scholarly journals A Roof of Greenery, but a Sky of Unexplored Relations—Meta-Analysis of Factors and Properties That Affect Green Roof Hydrological and Thermal Performances

2021 ◽  
Vol 13 (18) ◽  
pp. 10017
Author(s):  
Mithun Hanumesh ◽  
Rémy Claverie ◽  
Geoffroy Séré
Keyword(s):  
Urban Areas ◽  
Meta Analysis ◽  
Green Roof ◽  
Environmental Issues ◽  
Green Roofs ◽  
Positive Influence ◽  
External Factors ◽  
Experimental Approaches ◽  
Internal Properties ◽  
Work First

Green roofs are expected to contribute to the mitigation of multiple environmental issues that affect urban areas. Owing to their composition, organization, and external factors, the performances of green roofs have been demonstrated to be overall positive but strongly variable. Our work first aims at proposing consensual definitions and a frame adapted to these biotic-abiotic systems. It also aims at shedding light on the qualitative relations between various internal properties and external factors of green roofs on their hydrological and thermal performances. One hundred relevant study papers were filtered from 395 papers as per our defined search criteria based on originality and precision. The expectations were to be capable of hierarchizing factors and properties that would influence the performances of green roofs. The main findings highlighted that most factors and properties have a positive influence on the performances of green roofs, showing there are many existing levers to enhance the green roof performances and tackle some of the main urban environmental issues. However, even if previous research has already explored various relations, in the final filtered consideration of 6 performances and 30 factors and properties, there was a possibility of 180 combined factor–property–performance relations studies overall. Out of these possibilities, only 82 have been studied at least once, leaving the other 98 relations (54%) unexplored. Considering that these lists were far from exhaustive, a huge potential in determining green roof performances remains unearthed. In this regard, various proposals have been made regarding: (i) identification of levers to enhance the performances of green roofs; (ii) filling the gaps: the exploration of the unstudied relations; (iii) promotion of deeper and innovative experimental approaches for research on green roof performances; and (iv) the shift from mono to transdisciplinary research about green roofs.

INVESTIGATING THE ENVIRONMENTAL IMPACTS OF GREEN ROOF INSTALLATION

2015 ◽  
Vol 76 (1) ◽  
Author(s):  
Amir Mahdiyar ◽  
Arham Abdullah ◽  
Sanaz Tabatabaee ◽  
Leily Mahdiyar ◽  
Saeed Reza Mohandes
Keyword(s):  
Urban Areas ◽  
Green Roof ◽  
Environmental Issues ◽  
Green Roofs ◽  
Developed Countries ◽  
Economic Benefits ◽  
Environmental Benefits ◽  
Adverse Impacts ◽  
Increasing Trend ◽  
Rural Places

Green roof installation has been used as a sustainable approach for many years in order to reduce the adverse impacts of environmental issues all around the world. These environmental issues include: global warming, air pollution, flood, carbon footprint and so on. Green roofs are practical as a sustainable approach, especially in developed countries; however, there is an increasing trend of implementing green roofs in developing countries. This paper is reviewing the benefits of green roof installation and how green roof might contribute to reduce the negative environmental issues. The environmental problems that can be solved or reduced by these benefits are discussed separately in this paper. It is concluded that due to the environmental benefits of green roof installation, it leads to many economic benefits. Moreover, green roof implementation is beneficial in both urban areas and rural places.

scholarly journals Addressing the Water–Energy–Food Nexus through Enhanced Green Roof Performance

2021 ◽  
Vol 13 (4) ◽  
pp. 1972
Author(s):  
Jeremy Wright ◽  
Jeremy Lytle ◽  
Devon Santillo ◽  
Luzalen Marcos ◽  
Kristiina Valter Mai
Keyword(s):  
Climate Change ◽  
Performance Optimization ◽  
Urban Areas ◽  
Stormwater Management ◽  
Green Roof ◽  
Green Roofs ◽  
Management Tool ◽  
Contributing Factors ◽  
Rainwater Runoff ◽  
Rain Events

