• Journal of Environmental Science International
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• v.16 no.5
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• pp.603-610
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• 2007

Recent urban sprawl has destroyed various kinds of green space in tile city. It has affected duality of people's life in the city, as well as urban ecosystem. Recent study shows the possibilities of roofs as green spaces in urban central site where the land costs are generally high. This research focuses on Jung-Gu district in Daegu Metropolitan city as a study area and calculates possible area of green roof using 2002 Autocad program based on aerial photographs and land registration maps. And the purpose of this research is to analyze environmental and economic effects of green roof. The environmental effects are as follows. It is expected that $91,106m^2$ green spaces, 12.13 % of study site, will be added if green roof is performed in the study site. It is assumed that the expanded areas could reduce the highest temperature to $0.5-1.0^{\circ}C$ during the summer in terms of environmental effect. And the following shows the economic effects. If green roof and greening urban central site are created as a same size of $91,106m^2$, it will be expected that the costs of green roof will be much more in-expensive than about 98 billions won. It will be also found that the expense of cooling energy can be saved out about 8 millions won per day in summer, if grass planting is accomplished on the possible areas of green roof in the study site. Therefore, it is desirable to take legal supports such as enacting regulations to activate green roof for more environmental and economic effects. For instance, green roof for public institutions, school and model area selection are desirable method to publicize the effect of greening program for citizen's participation.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.18 no.1
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• pp.115-125
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• 2015

This study was carried out to analyze comparison of carbon storage and physicochemical properties of vegetation soil for extensive green rooftop established at Seoul National University in september 2013. For this study, 42 plots were made by 2 kinds of vegetation soil including A-type and B-type. A-type vegetation soil plots were made of 90% perlite and 10% humus and B-type vegetation soil plots were made of 60% perlite, 20% vermiculite, 10% coco peat and 10% humus. This study used 6 kinds of plants which are Aster koraiensis, Sedum takesimense, Zoysia japonica Steud, Euonymus japonica, Rhododendron indicum SWEET and Ligustrum obtusifolium. Field research was carried out in 11 months after planting. Physiochemical properties of B-type vegetation soil plots were better than A-type vegetation soil plots in every way and soil carbon content was also higher at B-type vegetation soil plots as well. B-type vegetation soil plots were maintained 10 to 20% higher soil water content than A-type vegetation soil plots of the study period. The species of herb which showed the best carbon storage was Zoysia japonica Steud at B-type vegetation soil plots. The species of shrub which showed the best carbon storage was Ligustrum obtusifolium at B-type vegetation soil plots. Plants generally showed better growth at B-type vegetation soil plots and B-type vegetation soil plots were higher than A-type vegetation soil plots in soil carbon stock.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.16 no.4
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• pp.27-40
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• 2013

These day morden cities have serious climatic problems due to enviornmental load caused by excessive development of urbanization. As technological improvement to answer to various ecological disasters and climate changes are also called on the field of construction, inter-disciplinary studies linked to the estabilishment of sustainable energy generation systems and enviornmental control is needed in a consilient point of view. This study aims to analyse optimal site conditions for photovoltaic system and green roof planting through solar radiation simulation in a integrated perspective. In so doing, it seeks to proffer basic study for developing a sound use of roof area that is sustainable in environmental and resources aspects. A computer simulation showed that, in the case of total seasonal solar radiation, summer season resulted 312.5kWh in 35% of total annual solar radiation. This season indicated the lowest radiation rate of the year for direct sunlight in 45.8% of total seasonal solar radiation. Due to such solar radiation simulation, at the largest optimal planting area, Glechoma hederacea var. longituba secured $719.16m^2$ of gross roof area.

