

    秦浩然; 李继莲; 和绍禹; 吴杰

    2012-01-01

    东方蜜蜂微孢子虫( Nosema ceranae)是一种广泛寄生于东方蜜蜂Apis cerana,西方蜜蜂Apis mellifera和熊蜂Bombus Latreille上的寄生虫,对蜜蜂和熊蜂的危害较大,进而影响养蜂业的发展.本实验采用荧光染色试剂Calcofluor White M2R与核酸染料Sytox Green双重染法来鉴别蜜蜂或熊蜂体内的N.ceranae及孢子的存活状态.结果得出,在荧光显微镜下可见死孢子被染上黄绿色荧光,活的呈现蓝白色荧光,而寄主细胞、细菌、病毒等不被染色.这是一种快速有效鉴别N.ceranae及其死活的方法,从而判定蜜蜂或熊蜂体内的微孢子虫在是否具有侵染活性,对微孢子虫的研究及药物防治具有重要作用.%Nosema ceranae is a microsporidian parasite of Apis cerana, Apis mellifera and bumblebees that has an adverse effect on pollination, especially of fruits and vegetables, and apiculture. In this study, Calcofluor White M2R and Sytox Green stains were used to discriminate between live and dead N. ceranae. The results show that dead N. ceranae spores had yellow-green fluorescence whereas live spores fluoresced white - blue. This method allows easy detection and identification of live and dead N, ceranae and should therefore contribute to further research on TV. ceranae and its treatment.

  19. Water retention capacity of typical roof greening matrices%常用屋顶绿化基质材料的保水性能

    Institute of Scientific and Technical Information of China (English)

    张华; 李茂; 曹金露; 张沣

    2015-01-01

    研究在饱和状态、反复干湿循环和自然蒸发3种情况下常用屋顶绿化基质材料陶粒、草炭和保水剂的保水性能。通过抽真空饱和试验得到基质材料的蓄水性能,试验发现基质材料混合后实测饱和含水量大于理论推算值,分析了导致材料混合使得蓄水性能大幅提高的原因。采用反复干燥吸水试验证明陶粒和草炭具有良好的热稳定性,而保水剂在较高温度烘干时主分子链易断裂,反复吸水和烘干后其保水性能大幅降低。常温常压蒸发试验表明在含水量较高时,三者蒸发速率与自由水面蒸发的相当,随着含水量降低,保水性能越差的基质材料蒸发速率降低越快,合理添加保水剂能有效改善基质材料保水性能。%The water retention capacities of commonly used roof greening matrices ,concluding ceramsite ,peat and super absorbent polymer ,under fully saturated ,cyclic wetting‐drying and natural evaporation conditions were studied .The saturated water retention capacity of matrices were obtained by vacuum saturated test .It showed that the fully measured saturated degree of saturation of mixed matrix was greater than that calculated by the combination of all components .The reason which increases the water contents to porous skeleton was analysed .In cyclic wetting‐drying tests ,the water retention capacities of ceramsite and peat were almost unchanged .However , due to the main molecular chain broken under drying in relatively high temperature ,the water retention capacity decreased rapidly after several wetting‐drying cycles . In natural evaporation tests , the evaporation rates of ceramsite ,peat , super absorbent polymer and free water were almost identical in the condition of high water content .As the water content decreasing ,the evaporation rate of the matrix which had lower water retention capacities decreases faster .The matrix with a reasonable proportion of super

  20. Valuation of Green Walls and Green Roofs as Soundscape Measures: Including Monetised Amenity Values Together with Noise-attenuation Values in a Cost-benefit Analysis of a Green Wall Affecting Courtyards

    Directory of Open Access Journals (Sweden)

    Jian Kang

    2012-10-01

    Full Text Available Economic unit values of soundscape/acoustic effects have been based on changes in the number of annoyed persons or on decibel changes. The normal procedure has been the application of these unit values to noise-attenuation measures affecting the noisier façade of a dwelling. Novel modular vegetation-based soundscape measures, so-called green walls, might be relevant for both noisy and quieter areas. Moreover, their benefits will comprise noise attenuation as well as non-acoustic amenity effects. One challenge is to integrate the results of some decades of non-acoustic research on the amenity value of urban greenery into design of the urban sound environment, and incorporate these non-acoustic properties in the overall economic assessment of noise control and overall sound environment improvement measures. Monetised unit values for green walls have been included in two alternative cases, or demonstration projects, of covering the entrances to blocks of flats with a green wall. Since these measures improve the noise environment on the quiet side of the dwellings and courtyards, not the most exposed façade, adjustment factors to the nominal quiet side decibel reductions to arrive at an estimate of the equivalent overall acoustic improvement have been applied. A cost-benefit analysis of the green wall case indicates that this measure is economically promising, when valuing the noise attenuation in the quieter area and adding the amenity/aesthetic value of the green wall.

  1. Valuation of green walls and green roofs as soundscape measures: including monetised amenity values together with noise-attenuation values in a cost-benefit analysis of a green wall affecting courtyards.

    Science.gov (United States)

    Veisten, Knut; Smyrnova, Yuliya; Klæboe, Ronny; Hornikx, Maarten; Mosslemi, Marjan; Kang, Jian

    2012-10-24

    Economic unit values of soundscape/acoustic effects have been based on changes in the number of annoyed persons or on decibel changes. The normal procedure has been the application of these unit values to noise-attenuation measures affecting the noisier façade of a dwelling. Novel modular vegetation-based soundscape measures, so-called green walls, might be relevant for both noisy and quieter areas. Moreover, their benefits will comprise noise attenuation as well as non-acoustic amenity effects. One challenge is to integrate the results of some decades of non-acoustic research on the amenity value of urban greenery into design of the urban sound environment, and incorporate these non-acoustic properties in the overall economic assessment of noise control and overall sound environment improvement measures. Monetised unit values for green walls have been included in two alternative cases, or demonstration projects, of covering the entrances to blocks of flats with a green wall. Since these measures improve the noise environment on the quiet side of the dwellings and courtyards, not the most exposed façade, adjustment factors to the nominal quiet side decibel reductions to arrive at an estimate of the equivalent overall acoustic improvement have been applied. A cost-benefit analysis of the green wall case indicates that this measure is economically promising, when valuing the noise attenuation in the quieter area and adding the amenity/aesthetic value of the green wall.

  2. Green Infrastructure Modeling Toolkit

    Science.gov (United States)

    Green infrastructure, such as rain gardens, green roofs, porous pavement, cisterns, and constructed wetlands, is becoming an increasingly attractive way to recharge aquifers and reduce the amount of stormwater runoff that flows into wastewater treatment plants or into waterbodies...

  3. The Roof Garden Green Building Development Idea Research in Jilin Area%吉林地区屋顶花园式绿色建筑发展构想研究

    Institute of Scientific and Technical Information of China (English)

    刘国敏; 陶瑞峰

    2012-01-01

    通过对现代绿色建筑设计与运用、创新及发展的构想,以及吉林地区发展屋顶花园的构成要素、构景要素、生态绿化的立体延伸、存在的问题与解决方法的分析,为屋顶花园式绿化建筑在吉林地区的推广提供完善的理论依据和技术支持.%The design and application, innovation and development conception of modern green building, and the elements of constitution and the composition of the scenery, ecological afforestation landscape of three-dimensional extensions, the existing problems and solutions of the roof garden in Jilin area were analyzed, which will provide perfect theory basis and technique support of roof garden afforestation in Jilin area.

  4. New roof element system

    DEFF Research Database (Denmark)

    Ditlev, Jesper; Rudbeck, Claus Christian

    1997-01-01

    The aim of the project has been to develop an element system for warm deck roofs which, from a thermal and economical point of view, can deal with the future demands for heat loss coefficients for low slope roofs.......The aim of the project has been to develop an element system for warm deck roofs which, from a thermal and economical point of view, can deal with the future demands for heat loss coefficients for low slope roofs....

  5. Renovation of Roof Structure

    DEFF Research Database (Denmark)

    Kjærbye, Per Oluf H

    1997-01-01

    A 30 year old not-watertight roof based on wooden boards with roofing felt have been changed to a pitched structure with cementos plates. At the same time more thermal insulation has been placed.......A 30 year old not-watertight roof based on wooden boards with roofing felt have been changed to a pitched structure with cementos plates. At the same time more thermal insulation has been placed....

  6. New roof element system

    DEFF Research Database (Denmark)

    Ditlev, Jesper; Rudbeck, Claus Christian

    1997-01-01

    The aim of the project has been to develop an element system for warm deck roofs which, from a thermal and economical point of view, can deal with the future demands for heat loss coefficients for low slope roofs.......The aim of the project has been to develop an element system for warm deck roofs which, from a thermal and economical point of view, can deal with the future demands for heat loss coefficients for low slope roofs....

  7. Modelling reduction of urban heat load in Vienna by modifying surface properties of roofs

    Science.gov (United States)

    Žuvela-Aloise, Maja; Andre, Konrad; Schwaiger, Hannes; Bird, David Neil; Gallaun, Heinz

    2017-01-01

    The study examines the potential of urban roofs to reduce the urban heat island (UHI) effect by changing their reflectivity and implementing vegetation (green roofs) using the example of the City of Vienna. The urban modelling simulations are performed based on high-resolution orography and land use data, climatological observations, surface albedo values from satellite imagery and registry of the green roof potential in Vienna. The modelling results show that a moderate increase in reflectivity of roofs (up to 0.45) reduces the mean summer temperatures in the densely built-up environment by approximately 0.25 °C. Applying high reflectivity materials (roof albedo up to 0.7) leads to average cooling in densely built-up area of approximately 0.5 °C. The green roofs yield a heat load reduction in similar order of magnitude as the high reflectivity materials. However, only 45 % of roof area in Vienna is suitable for greening and the green roof potential mostly applies to industrial areas in city outskirts and is therefore not sufficient for substantial reduction of the UHI effect, particularly in the city centre which has the highest heat load. The strongest cooling effect can be achieved by combining the green roofs with high reflectivity materials. In this case, using 50 or 100 % of the green roof potential and applying high reflectivity materials on the remaining surfaces have a similar cooling effect.

