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

2017 ◽  
Vol 76 (5) ◽  
pp. 1081-1089 ◽  
Author(s):  
Cristina M. Monteiro ◽  
Cristina S. C. Calheiros ◽  
Paulo Palha ◽  
Paula M. L. Castro
Keyword(s):  
Organic Matter ◽  
Plant Species ◽  
Urban Areas ◽  
Mediterranean Climate ◽  
Green Roof ◽  
Oxygen Demand ◽  
Green Roofs ◽  
Water Runoff ◽  
Aromatic Plant ◽  
Runoff Quality

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−, PO43- 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.

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

2016 ◽  
Vol 73 (8) ◽  
pp. 1842-1847 ◽  
Author(s):  
Cristina M. Monteiro ◽  
Cristina S. C. Calheiros ◽  
Carla Pimentel-Rodrigues ◽  
Armando Silva-Afonso ◽  
Paula M. L. Castro
Keyword(s):  
Urban Areas ◽  
Mediterranean Climate ◽  
Rainwater Harvesting ◽  
Oxygen Demand ◽  
Green Roofs ◽  
Atmospheric Pollutants ◽  
Water Runoff ◽  
Mediterranean Countries ◽  
Harvesting Systems ◽  
Monthly Runoff

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−, PO43−, 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.

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

2013 ◽  
Vol 68 (6) ◽  
pp. 1419-1424 ◽  
Author(s):  
Ilaria Gnecco ◽  
Anna Palla ◽  
Luca G. Lanza ◽  
Paolo La Barbera
Keyword(s):  
Atmospheric Deposition ◽  
Water Chemistry ◽  
Mediterranean Climate ◽  
Green Roof ◽  
Green Roofs ◽  
Storm Water ◽  
Water Runoff ◽  
Experimental Site ◽  
Storm Water Runoff ◽  
Runoff Quality

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.

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 Developing an evaluation tool for green roof typologies

2021 ◽  
Author(s):  
Cameron Laidlaw
Keyword(s):  
Urban Environment ◽  
Green Roof ◽  
Green Roofs ◽  
Water Runoff ◽  
Evaluation Tool ◽  
Quality Maintenance ◽  
The Future ◽  
Criteria For Evaluation ◽  
Specific Project ◽  
Runoff Quality

Green roofs possess the potential to provide a plethora of benefits in the urban environment. The variability among the green roof typologies (intensive, extensive, and agriculture) leads to different benefits when one system is selected over another. By the collection and analyzing of metadata, an evaluation tool is developed to assist green roof designers to meet the goals of their specific project. Included criteria for evaluation are: water runoff quantity, water runoff quality, maintenance, amenity, and irrigation. The evaluation tool is designed to be compartmentalized, with each criteria treated independently, allowing further expansion, alteration, or refinement of the tool in the future.

scholarly journals Developing an evaluation tool for green roof typologies

2021 ◽  
Author(s):  
Cameron Laidlaw
Keyword(s):  
Urban Environment ◽  
Green Roof ◽  
Green Roofs ◽  
Water Runoff ◽  
Evaluation Tool ◽  
Quality Maintenance ◽  
The Future ◽  
Criteria For Evaluation ◽  
Specific Project ◽  
Runoff Quality

Green roofs possess the potential to provide a plethora of benefits in the urban environment. The variability among the green roof typologies (intensive, extensive, and agriculture) leads to different benefits when one system is selected over another. By the collection and analyzing of metadata, an evaluation tool is developed to assist green roof designers to meet the goals of their specific project. Included criteria for evaluation are: water runoff quantity, water runoff quality, maintenance, amenity, and irrigation. The evaluation tool is designed to be compartmentalized, with each criteria treated independently, allowing further expansion, alteration, or refinement of the tool in the future.

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 A laboratory study to determine the use of polluted river sediment as a substrate for extensive green roofs

2018 ◽  
Vol 78 (11) ◽  
pp. 2247-2255 ◽  
Author(s):  
Wei Zhang ◽  
Xing Zhong ◽  
Wu Che ◽  
Huichao Sun ◽  
Hailong Zhang
Keyword(s):  
River Sediment ◽  
Peat Soil ◽  
River Sediments ◽  
Green Roof ◽  
Oxygen Demand ◽  
Green Roofs ◽  
Polluted River ◽  
Artificial Rainfall ◽  
Study Laboratory ◽  
Extensive Green Roofs

Abstract In this study, laboratory-scale green (e.g. living) roof platforms were established to assess the potential use of polluted river sediment in their substrate mixture. The mean runoff retention of the green roof platforms, which contained peat and/or river sediment, after 11 artificial rainfall events was >72%, significantly higher than traditional roofs. However, green roof platforms that had been filled with peat soil showed chemical oxygen demand (COD), total nitrogen (TN) and total phosphorus (TP) leaching. Green roofs that had used river sediment showed good leaching control for COD, TN and TP. The cumulative leaching masses from the green roofs contained 30% (COD), 42% (TN) and 47% (TP) as much as the total leaching mass from traditional roofs, and the Cu, Zn, Cd and Pb leaching risk from green roofs when river sediments are used as part of a substrate mixture was relatively low. Despite some nutrient leaching in the initial phase of runoff from the green roofs, river sediment has the potential to be used as a substrate for extensive green roofs.

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.

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