• Journal of the Korean Institute of Landscape Architecture
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• v.41 no.6
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• pp.140-146
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• 2013

This experiment was conducted in order to study the physiological characteristics of Sedum takevimense in different moisture conditions. The photosynthetic rate, water use efficiency and the respiratory rate were determined by using a photable photosynthesis system. According to the results, the best illumination range and moisture range were explicitly selected. The highest photosynthetic rate was at $600{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$, and after this value, the trend showed a reduction. When the moisture was 11.31%, the photosynthetic capacity and water use efficiency reached maximum value, but the respiratory rate reached maximum value at 7.91%. According to the measured values, the best illumination range was $600{\sim}1,200{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ and the best moisture range was 7.09~11.31%.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.17 no.3
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• pp.1-11
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• 2014

Recently, major cities in Korea are suffering from frequent urban flooding caused by heavy rainfall. Such urban flooding mainly occurs due to the limited design capacity of the current drainage network, which increases the vulnerability of the cities to cope with intense precipitation events brought about by climate change. In other words, it can be interpreted that runoff exceeding the design capacity of the drainage network and increased impervious surfaces in the urban cities can overburden the current drainage system and cause floods. The study presents the green roof as a sustainable solution for this issue, and suggests the pre-design using the LID controls model in SWMM to establish more specific flood prevention system. In order to conduct the computer simulation in connection with Korean climate, the study used the measured precipitation data from Cheonan Station of Korea Meteorological Administration (KMA) and the forecasted precipitation data from RCP 8.5 scenario. As a result, Extensive Green Roof System reduced the peak runoff by 53.5% with the past storm events and by 54.9% with the future storm events. The runoff efficiency was decreased to 4% and 7%. This results can be understood that Extensive Green Roof System works effectively in reducing the peak runoff instead of reducing the total stormwater runoff.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.8 no.1
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• pp.88-99
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• 2005

This research aimed to investigate the current trends of rooftop greening techniques of frequent use within and without Korea. It is also expected that this research will help developing new rooftop greening techniques appropriate for Korean environment. Data for this study have been collected from patent applications for rooftop greening techniques; the web sites of the Korean Intellectual Property Office as well as patent offices in Germany and Japan, where active researches on rooftop greening techniques are in progress. 168 applications within a period from the year of 1984 to December of 2004 were examined, among which Japan excelled with its 81 applications followed by Germany(54), Korea(31)and USA(2). In case of Japan, where more patent applications were found than in any other countries, applications for Plant Base(38) excelled others - System(36), Management(4) and Plant(3) in the number of applications. As for Germany, 25 cases were on Plant Base, 25 cases on System, and 4 cases on Plant; in Korea, 15 cases were on Plant Base, 11 cases on System, 3 cases on Plant and 2 cases on Management; in USA, 1 cases were on System and 1 cases on Plant. Overall, the total number of patent applications in three countries reaches 168 cases; among which Plant Base topped in all four countries, followed by 73 cases on System. Applications concerning Plant and Management totalled to 11 and 6 for each. In conclusion, most patents were concentrated on Plant Base and System while researches on Plant and Management still do not get as much attention as they deserve. Research and development of various techniques on Plant must be a precondition for the formation of diverse Bio-tops suitable for the environments of specific areas. Concrete researches on rooftop greening techniques will contribute to the improvement of urban ecosystem by developing more convenient and easily applicable techniques during the time of actual construction.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.15 no.2
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• pp.137-147
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• 2012

GRS is an effective urban ecology restoration technique that can manage a variety of environmental functions such as ecological restoration, rainwater spill control and island heat effect from a low-impact development standpoint that can be utilized in new construction and retrofits. Recently, quantitative evaluation studies, both domestic and abroad, in the areas related to these functions, including near-earth surface climate phenomenon, heavy rainwater regulation, thermal environment of buildings, have been actively underway, and there is a trend to standardize in the form of technological standards. In particular, centered on the advanced European countries, studies of standardizing the specific insulation capability of buildings with green system that comprehensively includes the green roof, from the perspective of replacing the exterior materials of existing buildings, are in progress. The limitation of related studies in the difficulties associated with deriving results that reflect material characteristics of continuously evolving systems due in part to not having sufficiently considered the main components of green system, mechanisms of vegetation, soils. This study attempts to derive, through EnergyPlus, the effects that the vegetation-related indicators such as vegetation height, FCV, etc. have on building energy load, by interpreting vegetation and soil mechanisms through plant canopy model and using an ecological standard indicator LAI that represent the condition of plant growth. Through this, the interpretations that assume green roof system as simple heat insulation will be complemented and a more practical building energy performance evaluation method that reflects numerical methods for heat fluxes phenomena that occur between ecology restoration systems comprised of plants and soil and the ambient space.