Urban densification and climate change are creating a multitude of issues for cities around the globe. Contributing factors include increased impervious surfaces that result in poor stormwater management, rising urban temperatures, poor air quality, and a lack of available green space. In the context of volatile weather, there are growing concerns regarding the effects of increased intense rainfalls and how they affect highly populated areas. Green roofs are becoming a stormwater management tool, occupying a growing area of urban roof space in many developed cities. In addition to the water-centric approach to the implementation of green roofs, these systems offer a multitude of benefits across the urban water–energy–food nexus. This paper provides insight to green roof systems available that can be utilized as tools to mitigate the effects of climate change in urbanized areas. A new array of green roof testing modules is presented along with research methods employed to address current issues related to food, energy and water performance optimization. Rainwater runoff after three rain events was observed to be reduced commensurate with the presence of a blue roof retention membrane in the testbed, the growing media depth and type, as well as the productive nature of the plants in the testbed. Preliminary observations indicate that more productive green roof systems may have increasingly positive benefits across the water–energy–food nexus in dense urban areas that are vulnerable to climate disruption.

scholarly journals Evaporation from (Blue-)Green Roofs: Assessing the Benefits of a Storage and Capillary Irrigation System Based on Measurements and Modeling

Water ◽  
2018 ◽  
Vol 10 (9) ◽  
pp. 1253 ◽  
Author(s):  
Dirk Cirkel ◽  
Bernard Voortman ◽  
Thijs van Veen ◽  
Ruud Bartholomeus
Keyword(s):  
Energy Balance ◽  
Urban Areas ◽  
Evaporation Rate ◽  
Climate Adaptation ◽  
Irrigation System ◽  
Green Roof ◽  
Green Roofs ◽  
C3 Plants ◽  
Rapid Decline ◽  
Air Temperatures

Worldwide cities are facing increasing temperatures due to climate change and increasing urban density. Green roofs are promoted as a climate adaptation measure to lower air temperatures and improve comfort in urban areas, especially during intensive dry and warm spells. However, there is much debate on the effectiveness of this measure, because of a lack of fundamental knowledge about evaporation from different green roof systems. In this study, we investigate the water and energy balance of different roof types on a rooftop in Amsterdam, the Netherlands. Based on lysimeter measurements and modeling, we compared the water and energy balance of a conventional green roof with blue-green roofs equipped with a novel storage and capillary irrigation system. The roofs were covered either with Sedum or by grasses and herbs. Our measurements and modeling showed that conventional green roof systems (i.e., a Sedum cover and a few centimeters of substrate) have a low evaporation rate and due to a rapid decline in available moisture, a minor cooling effect. Roofs equipped with a storage and capillary irrigation system showed a remarkably large evaporation rate for Sedum species behaving as C3 plants during hot, dry periods. Covered with grasses and herbs, the evaporation rate was even larger. Precipitation storage and capillary irrigation strongly reduced the number of days with dry-out events. Implementing these systems therefore could lead to better cooling efficiencies in cities.

scholarly journals Vegetation Cover Drives Arthropod Communities in Mediterranean/Subtropical Green Roof Habitats

2018 ◽  
Vol 10 (11) ◽  
pp. 4209 ◽  
Author(s):  
Ibrahim Salman ◽  
Leon Blaustein
Keyword(s):  
Vegetation Cover ◽  
Urban Areas ◽  
Green Roof ◽  
Structural Complexity ◽  
Green Roofs ◽  
Life Forms ◽  
Suitable Habitat ◽  
Positive Effects ◽  
Habitat Template ◽  
Arthropod Abundance

Worldwide, urban areas are expanding both in size and number, which results in a decline in habitats suitable for urban flora and fauna. The construction of urban green features, such as green roofs, may provide suitable habitat patches for many species in urban areas. On green roofs, two approaches have been used to select plants—i.e., matching similar habitat to green roofs (habitat template approach) or identifying plants with suitable traits (plant trait approach). While both approaches may result in suitable habitats for arthropods, how arthropods respond to different combinations of plants is an open question. The aim of this study was to investigate how the structural complexity of different plant forms can affect the abundance and richness of arthropods on green roofs. The experimental design crossed the presence and absence of annuals with three Sedum sediforme (Jacq.) Pau (common name: stonecrops) treatments—i.e., uniformly disrupted Sedum, clumped disrupted Sedum, and no Sedum. We hypothesized that an increased structural diversity due to the coexistence of different life forms of plants on roofs is positively related to the abundance and richness of arthropods. We found that arthropod abundance and richness were positively associated with the percent of vegetation cover and negatively associated with substrate temperature. Neither arthropod abundance nor richness was influenced by the relative moisture of substrate. We also found that arthropod abundance and richness varied by green roof setups (treatments) and by seasonality. Arthropod abundance on green roofs was the highest in treatments with annuals only, while species richness was slightly similar between treatments containing annuals but varied between sampling periods. This study suggests that adding annuals to traditional Sedum roofs has positive effects on arthropods. This finding can support the development of biodiverse cities because most extensive green roofs are inaccessible to the public and can provide undisturbed habitat for several plant and arthropod species.

