Drought Resistance Assessment of Ground Cover Plants for Low Management and Light Weight Green Roof System

A green roof is composed of a substrate and drainage layers which are fixed on insulation material and roof structure. The global heat resistance (Rc) within a green roof is affected by the humidity content of the substrate layer in which the coarse recycled materials can be used. Moreover, the utilization of recycled coarse aggregates such as incinerated municipal solid waste aggregate (IMSWA) for the drainage layer would be a promising solution, increasing the recycling of secondary resources and saving natural resources. Therefore, this paper aims to investigate the heat transfer across green roof systems with a drainage layer of IMSWA and a substrate layer including recycled tiles and bricks in wet and dry states according to ISO-conversion method. Based on the results, water easily flows through the IMSWAs with a size of 7 mm. Meanwhile, the Rc-value of the green roof system with the dry substrate (1.26 m2 K/W) was 1.7 times more than that of the green roof system with the unsaturated substrate (0.735 m2 K/W). This means that the presence of air-spaces in the dry substrate provided more heat resistance, positively contributing to heat transfer decrease, which is also dependent on the drainage effect of IMSWA. In addition, the Rc-value of the dry substrate layer was about twice that of IMSWA as the drainage layer. No significant difference was observed between the Rc-values of the unsaturated substrate layer and the IMSWA layer.

Download Full-text

On the green roof system. Selection, state of the art and energy potential investigation of a system installed in an office building in Athens, Greece

Renewable Energy ◽

10.1016/j.renene.2007.03.022 ◽

2008 ◽

Vol 33 (1) ◽

pp. 173-177 ◽

Cited By ~ 94

Author(s):

A. Spala ◽

H.S. Bagiorgas ◽

M.N. Assimakopoulos ◽

J. Kalavrouziotis ◽

D. Matthopoulos ◽

...

Keyword(s):

State Of The Art ◽

Green Roof ◽

Office Building ◽

Energy Potential ◽

Roof System ◽

System Selection

Download Full-text

Theoretical and experimental analysis of the thermal behaviour of a green roof system installed in two residential buildings in Athens, Greece

International Journal of Energy Research ◽

10.1002/er.1535 ◽

2009 ◽

Vol 33 (12) ◽

pp. 1059-1069 ◽

Cited By ~ 49

Author(s):

Aikaterini Sfakianaki ◽

Elli Pagalou ◽

Konstantinos Pavlou ◽

Mat Santamouris ◽

M. N. Assimakopoulos

Keyword(s):

Thermal Behaviour ◽

Experimental Analysis ◽

Residential Buildings ◽

Green Roof ◽

Roof System

Download Full-text

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

Israel Journal of Ecology and Evolution ◽

10.1163/22244662-bja10025 ◽

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.

Download Full-text