  8. The M2 Channel

    DEFF Research Database (Denmark)

    Santner, Paul

    and inhibition mechanisms, drug design studies were recently able to achieve successes in finding new potent inhibitors, some of which are even able to inhibit resistant M2 variants. Effective and robust methods for measuring M2 activity on the other hand are still scarce and tactics to assess the genetic...... barrier of new inhibitors as well as resistance development non-existent. Therefore we developed a fluorescence sensor based assay that directly measures proton conduction (pHlux assay) and combined it with an already established directed evolution selection and screening system of M2 to identify possible...... resistance escape routes from drug inhibition. We thereby were hopefully able to provide a platform for the large-scale evaluation of M2 channel activity, inhibitors and resistance....

  9. Influence of the Substrate Composition in Extensive Green Roof on the Effluent Quality%粗放型绿色屋面填料的介质组成对出水水质的影响

    Institute of Scientific and Technical Information of China (English)

    陈昱霖; 李田; 顾俊青

    2014-01-01

    通过模拟降雨实验监测填料组成不同的绿色屋面模拟设施出水水质,研究粗放型绿色屋面设施填料组成对出水污染物特征的影响.结果表明,设施出水中主要的污染物包括不同形态的 N、P 以及 COD;除 COD 外,出水中污染物浓度随累积降雨量增加而下降,具有明显的淋失效应;所有设施出水中重金属含量均较低,初期出水的平均浓度均达到饮用水标准.含有田园土、醋糟的绿化种植土出水营养物质淋失严重,在累计降雨150 mm 情况下,设施出水 TN、TP、COD 平均浓度分别为2.93、0.73和78 mg·L -1,均超过地表水水质标准V类的限值,添加水厂污泥可以有效地减少绿化种植土中 TP 的淋出且不影响植物对 P 的吸收;使用无机复合种植土的设施出水水质较好,但仍需要结合设施对水量削减能力和植物生长状况判断填料是否能够应用于粗放型绿色屋面.%By monitoring the effluent quality from different green roof assemblies during several artificial rain events, the main pollutant characteristics and the influence of substrate composition in extensive green roof on the effluent quality were studied. Results showed that the main pollutants in the effluent were N, P and COD; with the increase of cumulative rain, the concentrations of pollutants in the effluent decreased, which had obvious leaching effect; The average concentrations of heavy metals in the early effluent from all assemblies reached drinking water standard, including the assemblies using crushed bricks; When garden soil and compost were used as organic matter, the assemblies had serious leaching of nutrient substance. After the accumulated rainfall reached 150 mm, the TN, TP and COD concentrations of effluent were 2. 93, 0. 73 and 78 mg·L - 1 , respectively, which exceeded the Surface water V class limit. By means of application of the Water Treatment Residual, the leaching of TP from green planting soil was

  10. 种植屋面构造探讨及实践%Discussion of green roofing composition and its application

    Institute of Scientific and Technical Information of China (English)

    王清江; 王悦

    2016-01-01

    The paper introduces the role of the architectural plantation roof and its classification,analyzes some problems in the projects of China, and explores its measures for its components,so as to achieve better energy-saving,social and economic benefits by adopting the methods in the projects.%介绍了建筑种植屋面的作用及分类,分析了现阶段我国屋面种植工程存在的问题,探讨了种植屋面的构造作法,并将该作法应用在具体工程中,取得了较好的节能效果和社会经济效益.

  11. IMPROVED ROOF STABILIZATION TECHNOLOGIES

    Energy Technology Data Exchange (ETDEWEB)

    M.A. Ebadian, Ph.D.

    1999-01-01

    Many U.S. Department of Energy (DOE) remediation sites have performed roof repair and roof replacement to stabilize facilities prior to performing deactivation and decommissioning (D&D) activities. This project will review the decision criteria used by these DOE sites, along with the type of repair system used for each different roof type. Based on this information, along with that compiled from roofing experts, a decision-making tool will be generated to aid in selecting the proper roof repair systems. Where appropriate, innovative technologies will be reviewed and applied to the decision-making tool to determine their applicability. Based on the results, applied research and development will be conducted to develop a method to repair these existing roofing systems, while providing protection for the D and D worker in a cost-efficient manner.

  12. Comparison of different UHI mitigation strategies: the street- versus roof-level implementation

    Science.gov (United States)

    Li, X.; Georgescu, M.; Norford, L. K.

    2015-12-01

    Many mitigation approaches have been proposed to ameliorate the deleterious aspects of urbalization on climate, with special focus on the notorious urban heat island (UHI) effect. Of these approaches, high reflectance roof (cool roof) and pavement (cool pavement) and green roof or greenery are most commonly used and widely studied. However, the debate regarding the better implementation of cool and green technology is still ongoing. In this study, numerical sensitivity tests are carried out to evaluate the mitigation effect of the cool and green implementations at the city scale. The effects of roof-level and street-level implementations are compared in the context of a tropical urban environment.

  13. 城市范围绿色屋顶环境效益评价方法研究——以华盛顿市为例%Research on the Assessment Methods of Environmental Benefits for Green Roofs at Community-scale—A Case Study of Washington, D.C

    Institute of Scientific and Technical Information of China (English)

    牛皓; 周集体; Peter Adriaens

    2013-01-01

    分析华盛顿市绿色屋顶的环境效应(截留降水、节能、改善空气质量),对比绿色屋顶和传统屋顶的现值(PV),结果表明,在华盛顿市绿色规划下,40年后整个城市系统绿色屋顶的现值将比传统屋顶低30%-42%,相比单个建筑物范围又降低了3%-5%;同时绿色屋顶的投资回收期最快可以达到6-7年,相比单个建筑物范围提前1-2年.%Estimates stormwater retention, energy savings, and air quality improvement benefits for green roofs at community-scale in Washington, D.C., and incorporates these benefits into present value (PV) to make a comparative analysis with the conventional roofs. The results demonstrate that the PV of green roofs is 30%-42% less than that of conventional roofs at community-scale over 40 years, further reduces by 3%-5% comparing to that at building-scale. Lastly, the return period of investment of green roofs is expected at 6-7 years at community-scale, and further shortens 1-2 years comparing to that at building-scale.

  14. The green building envelope: vertical greening

    NARCIS (Netherlands)

    Ottelé, M.

    2011-01-01

    Planting on roofs and façades is one of the most innovative and fastest developing fields of green technologies with respect to the built environment and horticulture. This thesis is focused on vertical greening of structures and to the multi-scale benefits of vegetation. Vertical green can improve

  15. Comparison of Heat Resistance of Eight Kinds Of Roof Greening Woody Plant%8种屋顶绿化木本植物的耐热性比较

    Institute of Scientific and Technical Information of China (English)

    徐静平; 徐振华; 杜克久

    2011-01-01

    Screening woody plants to adapt to the roof special circumstances has important practical significance for riching the kinds of the greening plants and making it play the functions of roof greening and beautification.The high tempreture is the limited factor for plant growing.In order to expore the heat resistance of roof greening plants and study the adaptability of the plant to high temperature environments, Ulmus pumila L, Salix matsudana Koidz, Broussonetia papyrifera, Periploca sepium Bung., Populus simonii Carr., Lonicera maackii (Rupr.) Maxim.planted on the roof and Ulmus pumila cv.jinye, Sorbaria kirilowii (Reqel) Maxim.suitable for roof greening were as the test materials in the experiment.The relative conductivity of leaves of above plants were tested at different heat treatment conditions, and with Forstst 2.1 the heat resistance of the eight kinds of woody plants were studied.The results showed that: the temperature and cell injury rate of leaves treated with different high temperature were 'S' shaped curve.The semi-lethal temperature of different plants from high to low was Periploca sepium Bung., Periploca sepium Bung., Populus simonii Carr., Salix matsudana Koidz., Ulmus pumila L., Sorbaria kirilowii (Reqel) Maxim., Broussonetia papyrifera, Ulmus pumila cv.jinye, and which were 65.30℃, 63.80℃, 57.85℃, 56.84℃, 55.87℃, 49.94℃, 44.81℃, 43.98℃ respectively.The heat resistance of Periploca sepium Bung.and Lonicera maackii (Rupr.) Maxim.was best, that of Salix matsudana Koidz., Ulmus pumila L., Populus simonii Carr.was better, and that of Sorbaria kirilowii (Reqel) Maxim., Broussonetia papyrifera and Ulmus pumila cv.jinye were worst.%筛选适应屋顶特殊环境的木本植物,对于丰富屋顶绿化植物种类、发挥屋顶绿化的生态和美化功能具有重要的现实意义.高温胁迫是植物正常生长发育的限制因子,为了探索屋顶绿化木本植物的耐热性,研究其在屋顶高温环境下的适应能力,笔

  16. 屋顶绿化植物对废弃物转化基质的适应性研究%Study on the Adaptability of Plants for Roof Greening to Base Materials Transferred from Waste

    Institute of Scientific and Technical Information of China (English)

    周媛; 陈法志; 谭庆; 许林; 郭彩霞; 童俊; 戢小梅; 董艳芳

    2011-01-01

    [目的]研究屋顶绿化植物对废弃物转化基质的适应性.[方法]采用正交试验法,进行4因素3水平正交试验,以4种工农业废弃物粉煤灰、煤渣、秸秆和园林废弃物为基质,试验8种景天属植物的适应性情况.[结果]适宜屋顶绿化的废弃物转化基质配方为粉煤灰、煤渣、秸秆、园林废弃物,比例分别为1:1:1:1、1:2:2:2:2:1:2:1;8种景天属植物中佛甲草、垂盆草、宽叶佛甲草、德景天、费菜与八宝景天对废弃物转化基质适应性较强.[结论]废弃物转化基质应用于屋顶绿化中具有广阔的市场前景.%[ Objective ] To study the adaptability of roof greening plants in base materials transferred from waste. [ Method ] By applying the orthogonal test of 4 factors and 3 levels, 4 kinds of industrial and agricultural waste ( fly ash, slag, straw and waste of garden plants) are used to study the adaptability of 8 species of Sedum. [ Result] The proper volume ratio of fly ash, slag, straw and waste of garden plants for making suitable base materials were 1∶1∶ 1∶ 1, 1∶2∶ 2∶2 and 2∶ 1∶2∶ 1. Among the 8 test species, S. lineare, S. sarmentosum Bunge, S. hybridum Immergrunchett, S. aizoon and S. spectable Boreau are of higher adaptability to the base materials transferred from waste. [ Conclusion] The application of waste-transferred base materials enjoys a promising marketing future in roof greening.

