scholarly journals Effect of Substrate Depth and Planting Season on Sedum Plug Survival on Green Roofs

2007 ◽  
Vol 25 (2) ◽  
pp. 95-99 ◽  
Author(s):  
Kristin L. Getter ◽  
D. Bradley Rowe
Keyword(s):  
Survival Rates ◽  
Green Roofs ◽  
Heat Island ◽  
Major Objective ◽  
Island Effect ◽  
Successful Establishment ◽  
Urban Heat ◽  
Growing Conditions ◽  
Substrate Depth ◽  
Planting Season

Abstract Green roofs, a roofing technology that entails growing plants on rooftops, provide many benefits such as improved stormwater management, energy conservation, mitigation of the urban heat island effect, increased longevity of roofing membranes, reduction in noise and air pollution, and improved aesthetics. Plants on rooftops are more susceptible to extremes in temperature and drought due to their shallow substrate and elevation above ground. Because of these unfavorable growing conditions, plant selection and season of establishment are critical. The major objective of this study was to quantify the effect of substrate depth and planting season on successful establishment of plugs of Sedum species on green roofs. Plugs of nine species of Sedum were planted in East Lansing, MI, in autumn (September 20, 2004) or spring (June 8, 2005) and then evaluated for survival on June 1, 2005, and June 1, 2006, respectively. Overall, spring planting exhibited superior survival rates (81%) compared to autumn (23%) across substrate depths. Sedum cauticola ‘Lidakense’, S. floriferum, and S. sexangulare were not affected by season of planting. Sedum cauticola barely survived at any substrate depth or planting season, whereas the latter two exhibited nearly 100% survival regardless of planting season. All other species had superior survival percentages when planted during spring.

scholarly journals Evidence of the Climate Mitigation Effect of Green Roofs—A 20-Year Weather Study on an Extensive Green Roof (EGR) in Northeast Germany

Buildings ◽  
2019 ◽  
Vol 9 (7) ◽  
pp. 157 ◽  
Author(s):  
Manfred Köhler ◽  
Daniel Kaiser
Keyword(s):  
Urban Heat Island ◽  
Green Roof ◽  
Green Roofs ◽  
Good News ◽  
Urban Heat Island Effect ◽  
Climate Mitigation ◽  
Heat Island ◽  
Case Scenario ◽  
Island Effect ◽  
Urban Heat

Approximately 10 km2 of new green roofs are built in Germany every year. About 85% of these are Extensive Green Roofs (EGR). An EGR with several research features was installed on new buildings belonging to the University of Applied Sciences Neubrandenburg in 1999. The results of the almost 20-year permanent survey of the climate effects of the green roof in contrast to gravel roofs are presented here. High-quality sensors, similar to those used by official weather stations, are in use, and data is collected every 10 s and aggregated to hourly values which enable comparisons to official measurements made by the DWD in Neubrandenburg and Berlin. The results show the typical urban heat island effect (UHI) and the mitigation effect of EGR. Whilst the temperature increased over the years due to the urban heat island effect, the temperature within the growing media in the green roof remained constant. The EGR has a stabilization effect of 1.5 K. This is good news for all those seeking a UHI mitigation solution for city centers. In a best-case scenario, the green roof potential of cities in Germany is between 3 and 8%. A value of 50% can be achieved for all buildings; roofs represent about ¼ of urban surfaces, and the cooling effect of 1.5 K in 20 years is a reasonable contribution to cooling cities and achieving environmental goals by greening urban surfaces.