scholarly journals IMPACT OF GREEN ROOF ON HEATING AND COOLING IN CONTEXT OF DIFFERENT CLIMATIC ZONES IN INDIA

2021 ◽  
pp. 436-440
Author(s):  
Ar. Ankur Bhardwaj ◽  
Dr. Shweta Chaudhary ◽  
Ar.Kirti Varandani
Keyword(s):  
Urban Areas ◽  
Green Roof ◽  
Green Roofs ◽  
Climatic Zones ◽  
Sustainable Living ◽  
Secondary Sources ◽  
Heating And Cooling ◽  
The World ◽  
Depth Study ◽  
Rainwater Runoff

The ecological, social and visual commitments that green roofs can make towards sustainable living in more intensified urban centres are generally recognized around the world. Green roof is one such sustainable methodology, utilization of which causes us in insulating the buildings and, subsequently contributing to better energy proficient execution of the same. Green roofs additionally give environment to various species, lessen the rainwater runoff and better deal with the carbon-dioxide cycle. In spite of these advantages, Green roofs are not as basic an element in India as they are in other European and American urban areas. In this paper an attempt has been made to enhance the advantages of this innovation in India. Green roofs systems looks simple in terms of setting up, but actually very complex in maintaining and achieving sustainability. In depth study of green roofs, historic background, climatic zones, impacts of green roofs on heating and cooling, benefits, problems and opportunities is done with the help of data taken from secondary sources like books, magazines and published literature (articles, journals, conference proceedings) form various e-libraries and other online platforms. KEY WORDS: Heating, Cooling, Green Roof, Sustainability)

scholarly journals Surface temperature analysis of conventional roof and different use forms of the green roof

2019 ◽  
Vol 28 (4) ◽  
pp. 632-640
Author(s):  
Anna Baryła ◽  
Agnieszka Bus ◽  
Agnieszka Karczmarczyk ◽  
Joanna Witkowska-Dobrev
Keyword(s):  
Green Infrastructure ◽  
Urban Areas ◽  
Imaging System ◽  
Plant Cover ◽  
Effective Means ◽  
Green Roof ◽  
Green Roofs ◽  
Temperature Changes ◽  
Urban Heat ◽  
Thermal Imaging System

Increasing urban populations raises a number of problems and risks that are strengthened by observed and projected climate change. An increase in green areas (so-called green infrastructure) has turned out to be an effective means of lowering temperature in the city. Green roofs can be one of the possible measures leading to achieving this aim. The aim of the study was the analysis of temperature changes of different roof surfaces (conventional roof, board, intensive roof substrate without plant cover, substrate covered with plants (shrubs). Studies on comparing the temperature between a conventional roof and green roofs were carried out in the period from April to September 2015 on the roof of the building of the Faculty of Modern Languages, University of Warsaw. The measurement was performed using the FLIR SC620 thermal imaging system. As a result of the tests, it was found that in the summer months the differences between the temperature of the green roof and the conventional roof amounted to a maximum of 31.3°C. The obtained results showed that the roof with vegetation can signifi cantly contribute to the mitigation of the urban heat island phenomenon in urban areas during summer periods.

scholarly journals A review of green roof incentives as motivators for the expansion of green infrastructure in European cities

2019 ◽  
Vol 28 (4) ◽  
pp. 641-652 ◽  
Author(s):  
Ewa Burszta-Adamiak ◽  
Wiesław Fiałkiewicz
Keyword(s):  
Green Infrastructure ◽  
Urban Areas ◽  
Financial Incentives ◽  
Large Scale ◽  
Green Roof ◽  
Green Roofs ◽  
Negative Effects ◽  
European Cities

Nowadays green roofs play a key role in alleviating the negative effects of urbanization. Despite investors awareness of the advantages of green roofs, there are still some barriers that hinder investments on a large scale. As a result a financial and non-financial incentives are implemented. The review presented in this paper allowed to identify the most popular initiatives and to formulate recommendations for creating incentive supporting implementation of green roofs in urban areas.