  17. Green

    Institute of Scientific and Technical Information of China (English)

    孙继山

    2005-01-01

    The Green Games-this is a Chinese promise to the world. Green it has to be when the Olympic Games are opened at a spectacular venue in the north of Beijing in 2008. However, those who live in the capital still worry whether it will be possible to turn the rather polluted city. into a green or even half-green city. But time and again, China has proved that this kind of huge challenge can be met. Nevertheless,this time around it is a tough call indeed and a little over three years are left to execute and complete an audacious task.

  18. Collaborative active roof design

    NARCIS (Netherlands)

    Quanjel, E.M.C.J.

    2008-01-01

    Roofs play an essential role in buildings. Their value and impact often significantly surpass the cost ratio they represent in the total investment cost of the building. Traditionally, roofs have a protecting function and their basic design has changed little over hundreds of years. Nowadays

  19. Energy Performance Impacts from Competing Low-slope Roofing Choices and Photovoltaic Technologies

    Science.gov (United States)

    Nagengast, Amy L.

    With such a vast quantity of space, commercial low-slope roofs offer significant potential for sustainable roofing technology deployment. Specifically, building energy performance can be improved by installing rooftop energy technologies such as photovoltaic (PV) panels, and/or including designs such as white or green roofs instead of traditional black. This research aims to inform and support roof decisions through quantified energy performance impacts across roof choices and photovoltaic technologies. The primary dataset for this research was measured over a 16 month period (May 24, 2011 to October 13, 2012) from a large field experiment in Pittsburgh, Pennsylvania on top of a commercial warehouse with white, black and green roof sections, each with portions covered by polycrystalline photovoltaic panels. Results from the Pittsburgh experiment were extended to three different cities (San Diego, CA; Huntsville, AL; and Phoenix, AZ) chosen to represent a wide range of irradiance and temperature values. First, this research evaluated the difference in electricity production from a green-moss roof and black roof underneath photovoltaic panels to determine if the green roof's cooler air increases the panel efficiency. Second, separate studies examine 1) average hourly heat flux by month for unobstructed and shaded roof membranes 2) heat flux peak time delay, and 3) air temperature across roof types. Results of this research show green roofs slightly increased (0.8-1.5%) PV panel efficiency in temperatures approximately at or above 25° C (77°F) compared to black roofs. However in cool climates, like Pittsburgh, the roof type under the PV panels had little overall impact on PV performance when considering year round temperatures. Instead, roof decisions should place a stronger emphasis on heat flux impacts. The green roof outperformed both black and white roofs at minimizing total conductive heat flux. These heat flow values were used to develop a new, straight

  20. Inclusion of cool roofs in nonresidential Title 24 prescriptive requirements

    Energy Technology Data Exchange (ETDEWEB)

    Levinson, Ronnen; Akbari, Hashem; Konopacki, Steve; Bretz, Sarah

    2002-12-15

    Roofs that have high solar reflectance (high ability to reflect sunlight) and high thermal emittance (high ability to radiate heat) tend to stay cool in the sun. The same is true of low-emittance roofs with exceptionally high solar reflectance. Substituting a cool roof for a noncool roof tends to decrease cooling electricity use, cooling power demand, and cooling-equipment capacity requirements, while slightly increasing heating energy consumption. Cool roofs can also lower the ambient air temperature in summer, slowing ozone formation and increasing human comfort. DOE-2.1E building energy simulations indicate that use of a cool roofing material on a prototypical California nonresidential building with a low-sloped roof yields average annual cooling energy savings of approximately 300 kWh/1000 ft2 [3.2 kWh/m2], average annual natural gas deficits of 4.9 therm/1000 ft2 [5.6 MJ/m2], average source energy savings of 2.6 MBTU/1000 ft2 [30 MJ/m2], and average peak power demand savings of 0. 19 kW/1000 ft2 [2.1 W/m2]. The 15-year net present value (NPV) of energy savings averages $450/1000 ft2 [$4.90/m2] with time dependent valuation (TDV), and $370/1000 ft2 [$4.00/m2] without TDV. When cost savings from downsizing cooling equipment are included, the average total savings (15-year NPV + equipment savings) rises to $550/1000 ft2 [$5.90/m2] with TDV, and to $470/1000 ft2 [$5.00/m2] without TDV. Total savings range from 0.18 to 0.77 $/ft2 [1.90 to 8.30 $/m2] with TDV, and from 0.16 to 0.66 $/ft2 [1.70 to 7.10 $/m2] without TDV, across California's 16 climate zones. The typical cost premium for a cool roof is 0.00 to 0.20 $/ft2 [0.00 to 2.20 $/m2]. Cool roofs with premiums up to $0.20/ft2 [$2.20/m2] are expected to be cost effective in climate zones 2 through 16; those with premiums not exceeding $0.18/ft2 [$1.90/m2] are expected to be also cost effective in climate zone 1. Hence, this study recommends that the year-2005 California building energy efficiency code (Title

  1. Mine roof supports

    Energy Technology Data Exchange (ETDEWEB)

    Dettmers, M.; Peters, B.; Weirich, W.

    1983-12-27

    A mine roof support has hydraulic props mounted between a floor sill and a roof bar which can be raised and lowered by extension and retraction of the props. A goaf shield is pivotably connected to the rear of the roof bar and is linked via levers to the floor sill. A hydraulic piston and cylinder unit is connected between the roof bar and the goaf shield. Apparatus serves to prevent damage to the support components, and especially to the unit which could be extended beyond its full stroke when the props are retracted to bring the goaf shield and the roof bar more or less into alignment. The protective apparatus is composed of a compact valve device operated by a member, such as a cam, to block the props from hydraulic pressure when the goaf shield and the roof bar assume a pre-determined angular disposition. Both the valve device and its operating member are disposed in a protected position within chambers formed inside the roof bar and the goaf shield adjacent the pivot connection therebetween.

  2. Norwegian Pitched Roof Defects

    Directory of Open Access Journals (Sweden)

    Lars Gullbrekken

    2016-06-01

    Full Text Available The building constructions investigated in this work are pitched wooden roofs with exterior vertical drainpipes and wooden load-bearing system. The aim of this research is to further investigate the building defects of pitched wooden roofs and obtain an overview of typical roof defects. The work involves an analysis of the building defect archive from the research institute SINTEF Building and Infrastructure. The findings from the SINTEF archive show that moisture is a dominant exposure factor, especially in roof constructions. In pitched wooden roofs, more than half of the defects are caused by deficiencies in design, materials, or workmanship, where these deficiencies allow moisture from precipitation or indoor moisture into the structure. Hence, it is important to increase the focus on robust and durable solutions to avoid defects both from exterior and interior moisture sources in pitched wooden roofs. Proper design of interior ventilation and vapour retarders seem to be the main ways to control entry from interior moisture sources into attic and roof spaces.

  3. greening

    African Journals Online (AJOL)

    Utpal

    Results reveal that sodium sulphite method of DNA isolation provided higher yield and ... rescence tests with monoclonal antibodies and DNA-DNA hybridization with .... Validation of PCR for detection of greening bacterium. Following the ...

  4. Adaptable typologies for active roofs

    NARCIS (Netherlands)

    Quanjel, E.M.C.J.; Zeiler, W.

    2006-01-01

    The main objective of this part of the 6th framework Pan-European EUR-ACTIVE ROOF-er project is to improve the interaction between design participants of dynamic adaptable Active Roofs in product development and Active Roofs from an architects/ customers perspective. Improvements in Active Roof desi

  5. Homogeneous M2 duals

    CERN Document Server

    Figueroa-O'Farrill, José

    2015-01-01

    Motivated by the search for new gravity duals to M2 branes with $N>4$ supersymmetry --- equivalently, M-theory backgrounds with Killing superalgebra $\\mathfrak{osp}(N|4)$ for $N>4$ --- we classify (except for a small gap) homogeneous M-theory backgrounds with symmetry Lie algebra $\\mathfrak{so}(n) \\oplus \\mathfrak{so}(3,2)$ for $n=5,6,7$. We find that there are no new backgrounds with $n=6,7$ but we do find a number of new (to us) backgrounds with $n=5$. All backgrounds are metrically products of the form $\\operatorname{AdS}_4 \\times P^7$, with $P$ riemannian and homogeneous under the action of $\\operatorname{SO}(5)$, or $S^4 \\times Q^7$ with $Q$ lorentzian and homogeneous under the action of $\\operatorname{SO}(3,2)$. At least one of the new backgrounds is supersymmetric (albeit with only $N=2$) and we show that it can be constructed from a supersymmetric Freund--Rubin background via a Wick rotation. Two of the new backgrounds have only been approximated numerically.

  6. Life-cycle cost-benefit analysis of extensive vegetated roof systems.

    Science.gov (United States)

    Carter, Timothy; Keeler, Andrew

    2008-05-01

    The built environment has been a significant cause of environmental degradation in the previously undeveloped landscape. As public and private interest in restoring the environmental integrity of urban areas continues to increase, new construction practices are being developed that explicitly value beneficial environmental characteristics. The use of vegetation on a rooftop--commonly called a green roof--as an alternative to traditional roofing materials is an increasingly utilized example of such practices. The vegetation and growing media perform a number of functions that improve environmental performance, including: absorption of rainfall, reduction of roof temperatures, improvement in ambient air quality, and provision of urban habitat. A better accounting of the green roof's total costs and benefits to society and to the private sector will aid in the design of policy instruments and educational materials that affect individual decisions about green roof construction. This study uses data collected from an experimental green roof plot to develop a benefit cost analysis (BCA) for the life cycle of extensive (thin layer) green roof systems in an urban watershed. The results from this analysis are compared with a traditional roofing scenario. The net present value (NPV) of this type of green roof currently ranges from 10% to 14% more expensive than its conventional counterpart. A reduction of 20% in green roof construction cost would make the social NPV of the practice less than traditional roof NPV. Considering the positive social benefits and relatively novel nature of the practice, incentives encouraging the use of this practice in highly urbanized watersheds are strongly recommended.

  7. The green building envelope: vertical greening

    OpenAIRE

    Ottelé, M.

    2011-01-01

    Planting on roofs and façades is one of the most innovative and fastest developing fields of green technologies with respect to the built environment and horticulture. This thesis is focused on vertical greening of structures and to the multi-scale benefits of vegetation. Vertical green can improve the environment in urban areas and is becoming a key design consideration in modern building developments. Vertical greening of structures offers large surfaces with vegetation and at the same time...