The Thermal Influence of Green Roofs on Air Temperature in Taipei City

2010 ◽  
Vol 44-47 ◽  
pp. 1933-1937 ◽  
Author(s):  
Chen Yi Sun
Keyword(s):  
Air Temperature ◽  
Thermal Environment ◽  
Green Roof ◽  
Green Roofs ◽  
Heat Island ◽  
Environmental Benefit ◽  
Island Effect ◽  
Taipei City ◽  
Urban Heat ◽  
Thermal Influence

During the last decade, a large amount of research has been published in Taiwan on the reduction of the urban heat island effect for different strategies. The most important strategy for reducing ambient temperature and mitigating the heat island effect is to encourage citizens to build green roofs on their buildings. For analyzing the effect of a green roof on the thermal environment, this paper collects temperature and humidity data from two building roofs that have different greening levels and tries to analyze the thermal influence of a green roof on air temperature in Taipei City. The results of this research can give citizens an idea what kind of thermal environment they can benefit from; moreover, it also can provide useful data to governments for calculating the environmental benefit if they carry out a green roof policy.

scholarly journals Detecting the Cool Island Effect of Urban Parks in Wuhan: A City on Rivers

2020 ◽  
Vol 18 (1) ◽  
pp. 132
Author(s):  
Qijiao Xie ◽  
Jing Li
Keyword(s):  
Remote Sensing ◽  
Negative Impact ◽  
Remote Sensing Data ◽  
Urban Parks ◽  
High Water ◽  
Water Bodies ◽  
Green Spaces ◽  
Heat Island ◽  
Island Effect ◽  
Urban Heat

As a nature-based solution, development of urban blue-green spaces is widely accepted for mitigating the urban heat island (UHI) effect. It is of great significance to determine the main driving factors of the park cool island (PCI) effect for optimizing park layout and achieving a maximum cooling benefit of urban parks. However, there have been obviously controversial conclusions in previous studies due to varied case contexts. This study was conducted in Wuhan, a city with high water coverage, which has significant differences in context with the previous case cities. The PCI intensity and its correlation with park characteristics were investigated based on remote sensing data. The results indicated that 36 out of 40 urban parks expressed a PCI effect, with a PCI intensity of 0.08~7.29 °C. As expected, larger parks with enough width had stronger PCI intensity. An increased density of hardened elements in a park could significantly weaken PCI effect. Noticeably, in this study, water bodies in a park contributed the most to the PCI effect of urban parks, while the vegetated areas showed a negative impact on the PCI intensity. It implied that in a context with higher water coverage, the cooling effect of vegetation was weakened or even masked by water bodies, due to the interaction effect of different variables on PCI intensity.

scholarly journals Cooling Effect of Different Land Cover Types: A Case Study in Xi’an and Xianyang, China

2021 ◽  
Vol 13 (3) ◽  
pp. 1099
Author(s):  
Yuhe Ma ◽  
Mudan Zhao ◽  
Jianbo Li ◽  
Jian Wang ◽  
Lifa Hu
Keyword(s):  
Land Cover ◽  
Surface Temperature ◽  
Urban Heat Island ◽  
Land Surface Temperature ◽  
Land Surface ◽  
Cooling Effect ◽  
Heat Island ◽  
Land Cover Types ◽  
Island Effect ◽  
Urban Heat

One of the climate problems caused by rapid urbanization is the urban heat island effect, which directly threatens the human survival environment. In general, some land cover types, such as vegetation and water, are generally considered to alleviate the urban heat island effect, because these landscapes can significantly reduce the temperature of the surrounding environment, known as the cold island effect. However, this phenomenon varies over different geographical locations, climates, and other environmental factors. Therefore, how to reasonably configure these land cover types with the cooling effect from the perspective of urban planning is a great challenge, and it is necessary to find the regularity of this effect by designing experiments in more cities. In this study, land cover (LC) classification and land surface temperature (LST) of Xi’an, Xianyang and its surrounding areas were obtained by Landsat-8 images. The land types with cooling effect were identified and their ideal configuration was discussed through grid analysis, distance analysis, landscape index analysis and correlation analysis. The results showed that an obvious cooling effect occurred in both woodland and water at different spatial scales. The cooling distance of woodland is 330 m, much more than that of water (180 m), but the land surface temperature around water decreased more than that around the woodland within the cooling distance. In the specific urban planning cases, woodland can be designed with a complex shape, high tree planting density and large planting areas while water bodies with large patch areas to cool the densely built-up areas. The results of this study have utility for researchers, urban planners and urban designers seeking how to efficiently and reasonably rearrange landscapes with cooling effect and in urban land design, which is of great significance to improve urban heat island problem.

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