• Journal of Environmental Science International
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• v.19 no.7
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• pp.843-848
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• 2010

This study focused on the characteristics of change soil water with respect to soil thickness and soil mixture ratio, in order to effectively carry out an afforestation system for a roof with a low level of management and a light weight. Soil hardness tended to increase as sand particle was increase regardless soil thickness and soil porosity had more higher artificial soil than natural soil mixture. In case of soil pH, natural soil mixture had between 6.7 and 7.4, and artificial soil mixture had 6.0~6.8. Organic matter, electrical conductance and exchangeable content were highest in $L_{10}$, which it had the highest leafmold ratio. Soil moisture tension(kPa) in 15cm soil thickness was observed natural soil mixture had a considerable change but artificial soil mixture had a gradual change when non-rainfall kept on. In the experimental $L_{10}$, $S_{10}$, $S_7L_3$ and $S_5L_5$ object, the amount of moisture tended to rapidly decrease. However, in the experimental $P_7P_1L_2$, $P_6P_2L_2$, $P_5P_3L_2$ and $P_4P_4L_2$ objects, which contained pearlite and peat moss, the amount of moisture tended to gradually decrease. As a result, the use of a artificial soil mixture soil seems to be required for the afforestation of a roof for a low level of management.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.17 no.1
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• pp.135-146
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• 2014

The improvement of adaptation capability against heat island (ACHI) by greening buildings is considered as an important measure to cope with a climate change. This study aimed to select the most appropriate zones for green roof initiative in case study sites, Bucheon, Anyang, and Suwon Cities and to investigate the characteristics of buildings for greening to improve ACHI. Relative ACHI for each lot was estimated from 0 to -9, assuming that it decreases with the distance from green space and waterbody. Low adaptation capabilities were mostly shown in the old urban blocks with dense low-rise buildings and lack of green space. Three blocks with the lowest ACHIs were chosen as a green roof initiative zone in each city. They are largely residential areas including low-rise buildings such as single, multi-household houses, townhouses, 5 or lower story apartments and few are industrial areas crowded with small factory buildings. The areas of building roof available for greening are 8.8% within the selected zones in Bucheon City, 5.3% in Anyang City, and 4.9% in Suwon City. As it were, 25.2~41.7% of the roof top areas are available for greening in these zones. It means that roof top areas of $25,000{\sim}120,000m^2$ can be used for greening within the selected zones of $0.64{\sim}1.65km^2$ to improve ACHI. The approach and results of the study are significant to provide a logical basis and information on location, scale, effect, and target figure of greening as a measure to cope with climate change.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.15 no.1
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• pp.107-117
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• 2012

We estimated the potential area roof greening in Gyeonggi-do that will mitigate the heat island effect. The estimation was based on building age, roof shape, and building use which were recorded in the building register from "Sewoomteo, the Building Administration System in the Ministry of Land, Transport and Maritime Affairs. The estimated potential roof greening area in Gyeonggi-do was approximately $102.5km^2$ assuming that the buildings for residence, public, education(school), office, shopping mall are appropriate for roof greening. The area occupied by apartment buildings over six-story was 76.3% of the potential roof greening area 10.2% for individual houses, 5.9% for under five-story apartment buildings, and 3.7% for school buildings. The result indicated that it is residential buildings that we need to pay attention for roof greening, especially high-rise buildings over six-story. Greening of the whole estimated area, $102.5km^2$, in Gyeonggi-do will result in the increase of green space per capita by $8.74m^2$. This is 1.65 times greater than the area of current urban parks, and 1.97 times greater than the total area of neighborhood parks, children's parks, and pocket parks. Greening of the estimated roof area will increase green coverage of urban area by twice, adding to current green coverage of the urban areas, 11.3%, in 10 major cities. In particular, the effect of roof greening would be remarkable in inceasing the green space of Anyang City, Gwangmyeong City, and Guri City where neighborhood park area falls short.