  8. The effect of roofing material on the quality of harvested rainwater.

    Science.gov (United States)

    Mendez, Carolina B; Klenzendorf, J Brandon; Afshar, Brigit R; Simmons, Mark T; Barrett, Michael E; Kinney, Kerry A; Kirisits, Mary Jo

    2011-02-01

    Due to decreases in the availability and quality of traditional water resources, harvested rainwater is increasingly used for potable and non-potable purposes. In this study, we examined the effect of conventional roofing materials (i.e., asphalt fiberglass shingle, Galvalume(®) metal, and concrete tile) and alternative roofing materials (i.e., cool and green) on the quality of harvested rainwater. Results from pilot-scale and full-scale roofs demonstrated that rainwater harvested from any of these roofing materials would require treatment if the consumer wanted to meet United States Environmental Protection Agency primary and secondary drinking water standards or non-potable water reuse guidelines; at a minimum, first-flush diversion, filtration, and disinfection are recommended. Metal roofs are commonly recommended for rainwater harvesting applications, and this study showed that rainwater harvested from metal roofs tends to have lower concentrations of fecal indicator bacteria as compared to other roofing materials. However, concrete tile and cool roofs produced harvested rainwater quality similar to that from the metal roofs, indicating that these roofing materials also are suitable for rainwater harvesting applications. Although the shingle and green roofs produced water quality comparable in many respects to that from the other roofing materials, their dissolved organic carbon concentrations were very high (approximately one order of magnitude higher than what is typical for a finished drinking water in the United States), which might lead to high concentrations of disinfection byproducts after chlorination. Furthermore the concentrations of some metals (e.g., arsenic) in rainwater harvested from the green roof suggest that the quality of commercial growing media should be carefully examined if the harvested rainwater is being considered for domestic use. Hence, roofing material is an important consideration when designing a rainwater catchment.

  9. Urban heat mitigation by roof surface materials during the East Asian summer monsoon

    Science.gov (United States)

    Lee, Seungjoon; Ryu, Youngryel; Jiang, Chongya

    2015-12-01

    Roof surface materials, such as green and white roofs, have attracted attention in their role in urban heat mitigation, and various studies have assessed the cooling performance of roof surface materials during hot and sunny summer seasons. However, summers in the East Asian monsoon climate region are characterized by significant fluctuations in weather events, such as dry periods, heatwaves, and rainy and cloudy days. This study investigated the efficacy of different roof surface materials for heat mitigation, considering the temperatures both at and beneath the surface of the roof covering materials during a summer monsoon in Seoul, Korea. We performed continuous observations of temperature at and beneath the surface of the roof covering materials, and manual observation of albedo and the normalized difference vegetation index for a white roof, two green roofs (grass (Poa pratensis) and sedum (Sedum sarmentosum)), and a reference surface. Overall, the surface temperature of the white roof was significantly lower than that of the grass and sedum roofs (1.1 °C and 1.3 °C), whereas the temperature beneath the surface of the white roof did not differ significantly from that of the grass and sedum roofs during the summer. The degree of cloudiness significantly modified the surface temperature of the white roof compared with that of the grass and sedum roofs, which depended on plant metabolisms. It was difficult for the grass to maintain its cooling ability without adequate watering management. After considering the cooling performance and maintenance efforts for different environmental conditions, we concluded that white roof performed better in urban heat mitigation than grass and sedum during the East Asian summer monsoon. Our findings will be useful in urban heat mitigation in the region.

  10. Effect of Turf Roof Slabs on Indoor Thermal Performance in Tropical Climates: A Life Cycle Cost Approach

    Directory of Open Access Journals (Sweden)

    R. U. Halwatura

    2013-01-01

    Full Text Available Urbanization related to population growth is one of the burning issues that the world is facing today. Parallel to this, there is visible evidence of a possible energy crisis in the near future. Thus, scientists have paid attention to sustainable development methods, and in the field of building construction also, several innovations have been proposed. For example, green roof concept is one of such which is considered a viable method mainly to reduce urban heat island effect, to regain lost land spaces in cities, and to increase aesthetics in cities. The present study was aimed at investigating the impact of green roofs on indoor temperature of buildings, the effect of different types of roofs on the air conditioning loads, and the life cycle cost of buildings with different types of roofing. The study was conducted in several phases: initial small-scale models to determine the heat flow characteristics of roof top soil layers with different thicknesses, a large-scale model applying the findings of the small-scale models to determine temperature fluctuations within a building with other common roofing systems, a computer simulation to investigate air conditioning loads in a typical building with cement fiber sheets and green roof slabs, a comparative analysis of the effect of traditional type roofs and green roofs on the air conditioning loads, and finally an analysis to predict the influence of traditional type roofs and green roofs on life cycle cost of the buildings. The main findings of the study were that green roofs are able to reduce the indoor temperature of buildings and are able to achieve better heat transfer through the roof, and, thus a lower cooling load is necessary for air conditioning and has the possibility of reducing life cycle cost of a building.

  11. Evolution of Flat Roofs

    Directory of Open Access Journals (Sweden)

    Şt. Vasiliu

    2009-01-01

    Full Text Available Roofs are constructive subassembles that are located at the top of buildings, which toghether with perimetral walls and some elements of the infrastructure belongs to the subsystem elements that close the building. Roofs must meet resistance requirements to mechanical action, thermal insulating, waterproofing and acoustic, fire resistance, durability, economy and aesthetics. The man saw the need to build roofs from the oldest ancient times. Even if the design of buildings has an empirical character, are known and are preserved until today constructions that are made in antiquity, by the Egyptians, Greeks and Romans with architectural achievements, worthy of admiration and in present time. General composition of civil construction has been influenced throughout the evolution of construction history by the level of production forces and properties of building materials available in every historical epoch. For over five millennia, building materials were stone, wood and ceramic products (concrete was used by theRomans only as filling material.

  12. green

    Directory of Open Access Journals (Sweden)

    Elena Grigoryeva

    2011-02-01

    Full Text Available The “green” topic follows the “youngsters”, which is quite natural for the Russian language.Traditionally these words put together sound slightly derogatory. However, “green” also means fresh, new and healthy.For Russia, and for Siberia in particular, “green” architecture does sound new and fresh. Forced by the anxious reality, we are addressing this topic intentionally. The ecological crisis, growing energy prices, water, air and food deficits… Alexander Rappaport, our regular author, writes: “ It has been tolerable until a certain time, but under transition to the global civilization, as the nature is destroyed, and swellings of megapolises expand incredibly fast, the size and the significance of all these problems may grow a hundredfold”.However, for this very severe Siberian reality the newness of “green” architecture may turn out to be well-forgotten old. A traditional Siberian house used to be built on principles of saving and environmental friendliness– one could not survive in Siberia otherwise.Probably, in our turbulent times, it is high time to fasten “green belts”. But we should keep from enthusiastic sticking of popular green labels or repainting of signboards into green color. We should avoid being drowned in paper formalities under “green” slogans. And we should prevent the Earth from turning into the planet “Kin-dza-dza”.

  13. Drawing green in New York city : aesthetic design and sustainable development

    Energy Technology Data Exchange (ETDEWEB)

    Wayland-Smith, S. [Balmori Associates Inc., New York, NY (United States)

    2005-07-01

    Strong aesthetic design can advance the development of the green roof industry in the United States. Many architects are beginning to adopt green roofs as a design element that merges architecture and landscapes in sustainable systems. Innovative design of green roofs will draw attention to the technology and create momentum for the green roof movement, which may lead to more incentives and policy programs. With the development of a range of watertight membranes, geotextiles and specific soil substrates, the idea of merging landscape and architecture within a single structure is now a more viable and efficient reality. Design intent needs to be clearly illustrated. This paper provided an outline of the philosophy and practices of Balmori, a green roof design firm that envisions the rooftops of New York City as a potential second central park. Green roofs designed by the organization to date include the Solaire building roof garden; a green roof network in Long Island; the Gratz Industries and Silvercup Studios roof projects; and a new residential green roof for a building in Manhattan. Details of funding, partnerships and technical specifications were provided for each project. Descriptions of the completed and ongoing projects were used to illustrate Balmori's philosophy of promoting sustainable green roofs that alter their urban context through aesthetic means. It was concluded that it is only when green roof technologies are conceived as being powerful design tools as opposed to ecological experiments will their widespread adoption occur.1 ref., 4 figs.

  14. Design methodology for innovative roofs

    NARCIS (Netherlands)

    Quanjel, E.M.C.J.; Zeiler, W.; Trum, H.M.G.J.

    2006-01-01

    Traditional roofs have primary, passive, functions such as protection against rain, wind, snow etc.. Nowadays, roofs are increasingly used as preferred location for additional functions such as photovoltaic systems, roof lights and safety devices. New approaches, on designing as well as assembling t

  15. 碎砖和陶粒配制的拓展型屋顶绿化基材栽种景天植物对比试验%Comparative Study on Planting Sedum Plants in Extensive Green Roof Substrates Made of Crushed Brick and Ceramsite

    Institute of Scientific and Technical Information of China (English)

    叶建军; 朱兆华; 魏道江; 肖衡林; 徐国钢; 梁世庆

    2016-01-01

    Objective] T he objective of the study is to compare the effects of planting sedum plants in green roof substrates made of crushed brick and ceramsite in order to provide the reference for related research . [Methods] With two types of extensive green roof substrate mixed by using 5% distillers'grains ,10% top soil ,25% sand ,compound fertilizer (4 kg/m3 ) and 60% ceramsite ,or 55% crushed brick and 5% lime stone ,we planted two popular Sedum species (Sedum sarmentosum ,SS ;Sedum Linare ,SL) in them ,and then investigated coverage and dry weights of plants ,and nutrient content(total nitrogen ,TN ;total phos‐phorus ,TP;and total kalium ,TK) in substrate within 18 months .[Results] Plant coverage and dry weights from substrate made of crushed brick were greater or equal to those from substrate made of ceram‐site ,while the decreases of TP and TK in two substrates did not differ from each other significantly ,TN in substrate made of crushed brick reduced less than substrate made of ceramsite .The coverage and dry weights of SS were significantly higher than those of SL .[Conclusion] Green roof plants grow better in the green roof substrate made of crushed brick than substrate made of ceramsite ,and thus can replace ceramsite in mix‐ing green roof substrate .%[目的]对比建筑垃圾和陶粒配制的拓展型屋顶绿化基材栽种景天植物的效果,为相关的研究提供参考。[方法]采用酒糟(5%)、表土(10%)、河沙(25%)、复合肥(4 kg/m3)以及60%陶粒或55%碎砖、5%碎石灰石配制的2种屋顶绿化基材,现场栽种2种流行的景天植物垂盆草(Sedum Sarmentosum )和佛甲草(Sedum Linare);在18个月内考察植物盖度、植物干重、基材养分含量的变化。[结果]建筑垃圾基材栽种的植物的盖度和干重大于或等于陶粒基材;建筑垃圾基材的磷、钾养分含量减少与陶粒基材无显著差异,氮养分含量减少量小于陶粒基材;