The effect of drainage height on plant-species composition on a semi-arid green roof system

2021 ◽  
Vol 67 (3-4) ◽  
pp. 149-155
Author(s):  
Har'el Agra ◽  
Hadar Shalom ◽  
Omar Bawab ◽  
Gyongyver J. Kadas ◽  
Leon Blaustein
Keyword(s):  
Species Composition ◽  
Plant Species ◽  
Plant Diversity ◽  
Urban Areas ◽  
Green Roof ◽  
Growing Season ◽  
Green Roofs ◽  
Plant Species Composition ◽  
Roof System ◽  
Semi Arid

Abstract Green roofs are expected to contribute to higher biodiversity in urban surroundings. Typically, green roofs have been designed with low plant diversity. However, plant diversity can be enhanced by controlling resource availability and creating distinct niches. Here we hypothesize that by using different drainage heights during the short plant-growing season in a semi-arid green roof system we can create distinct niches and plant communities. Our experiment took place at the University of Haifa, north Israel. We tested three different heights of drainage outlet: 10 cm under the surface of the substrate (Low), 1 cm under the surface of the substrate (Medium) and 3 cm above the surface of the substrate (High) on plant species-composition in green-roof gardens. Grasses cover was higher in High and Medium drainages while forbs cover was higher in Low drainage. Species richness was the highest in Low drainage while diversity indices showed the opposite trend. We conclude that by changing the height of the drainage we can create different niches and change species composition in a short time period of one growing season. This way we can create more diverse green roof communities and enhance biodiversity in urban areas, particularly in semi-arid regions.

The Potential of Recycled Locally-Sourced Waste Materials for Green Roof Soil Mixtures

2017 ◽  
Vol 730 ◽  
pp. 445-451
Author(s):  
Hartini Kasmin ◽  
Siti Nur Ummiah Munir ◽  
Nur Syafira Razak ◽  
Nor Azizi Yusoff ◽  
Rosniza Kassim ◽  
...  
Keyword(s):  
Urban Areas ◽  
Climatic Factors ◽  
Green Roof ◽  
Water Storage ◽  
Green Roofs ◽  
Waste Materials ◽  
Peat Moss ◽  
Water Runoff ◽  
Maximum Water ◽  
Soil Mixtures

The increase in surface runoff has become a serious environmental problem and concern in Malaysia. Hence, promoting the use of green roofs in urban areas will potentially allow some storage area and time attenuation for any rainfall. Initial studies on a few substrate mixtures were done in order to find out the properties of green roof media. These included vermiculite (V), perlite (P) and peat moss (PM) together with locally-sourced waste materials such as empty fruit bunches (EFB) and wet diaper gel (D) which are expected to potentially retain more storm water runoff. A test on the substrate mixture properties and evaporation tests were conducted on seven types of soil mixtures. The results show that a basic substrate mixture of PVPM3,5,2 has a maximum water capacity of 50%. The modification and addition of diaper gel in DVPM1,3,2 and empty fruit bunch (EFB) in PEFBPM1,0.3,2 show an increment in both mixtures’ water holding capacity (54%). All the proposed mixtures have shown permeability values larger than 0.0005 cm/s. To investigate the maximum water storage availability, the evaporation tests show that both mixtures could provide 60 - 62 mm of water storage after 34 days without rainfall under ambient climatic condition (32 ̊ to 34 ̊) whereas under extreme heat temperatures (50 ̊), both mixtures took only 1 day to provide the same storage as the ambient condition. Therefore, this study has provided an initial understanding of the properties of the substrate mixture as well as the evaporation rate of the materials tested. This information can be used to demonstrate the relationship between soil characteristics and local climatic factors (temperature).

scholarly journals Model research on the influence of green roofs on environmental parameters in urban agglomerations

2018 ◽  
Vol 45 ◽  
pp. 00094 ◽  
Author(s):  
Dariusz Suszanowicz
Keyword(s):  
Heavy Metals ◽  
Urban Areas ◽  
Air Pollutants ◽  
Green Roof ◽  
Soil Layer ◽  
Environmental Parameters ◽  
Green Roofs ◽  
Field Studies ◽  
Air Pollutant ◽  
Laboratory Scale

This study presents features of green roofs in urban areas with a particular emphasis on the filtration of air pollutants, heavy metals removal, reduction of rainwater runoff from roof surfaces and thermal insulation. To carry out field studies on the influence of green roofs on the environment in urban areas, two green roof models on a laboratory scale were used. The observations of the prepared green roof models made during the summer, autumn and winter confirmed the extremely beneficial effect of this type of roof for the elimination of air pollutant, heavy metals, and particulate matter. The observations also confirmed that plants on a green roof growing on a soil layer absorb an average of 74% of rain water and then allow it to evaporate. The selection of plants for green roofs should mainly focus on how effectively they improve urban environmental parameters and remove air pollutants. The results of the study of the two green roof models on a laboratory scale are necessary to work out the parameters of layers of the roof and select the most appropriate plants for the reference research object on the roof of one of buildings of the University of Opole.

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