  16. Potted Plants on Flat Roof as a Strategy to Reduce Indoor Temperature in Malaysian Climate

    Directory of Open Access Journals (Sweden)

    Asmat Ismail

    2010-01-01

    Full Text Available Problem statement: The phenomenon of global warming or climate change has led to many environmental issues including higher atmospheric temperatures, intensive precipitation, increase greenhouse gaseous emission and of course increase indoor discomfort condition. Researchers worldwide collectively agreed that one way of reducing the impact of global warming is by implementing green roof technology which integrates vegetation, growing medium and water proofing membrane on top of the roof surface. However, none of them have ever studied on how much the potted plants on the roof top could contribute to lessen the environmental problems. Therefore, this study investigates the effect of potted plants on flat roof on the indoor temperature inside building in Malaysian climate. Approach: This study emphasized on experimental approach of the room with flat roof. Measurements were conducted in two phases i.e., room with potted plant on the roof and room with bare roof. The measurements were conducted on the same room. Results: The experiment showed a promising result whereby the average indoor temperature dropped between 0.21 and 1.73°C had been observed during the measurements, while average indoor surface temperatures difference between roof with potted plants and bare roof of 7.86°C had been recorded during daytime hour. Conclusion: Potted plants on flat roof had a great potential in reducing the indoor temperature of the room underneath and could contributed to the reduction of energy consumption in building.

  17. Producing superhydrophobic roof tiles

    Science.gov (United States)

    Carrascosa, Luis A. M.; Facio, Dario S.; Mosquera, Maria J.

    2016-03-01

    Superhydrophobic materials can find promising applications in the field of building. However, their application has been very limited because the synthesis routes involve tedious processes, preventing large-scale application. A second drawback is related to their short-term life under outdoor conditions. A simple and low-cost synthesis route for producing superhydrophobic surfaces on building materials is developed and their effectiveness and their durability on clay roof tiles are evaluated. Specifically, an organic-inorganic hybrid gel containing silica nanoparticles is produced. The nanoparticles create a densely packed coating on the roof tile surface in which air is trapped. This roughness produces a Cassie-Baxter regime, promoting superhydrophobicity. A surfactant, n-octylamine, was also added to the starting sol to catalyze the sol-gel process and to coarsen the pore structure of the gel network, preventing cracking. The application of ultrasound obviates the need to use volatile organic compounds in the synthesis, thereby making a ‘green’ product. It was also demonstrated that a co-condensation process effective between the organic and inorganic species is crucial to obtain durable and effective coatings. After an aging test, high hydrophobicity was maintained and water absorption was completely prevented for the roof tile samples under study. However, a transition from a Cassie-Baxter to a Wenzel state regime was observed as a consequence of the increase in the distance between the roughness pitches produced by the aging of the coating.

  18. The impact of roofing material on building energy performance

    Science.gov (United States)

    Badiee, Ali

    , fenestration, etc. and their thermal insulation energy performance value will not be included this study. Five different UAB campus buildings with the same reinforced concrete structure (RC Structure), each having a different roofing material were selected, surveyed, analyzed, and evaluated in this study. Two primary factors are considered in this evaluation: the energy consumption and utility bills. The data has been provided by the UAB Facilities Management Department and has been monitored from 2007 to 2013 using analysis of variance (ANOVA) and t-test methods. The energy utilities examined in this study involved electricity, domestic water, and natural gas. They were measured separately in four different seasons over a seven-year time period. The building roofing materials consisted of a green roof, a white (reflective) roof, a river rock roof, a concrete paver roof, and a traditional black roof. Results of the tested roofs from this study indicate that the white roof is the most energy efficient roofing material.

  19. Predictive Service Life Tests for Roofing Membranes: Phase II Investigation of Accelerated Aging Tests for Tracking Degradation of Roofing Membrane Materials

    Science.gov (United States)

    2002-09-01

    bitumen 2 ply SBS modified bitumen G H J K L M 2 ply APP modified bitumen 2 ply APP modified bitumen 1 ply EPDM, nonreinforced 1 ply EPDM...chloride] (PVC), and modified bitumen (MB) roofing systems, the Army currently uses these materials on all types of low-slope applications. Even when...asphalt built-up roofing (BUR), poly [vinyl choloride] (PVC,) styrene-butadiene-styrene ( SBS ) modified bi- tumen (MB), atactic polypropylene (APP) MB

  20. Highly Reflective Roofing Sheets Installed on a School Building to Mitigate the Urban Heat Island Effect in Osaka

    Directory of Open Access Journals (Sweden)

    Jihui Yuan

    2016-05-01

    Full Text Available Currently, strategies to mitigate urban heat island (UHI effects and reduce building energy consumption are implemented worldwide. In Japan, as an effective means of mitigating UHI effects and saving energy of buildings, highly reflective (HR roofs have increasingly been used. In this study, in order to evaluate the effect of HR roofs on building energy conservation, we investigated the solar reflectivity of a subject school roof in Osaka, Japan, in which HR roofing sheets were installed on the roof from 2010. Additionally, monthly and annual thermal loads, including the cooling load and heating load of the top floor of the school, were calculated using the thermal load calculation software New HASP/ACLD-β. Comparing the calculated thermal loads of the school after HR roofing sheet installation to before, the annual thermal load decreased about 25 MJ/m2/year, and the cooling load decreased about 112 MJ/m2/year. However, the heating load increased about 87 MJ/m2/year in winter. To minimize the annual thermal load, thermal insulation of the roof was also considered to be used together with HR roofing sheets. Thermal load calculations showed that the combination of HR roofing sheets and thermal insulation can be effective in further reducing the annual thermal load.

  1. A School on Roof

    Institute of Scientific and Technical Information of China (English)

    ZhouChao

    2005-01-01

    March 23, Wednesday, Wuhan. It was a raining and cloudy day. One month passed but still more than 20 students had yet registered in Lingzhi Elementary School in Jianghan District, Wuhan, capital city of central Hubei Province. Zhu Zhongfan habitually looked out to the stairway of the building. “Whenever a new semester begins, a dozen of students will not come. They either go back to their hometowns or transfer to other school or even drop out.” Zhu, 49 years old, is the headmaster of the school. He began teaching at 19 and founded this school in 1999. Currently, there are 406 registered students, most of which are children of migrant workers from the countryside. As it is extremely hard to find a cheap place for school, Zhu had to locate his school on the roof of a vegetable fair building. Everyday, student's reciting of textbooks mixes with shouting of vendors, orchestrating unique symphonic melodies.

  2. Green towers and green walls

    Energy Technology Data Exchange (ETDEWEB)

    Sharp, R. [Sharp and Diamond Landscape Architecture and Planning, Vancouver, BC (Canada)

    2006-07-01

    North American cities face many major environmental and health issues such as urban heat island effect, the intensity of storms, microclimate around buildings, imperviousness of sites, poor air quality and increases in respiratory disease. Several new technologies are starting to address global impacts and community level issues as well as the personal health and comfort of building occupants. These include green towers, living walls, vegetated rooftops and ecological site developments. This paper examined these forms of eco-development and presented their benefits. It discussed green walls in Japan; green towers in Malaysia, Singapore and Great Britain; green facades of climbing plants; active living walls in Canada; and passive living walls in France and Canada. It also discussed thermal walls; thematic walls; vertical gardens and structured wildlife habitat. Last, it presented testing, monitoring, research and conclusions. The Centre for the Advancement of Green Roof Technology is setting up a program to test thermal performance, to assess plant survival and to monitor green walls at the British Columbia Institute of Technology in Vancouver, Canada as much of the research out of Japan is only available in Japanese script. It was concluded that green architecture can provide shade, food, rainwater, shelter for wildlife and mimic natural systems. 15 refs.

  3. Thermal Performance of Building Roof with Infrared Reflective Coatings

    Institute of Scientific and Technical Information of China (English)

    SHEN Hui; TAN Hong-wei; KATSUO MIKI; LIU Xiao-yu

    2009-01-01

    This paper investigated the applicability and effects of infrared reflective coating on energy con-sumption of factory building in hot summer and warm winter zone. It first resorted to theoretical calculation, which demonstrated the beneficial effects of infrared reflective coating on reducing building energy consumption. Then it analyzed a field measurement done on two identical rooms respectively with ordinary coated roof and in-frared reflective coated roof from November 2006 to October 2007, on a 24h basis. The measured data include exterior and interior roof surface temperature, indoor air temperature, and indoor globe temperature. The relat-ed weather data is from a weather station near the measured area. The continuous measurement has been accom-plished in southern China, and the measured data indicate that roof surface temperature and heat gain are signifi-cantly decreased in summer while slight negative effects in winter are induced by adopting infrared reflective coating. Thus it is simple and applicable to reduce building energy consumption in this area by applying infrared reflective coating. Regress equation between reduced roof thermal property, such as surface temperature and heat gain, and reduction in absorbed solar radiation shows their highly linear relationship. Based on the mea-sured data, it is estimated that the reduced power consumption is 3.45 kWh/m2·month in June.

  4. 30 CFR 75.205 - Installation of roof support using mining machines with integral roof bolters.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Installation of roof support using mining machines with integral roof bolters. 75.205 Section 75.205 Mineral Resources MINE SAFETY AND HEALTH... Roof Support § 75.205 Installation of roof support using mining machines with integral roof bolters...

  5. Using Remote Sensing to Quantify Roof Albedo in Seven California Cities

    Science.gov (United States)

    Ban-Weiss, G. A.; Woods, J.; Millstein, D.; Levinson, R.

    2013-12-01

    Cool roofs reflect sunlight and therefore can reduce cooling energy use in buildings. Further, since roofs cover about 20-25% of cities, wide spread deployment of cool roofs could mitigate the urban heat island effect and partially counter urban temperature increases associated with global climate change. Accurately predicting the potential for increasing urban albedo using reflective roofs and its associated energy use and climate benefits requires detailed knowledge of the current stock of roofs at the city scale. Until now this knowledge has been limited due to a lack of availability of albedo data with sufficient spatial coverage, spatial resolution, and spectral information. In this work we use a novel source of multiband aerial imagery to derive the albedos of individual roofs in seven California cities: Los Angeles, Long Beach, San Diego, Bakersfield, Sacramento, San Francisco, and San Jose. The radiometrically calibrated, remotely sensed imagery has high spatial resolution (1 m) and four narrow (less than 0.1 μm wide) band reflectances: blue, green, red, and near-infrared. To derive the albedo of roofs in each city, we first locate roof pixels within GIS building outlines. Next we use laboratory measurements of the solar spectral reflectances of 190 roofing products to empirically relate solar reflectance (albedo) to reflectances in the four narrow bands; the root-mean-square of the residuals for the albedo prediction is 0.016. Albedos computed from remotely sensed reflectances are calibrated to ground measurements of roof albedo in each city. The error (both precision and accuracy) of albedo values is presented for each city. The area-weighted mean roof albedo (× standard deviation) for each city ranges from 0.17 × 0.08 (Los Angeles) to 0.29 × 0.15 (San Diego). In each city most roofs have low albedo in the range of 0.1 to 0.3. Roofs with albedo greater than 0.4 comprise less than 3% of total roofs and 7% of total roof area in each city. The California

  6. An Evaluation of Vegetated Roofing Technology: Application at Air Force Plant Four, Building 15

    Science.gov (United States)

    2004-03-01

    Commission on Environment and Development (The Brundtland Commission), sustainable development is “the capacity to meet the needs of the present without...validates the reports of slower flow rates of storm water runoff from a green roof as opposed to a conventional roof. The slower flow rates reduce the...experts report actual energy savings for a facility are likely to be approximately 25% (Scholz-Barth, 2001:4; Perry, 2003a). The most conservative

  7. Evaluation of energy roof direct utilization

    Energy Technology Data Exchange (ETDEWEB)

    Lazzarin, R.; Rossetto, L.; Viero, L.

    1984-04-01

    Energy roofs are roofing systems equipped with channels which allow both solar and atmospheric energy collection. They were conceived as cold source for heat pump systems. The behavious of an energy roof in DHW direct heating was studied; this might extend energy roof utilization all year long. The estimates were performed through more reliable recently proposed correlations for wind convection heat transfer coefficients. The advantage of annual energy roof utilization in DHW direct heating is predictable.

  8. Green nanotechnology

    Science.gov (United States)

    Smith, Geoff B.

    2011-10-01

    Nanotechnology, in particular nanophotonics, is proving essential to achieving green outcomes of sustainability and renewable energy at the scales needed. Coatings, composites and polymeric structures used in windows, roof and wall coatings, energy storage, insulation and other components in energy efficient buildings will increasingly involve nanostructure, as will solar cells. Nanostructures have the potential to revolutionize thermoelectric power and may one day provide efficient refrigerant free cooling. Nanomaterials enable optimization of optical, opto-electrical and thermal responses to this urgent task. Optical harmonization of material responses to environmental energy flows involves (i) large changes in spectral response over limited wavelength bands (ii) tailoring to environmental dynamics. The latter includes engineering angle of incidence dependencies and switchable (or chromogenic) responses. Nanomaterials can be made at sufficient scale and low enough cost to be both economic and to have a high impact on a short time scale. Issues to be addressed include human safety and property changes induced during manufacture, handling and outdoor use. Unexpected bonuses have arisen in this work, for example the savings and environmental benefits of cool roofs extend beyond the more obvious benefit of reduced heat flows from the roof into the building.

  9. Between green and grey

    NARCIS (Netherlands)

    Jeanet Kullberg

    2016-01-01

    Original title: Tussen groen en grijs Taking cuttings is cool. Growing vegetables is all the rage. Green oases can now be found scattered throughout Dutch towns and cities: community gardens and roof gardens where residents can go to relax and enjoy themselves, improve the appearance of their neigh

  10. Between green and grey

    NARCIS (Netherlands)

    Jeanet Kullberg

    2016-01-01

    Taking cuttings is cool. Growing vegetables is all the rage. Green oases can now be found scattered throughout Dutch towns and cities: community gardens and roof gardens where residents can go to relax and enjoy themselves, improve the appearance of their neighbourhood and meet their fellow resident

  11. Advanced Energy Efficient Roof System

    Energy Technology Data Exchange (ETDEWEB)

    Jane Davidson

    2008-09-30

    Energy consumption in buildings represents 40 percent of primary U.S. energy consumption, split almost equally between residential (22%) and commercial (18%) buildings.1 Space heating (31%) and cooling (12%) account for approximately 9 quadrillion Btu. Improvements in the building envelope can have a significant impact on reducing energy consumption. Thermal losses (or gains) from the roof make up 14 percent of the building component energy load. Infiltration through the building envelope, including the roof, accounts for an additional 28 percent of the heating loads and 16 percent of the cooling loads. These figures provide a strong incentive to develop and implement more energy efficient roof systems. The roof is perhaps the most challenging component of the building envelope to change for many reasons. The engineered roof truss, which has been around since 1956, is relatively low cost and is the industry standard. The roof has multiple functions. A typical wood frame home lasts a long time. Building codes vary across the country. Customer and trade acceptance of new building products and materials may impede market penetration. The energy savings of a new roof system must be balanced with other requirements such as first and life-cycle costs, durability, appearance, and ease of construction. Conventional residential roof construction utilizes closely spaced roof trusses supporting a layer of sheathing and roofing materials. Gypsum board is typically attached to the lower chord of the trusses forming the finished ceiling for the occupied space. Often in warmer climates, the HVAC system and ducts are placed in the unconditioned and otherwise unusable attic. High temperature differentials and leaky ducts result in thermal losses. Penetrations through the ceilings are notoriously difficult to seal and lead to moisture and air infiltration. These issues all contribute to greater energy use and have led builders to consider construction of a conditioned attic. The

  12. Garden roof in the southwest for environmental benefits : the School of Public Health

    Energy Technology Data Exchange (ETDEWEB)

    Schaack, K.A. [Roof Consultants Inst., Raleigh, NC (United States). Green Roof Research Committee]|[Roofing Contractors Assoc. of Texas, Pflugerville, TX (United States)]|[Gulf Coast Roof Management Inst., Houston, TX (United States)

    2004-07-01

    . Random watering was performed to help establish the various plants. The progress of the plants was monitored to determine the best suited plants for this application according to weather characteristics of Houston in terms of high humidity, high heat, pollution, and torrential downpours. The primary benefits include heat load reduction, roof membrane protection, and water run-off control. Other benefits provided by this garden roof were better air quality, creating green space, and offering an instrument for education to increase public awareness of green roof technology. 4 tabs., 21 figs.

  13. Brownfields Tabor Commons Green Jobs Training Program

    Science.gov (United States)

    This training curriculum is designed to inform entry level tradeswomen about the green job opportunities in areas such as deconstruction, weatherization, eco or solar roofing, stormwater systems and more.

  14. Rams Head Center : an innovative vegetative roof plaza at the University of North Carolina

    Energy Technology Data Exchange (ETDEWEB)

    Adams, M.; Potts, A. [Cahill Associates Inc., West Chester, PA (United States)

    2006-07-01

    A newly constructed vegetative roof plaza on the University of North Carolina Chapel Hill campus serves as a link between 2 sides of the campus. The multi-use Rams Head Center is a green roof plaza constructed over a large parking garage. As part of the campus's expansion plans, the University set rigorous environmental goals, such as balancing growth with preservation of natural drainage systems; managing stormwater as an opportunity instead of a problem; managing total stormwater volume on-site; enhancing and protecting the water quality of streams; and, reinforcing the University as a role model. During large storms, the entire green roof system discharges into a bioswale, a stormwater infiltration bed, and a recreated stream segment. The 40,000 square foot green roof plaza includes a 56,000 gallon cistern and a permanent water storage zone under the planting soil to support trees and shrubs. Visual stormwater connections and signs are placed to raise community awareness of water resource issues. This paper reviewed the basic design principles for the remainder of non-cistern areas of the green roof. Issues regarding landscape design, seasonal operation and maintenance were also discussed. 7 refs., 14 figs.

  15. Advanced Energy Efficient Roof System

    Energy Technology Data Exchange (ETDEWEB)

    Jane Davidson

    2008-09-30

    Energy consumption in buildings represents 40 percent of primary U.S. energy consumption, split almost equally between residential (22%) and commercial (18%) buildings.1 Space heating (31%) and cooling (12%) account for approximately 9 quadrillion Btu. Improvements in the building envelope can have a significant impact on reducing energy consumption. Thermal losses (or gains) from the roof make up 14 percent of the building component energy load. Infiltration through the building envelope, including the roof, accounts for an additional 28 percent of the heating loads and 16 percent of the cooling loads. These figures provide a strong incentive to develop and implement more energy efficient roof systems. The roof is perhaps the most challenging component of the building envelope to change for many reasons. The engineered roof truss, which has been around since 1956, is relatively low cost and is the industry standard. The roof has multiple functions. A typical wood frame home lasts a long time. Building codes vary across the country. Customer and trade acceptance of new building products and materials may impede market penetration. The energy savings of a new roof system must be balanced with other requirements such as first and life-cycle costs, durability, appearance, and ease of construction. Conventional residential roof construction utilizes closely spaced roof trusses supporting a layer of sheathing and roofing materials. Gypsum board is typically attached to the lower chord of the trusses forming the finished ceiling for the occupied space. Often in warmer climates, the HVAC system and ducts are placed in the unconditioned and otherwise unusable attic. High temperature differentials and leaky ducts result in thermal losses. Penetrations through the ceilings are notoriously difficult to seal and lead to moisture and air infiltration. These issues all contribute to greater energy use and have led builders to consider construction of a conditioned attic. The

  16. Sloped Roof Conversions for Small, Flat-Roof Buildings.

    Science.gov (United States)

    1984-12-01

    co solve other, unrelated Table 5 List of Contacts Involved in Roof Conversion Projects California AEP-Span, San Diego Florida Duval County...Survlvablllty Section, CCB-CPS Infrastructure Branch, LANDA HQ UsaUCOH 09128 ATTN: ECJ 4/7-LOE Fort Belvoir, VA 22060 (7) ATTN

  17. Evaluation of Roof Bolting Requirements Based on In-Mine Roof Bolter Drilling

    Energy Technology Data Exchange (ETDEWEB)

    Syd S. Peng

    2005-10-01

    Roof bolting is the most popular method for underground openings in the mining industry, especially in the bedded deposits such as coal. In fact, all U.S. underground coal mine entries are roof-bolted as required by law. However, roof falls still occur frequently in the roof bolted entries. The two possible reasons are: the lack of knowledge of and technology to detect the roof geological conditions in advance of mining, and lack of roof bolting design criteria for modern roof bolting systems. This research is to develop a method for predicting the roof geology and stability condition in real time during roof bolting operation. Based on this information, roof bolting design criteria for modern roof bolting systems will be developed for implementation in real time. For the prediction of roof geology and stability condition in real time, a micro processor was used and a program developed to monitor and record the drilling parameters of roof bolter. These parameters include feed pressure, feed flow (penetration rate), rotation pressure, rotation rate, vacuum pressure, oil temperature of hydraulic circuit, and signals for controlling machine. From the results of a series of laboratory and underground tests so far, feed pressure is found to be a good indicator for identifying the voids/fractures and estimating the roof rock strength. The method for determining quantitatively the location and the size of void/fracture and estimating the roof rock strength from the drilling parameters of roof bolter was developed. Also, a set of computational rules has been developed for in-mine roof using measured roof drilling parameters and implemented in MRGIS (Mine Roof Geology Information System), a software package developed to allow mine engineers to make use of the large amount of roof drilling parameters for predicting roof geology properties automatically. For the development of roof bolting criteria, finite element models were developed for tensioned and fully grouted bolting

  18. The Girl on the Roof

    Institute of Scientific and Technical Information of China (English)

    刘晓宁; 邓彬

    2003-01-01

    One day when the sun was shin-ning and Jillian's office at the BBCwas getting warm,she had one of her ideas."I'll go up ontothe roof after lunch,"she thought,"andsunbathe(日光浴).I've been working hard

  19. 公共游憩型屋顶花园设计解析*--以日本琦玉广场屋顶花园为例%Design Analysis of Recreational Public Green Roof--Case Study of Saitama Plaza in Japan

    Institute of Scientific and Technical Information of China (English)

    钱万惠; 唐洪辉; 赵庆

    2016-01-01

    公共游憩型屋顶花园利用建筑“第五立面”创造生态绿色空间,是城市公共空间发展的新方向。文章通过文献资料研究及实地调查,提出了公共游憩型屋顶花园基本设计原则,以日本琦玉广场屋顶花园为具体案例,对其设计方法、建造技术与材料运用进行分析,总结出公共游憩型屋顶花园的建设必须依赖科学合理的设计、恰当的选材及先进的建造技术,三者缺一不可。%Recreational public green roof, which use the fifth elevation of building to create ecological greenspace, is a new direction for the development of urban public space. After literature review and site to visit, this paper summarized the basic design principle and used Saitama Plaza in Japan as an case study to analyse it’s designing methods and the application of techniques and materials, aiming at providing reference to the future research and design.

  20. Generating realistic roofs over a rectilinear polygon

    KAUST Repository

    Ahn, Heekap

    2011-01-01

    Given a simple rectilinear polygon P in the xy-plane, a roof over P is a terrain over P whose faces are supported by planes through edges of P that make a dihedral angle π/4 with the xy-plane. In this paper, we introduce realistic roofs by imposing a few additional constraints. We investigate the geometric and combinatorial properties of realistic roofs, and show a connection with the straight skeleton of P. We show that the maximum possible number of distinct realistic roofs over P is ( ⌊(n-4)/4⌋ (n-4)/2) when P has n vertices. We present an algorithm that enumerates a combinatorial representation of each such roof in O(1) time per roof without repetition, after O(n 4) preprocessing time. We also present an O(n 5)-time algorithm for computing a realistic roof with minimum height or volume. © 2011 Springer-Verlag.

  1. What is $\\Delta m^2_{ee}$ ?

    CERN Document Server

    Parke, Stephen

    2016-01-01

    The current short baseline reactor experiments, Daya Bay and RENO (Double Chooz) have measured (or are capable of measuring) an effective $\\Delta m^2$ associated with the atmospheric oscillation scale of 0.5 km/MeV in electron anti-neutrino disappearance. In this paper, I compare and contrast the different definitions of such an effective $\\Delta m^2$ and argue that the simple, L/E independent, definition given by $\\Delta m^2_{ee} \\equiv \\cos^2 \\theta_{12} \\Delta m^2_{31}+ \\sin^2 \\theta_{12} \\Delta m^2_{32}$, i.e. "the $\

  2. Evaluating convex roof entanglement measures.

    Science.gov (United States)

    Tóth, Géza; Moroder, Tobias; Gühne, Otfried

    2015-04-24

    We show a powerful method to compute entanglement measures based on convex roof constructions. In particular, our method is applicable to measures that, for pure states, can be written as low order polynomials of operator expectation values. We show how to compute the linear entropy of entanglement, the linear entanglement of assistance, and a bound on the dimension of the entanglement for bipartite systems. We discuss how to obtain the convex roof of the three-tangle for three-qubit states. We also show how to calculate the linear entropy of entanglement and the quantum Fisher information based on partial information or device independent information. We demonstrate the usefulness of our method by concrete examples.

  3. Green Construction in Building Renovation

    Science.gov (United States)

    Ksit, Barbara; Majcherek, Michał

    2016-06-01

    Modern materials and construction solutions draw more and more attention to ecology and building certification. Among the criteria appearing in revitalization, an important element is bringing plants back into heavily urbanized areas. In its natural form, this is not possible to carry out everywhere, often requiring large amounts of space. Nowadays, however, there are a number of green roofs and green wall systems, allowing "greener" construction without making significant changes in the urban environment. The article includes a presentation and analysis of selected solutions of biological surfaces known as green roofs and green walls, specifying various solutions and their most important features. The case study focuses primarily on material and design solutions, as well as the potential benefits, risks and limitations in their use. Plants structures on the surfaces of vertical and horizontal partitions continue to be a very interesting alternative to take into account when applying for grants, such as LEED or BREEAM certificates.

  4. Demonstration of energy savings of cool roofs

    Energy Technology Data Exchange (ETDEWEB)

    Konopacki, S.; Gartland, L.; Akbari, H. [Lawrence Berkeley National Lab., CA (United States). Environmental Energy Technologies Div.; Rainer, L. [Davis Energy Group, Davis, CA (United States)

    1998-06-01

    Dark roofs raise the summertime air-conditioning demand of buildings. For highly-absorptive roofs, the difference between the surface and ambient air temperatures can be as high as 90 F, while for highly-reflective roofs with similar insulative properties, the difference is only about 20 F. For this reason, cool roofs are effective in reducing cooling energy use. Several experiments on individual residential buildings in California and Florida show that coating roofs white reduces summertime average daily air-conditioning electricity use from 2--63%. This demonstration project was carried out to address some of the practical issues regarding the implementation of reflective roofs in a few commercial buildings. The authors monitored air-conditioning electricity use, roof surface temperature, plenum, indoor, and outdoor air temperatures, and other environmental variables in three buildings in California: two medical office buildings in Gilroy and Davis and a retail store in San Jose. Coating the roofs of these buildings with a reflective coating increased the roof albedo from an average of 0.20--0.60. The roof surface temperature on hot sunny summer afternoons fell from 175 F--120 F after the coating was applied. Summertime average daily air-conditioning electricity use was reduced by 18% (6.3 kWh/1000ft{sup 2}) in the Davis building, 13% (3.6 kWh/1000ft{sup 2}) in the Gilroy building, and 2% (0.4 kWh/1000ft{sup 2}) in the San Jose store. In each building, a kiosk was installed to display information from the project in order to educate and inform the general public about the environmental and energy-saving benefits of cool roofs. They were designed to explain cool-roof coating theory and to display real-time measurements of weather conditions, roof surface temperature, and air-conditioning electricity use. 55 figs., 15 tabs.

  5. Demonstration of energy savings of cool roofs

    Energy Technology Data Exchange (ETDEWEB)

    Konopacki, S.; Gartland, L.; Akbari, H. [Lawrence Berkeley National Lab., CA (United States). Environmental Energy Technologies Div.; Rainer, L. [Davis Energy Group, Davis, CA (United States)

    1998-06-01

    Dark roofs raise the summertime air-conditioning demand of buildings. For highly-absorptive roofs, the difference between the surface and ambient air temperatures can be as high as 90 F, while for highly-reflective roofs with similar insulative properties, the difference is only about 20 F. For this reason, cool roofs are effective in reducing cooling energy use. Several experiments on individual residential buildings in California and Florida show that coating roofs white reduces summertime average daily air-conditioning electricity use from 2--63%. This demonstration project was carried out to address some of the practical issues regarding the implementation of reflective roofs in a few commercial buildings. The authors monitored air-conditioning electricity use, roof surface temperature, plenum, indoor, and outdoor air temperatures, and other environmental variables in three buildings in California: two medical office buildings in Gilroy and Davis and a retail store in San Jose. Coating the roofs of these buildings with a reflective coating increased the roof albedo from an average of 0.20--0.60. The roof surface temperature on hot sunny summer afternoons fell from 175 F--120 F after the coating was applied. Summertime average daily air-conditioning electricity use was reduced by 18% (6.3 kWh/1000ft{sup 2}) in the Davis building, 13% (3.6 kWh/1000ft{sup 2}) in the Gilroy building, and 2% (0.4 kWh/1000ft{sup 2}) in the San Jose store. In each building, a kiosk was installed to display information from the project in order to educate and inform the general public about the environmental and energy-saving benefits of cool roofs. They were designed to explain cool-roof coating theory and to display real-time measurements of weather conditions, roof surface temperature, and air-conditioning electricity use. 55 figs., 15 tabs.

  6. Roof Polishing of Optical Fibers

    Science.gov (United States)

    Dholakia, A. R.

    1985-01-01

    Bevealed tip gives optimum coupling efficiency. Abrasive tape used to grind tip of optical fiber. Grinding force depends on stiffness of optical fiber. "Roof" shape on end of optical glass fiber increases efficiency which couples laser light. End surface angle of 65 degrees with perpendicular required for optimum coupling. Since fiber and tape are light in weight and compliant, ridge defect-free, and chipping on fiber edge totally eliminated.

  7. Solar thermal roofs; Zonthermische daken

    Energy Technology Data Exchange (ETDEWEB)

    Van de Waerdt, J. [DWA installatie- en energieadvies, Bodegraven (Netherlands)

    2012-11-15

    The purpose of the brochure is to increase the effective application of solar thermal roofs. The target group includes consultants, installers, architects and contractors. Attention is paid to the design, parameters for comparison, yield simulations and experiences gained in projects [Dutch] Het doel van de brochure is het vergroten van de effectieve toepassing van zonthermische daken. Tot de doelgroep behoren installatieadviseurs, installateurs, architecten en opdrachtgevers in de bouw. Aandacht wordt besteed aan het ontwerp, parameters voor vergelijking, opbrengstsimulaties en ervaringen opgedaan in projecten.

  8. Polyurethane adhesives in flat roofs

    Directory of Open Access Journals (Sweden)

    Bogárová Markéta

    2017-01-01

    Full Text Available It is necessary to stabilize individual layers of flat roofs, mainly because of wind suction. Apart from anchoring and surcharge, these layers can be secured by bonding. At present gluing is an indispensable and widely used stabilization method. On our market we can found many types of adhesives, most widely used are based on polyurethane. This paper focuses on problematic about stabilization thermal insulation from expanded polystyrene to vapor barrier from bitumen. One of the main issues is to calculate the exact amount of adhesive, which is required to guarantee the resistance against wind suction. In this problematic we can not find help neither in technical data sheets provided by the manufactures. Some of these data sheets contain at least information about amount of adhesive depending on location in roof plane and building height, but they do not specify the strength of such connection. It was therefore resorted to select several representatives polyurethane adhesives and their subsequent testing on specimens simulating the flat roof segment. The paper described the test methodology and results for two types of polyurethane adhesives.

  9. Green Construction in Building Renovation

    OpenAIRE

    Ksit Barbara; Majcherek Michał

    2016-01-01

    Modern materials and construction solutions draw more and more attention to ecology and building certification. Among the criteria appearing in revitalization, an important element is bringing plants back into heavily urbanized areas. In its natural form, this is not possible to carry out everywhere, often requiring large amounts of space. Nowadays, however, there are a number of green roofs and green wall systems, allowing “greener” construction without making significant changes in the urba...

  10. Green Construction in Building Renovation

    Directory of Open Access Journals (Sweden)

    Ksit Barbara

    2016-06-01

    Full Text Available Modern materials and construction solutions draw more and more attention to ecology and building certification. Among the criteria appearing in revitalization, an important element is bringing plants back into heavily urbanized areas. In its natural form, this is not possible to carry out everywhere, often requiring large amounts of space. Nowadays, however, there are a number of green roofs and green wall systems, allowing “greener” construction without making significant changes in the urban environment.

  11. OPTIMISATION OF RESIDENTIAL ROOF INSULATION LAYER THICKNESS BASED ON ECONOMIC ANALYSIS BY GREY RELATION METHOD

    Directory of Open Access Journals (Sweden)

    D. PRAKASH

    2015-12-01

    Full Text Available This study is focussed on the optimisation of residential building roof insulation layers that includes weathering tile, wood wool and phase change material through grey relation analysis and numerical simulation techniques. The optimum thickness of insulation layers is determined for the quality objective of minimization of insulation material cost and energy consumption cost by air conditioning system over a life time of 10 years. For optimisation of roof insulation layer, the insulation layers are varied to five levels with reference to the height of concrete (HC layer and various combination of roof layers are obtained from Taguchi’s L25 orthogonal array. The 25 combination of roof structures are analysed by Numerical simulation technique to determine yearly heating transmission load and in turn used to calculate the cost of energy consumption for cooling a period of 10 years. As a result, the optimum thickness value of roof insulation layer - weathering tile, wood wool and phase change material are predicted as 0.33*HC, 0.33*HC and 0.066*HC respectively and this optimum value will have the cost of insulation and yearly electricity cost of cooling for 10 years as 92 $/m2 and 12.45$/m2 respectively.

  12. M2M massive wireless access

    DEFF Research Database (Denmark)

    Zanella, Andrea; Zorzi, Michele; Santos, André F.

    2013-01-01

    of the current cellular standards. Here, we provide insights and introduce potential solutions for the cellular radio protocol that will allow the efficient support of Machine-to-Machine (M2M) communications. The paper focuses on the massive aspect of M2M. We will introduce PHY and MAC approaches such as Coded...... and research guidelines for enabling future networks to support efficiently M2M communications....

  13. Fire safety challenges of green buildings

    CERN Document Server

    Meacham, Brian; Echeverria, Juan; Cheng, Raymond

    2013-01-01

    Environmental concerns and advances in architectural technologies have lead to a greater number of green buildings or buildings with green, eco-friendly elements. However, from a practical standpoint, there is no incident reporting system in the world that tracks data on fire incidents in green buildings. Fire safety objectives are not explicitly considered in most green rating schemes, and green design features have been associated with photovoltaic panels and roof materials, lightweight timber frame buildings, and combustible insulation materials. Fire Safety Challenges of Green Buildings is

  14. Green walls in Vancouver

    Energy Technology Data Exchange (ETDEWEB)

    Sharp, R. [Sharp and Diamond Landscape Architecture Inc., Vancouver, BC (Canada)

    2007-07-01

    With the renewed interest in design for microclimate control and energy conservation, many cities are implementing clean air initiatives and sustainable planning policies to mitigate the effects of urban climate and the urban heat island effect. Green roofs, sky courts and green walls must be thoughtfully designed to withstand severe conditions such as moisture stress, extremes in temperature, tropical storms and strong desiccating winds. This paper focused on the installation of green wall systems. There are 2 general types of green walls systems, namely facade greening and living walls. Green facades are trellis systems where climbing plants can grow vertically without attaching to the surface of the building. Living walls are part of a building envelope system where plants are actually planted and grown in a wall system. A modular G-SKY Green Wall Panel was installed at the Aquaquest Learning Centre at the Vancouver Aquarium in Stanley Park in September 2006. This green wall panel, which was originally developed in Japan, incorporates many innovative features in the building envelope. It provides an exterior wall covered with 8 species of plants native to the Coastal Temperate Rain Forest. The living wall is irrigated by rainwater collected from the roof, stored in an underground cistern and fed through a drip irrigation system. From a habitat perspective, the building imitates an escarpment. Installation, support systems, irrigation, replacement of modules and maintenance are included in the complete wall system. Living walls reduce the surface temperature of buildings by as much as 10 degrees C when covered with vegetation and a growing medium. The project team is anticipating LEED gold certification under the United States-Canada Green Building Council. It was concluded that this technology of vegetated building envelopes is applicable for acoustical control at airports, biofiltration of indoor air, greywater treatment, and urban agriculture and vertical

  15. 非充分灌溉对屋顶绿化大叶黄杨生长及水碳通量的影响%Effects of deficit irrigation on growth, water and carbon fluxes of Euonymus japonicas for green roof

    Institute of Scientific and Technical Information of China (English)

    王材源; 杨培岭; 李云开; 任树梅; 路璐; 赵鲁

    2012-01-01

    北京市绿地大面积发展,加剧了水资源和可用于绿化的土地资源短缺的紧张局面,为此,实施屋顶绿化对缓解北京市资源与能源紧缺的严重局面有重要意义.该文以典型的屋项绿化植物大叶黄杨为研究对象,采用盆栽试验,研究在充分灌溉(CK) (90%~100%FC)、低度水分胁迫(LWS) (75%~85%FC)、中度水分胁迫(MWS) (65%~75%FC)、高度水分胁迫(SWS) (50%~60%FC)4种不同土壤水分控制水平下,大叶黄杨的生理响应、景观功能及生态服务功能.研究发现,大叶黄杨的光合速率、蒸腾速率、气孔导度及水分利用效率在水分胁迫的三个处理中LWS>MWS>SWS,LWS处理与CK处理相比,光合速率、蒸腾速率、气孔导度及水分利用效率仅相差1.55%、3.3%、4.13%、7.1%,叶面积大7.8%,叶绿素含量高3.1%;在生态服务功能方面,固碳释氧与降温增湿量在不同水分条件下相差并不明显.低度水分胁迫(LWS) (75%~85%FC)刺激了大叶黄杨的生长,有效地调节了同化物在叶片生长及叶绿素上的分配,同时在生态环境上发挥了巨大作用,是一种切实可行的节水灌溉模式.%To solve the contradiction between the development of large areas of urban Greenland and scarcity of land and water resources for Greenland in Beijing, the implementation of green-roof vegetation is important. In this paper, the typical green-roof plant (E.japonicus) as the research object, the physiological response, landscape function and ecological serves function of E.japonicus were analyzed with the pot experiments in 4 different treatments of full irrigation (CK) (90%-100%FC), low water stress (LWS) (75%-85%FC), moderate water stress (MWS) (65%-75%FC), and serious water stress (SWS) (50%-60%FC) treatments. The results showed that the photosynthetic rate, transpiration rate, stomatal conductance and water use efBciency of E.japonicus was LWS>MWS>SWS respectively in three

  16. Realistic roofs over a rectilinear polygon

    KAUST Repository

    Ahn, Heekap

    2013-11-01

    Given a simple rectilinear polygon P in the xy-plane, a roof over P is a terrain over P whose faces are supported by planes through edges of P that make a dihedral angle π/4 with the xy-plane. According to this definition, some roofs may have faces isolated from the boundary of P or even local minima, which are undesirable for several practical reasons. In this paper, we introduce realistic roofs by imposing a few additional constraints. We investigate the geometric and combinatorial properties of realistic roofs and show that the straight skeleton induces a realistic roof with maximum height and volume. We also show that the maximum possible number of distinct realistic roofs over P is ((n-4)(n-4)/4 /2⌋) when P has n vertices. We present an algorithm that enumerates a combinatorial representation of each such roof in O(1) time per roof without repetition, after O(n4) preprocessing time. We also present an O(n5)-time algorithm for computing a realistic roof with minimum height or volume. © 2013 Elsevier B.V.

  17. Orbital dystopia due to orbital roof defect.

    Science.gov (United States)

    Rha, Eun Young; Joo, Hong Sil; Byeon, Jun Hee

    2013-01-01

    We performed a retrospective review of patients who presented with delayed dystopia as a consequence of an orbital roof defect due to fractures and nontraumatic causes to search for a correlation between orbital roof defect size and surgical indications for the treatment thereof. Retrospective analyses were performed in 7 patients, all of whom presented with delayed dystopia due to orbital roof defects, between January 2001 and June 2011. The causes of o