• Journal of the Korea Institute of Building Construction
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• v.8 no.6
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• pp.123-129
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• 2008

The purpose of this study is to test performances of 14 types of root barrier materials by applying testing plant: and soils suitable for weather and natural features of Korea. For testing Plants, Plioblastus pygmaed Mitford A and Pyracantha angustifolia have been selected. For testing soil, mixture of pearlite and peat moss in 3:1 ratio Testing container has been fabricated with duplicated structure having inner and outer containers. And the outer container has 2 hinges on its side wall to allow opening and closing. Wet rock wool with 50mm in thickness has been inserted between inner and outer containers to allow root to penetrate through root barrier material and continue to grow. We planted 12 Plioblastus pygmaed Mitford A. and 4 Pyracantha angustifolia per one testing container. Three testing samples have been made for 1 type of root barrier material, which become a total 42 specimens. Planted testing samples have been installed within the greenhouse, which will be observed regularly for 2 years from now on. We started test from July 11, 2008 and had performed intermediate observations every month for initial 3 months. From the 3rd intermediate observation on Sept. 18, we confirmed that 6 types of roe barrier materials have penetrated roots. Even though two types of them have been generally used as root barrier materials for roof planting system, all of three testing samples have a lot of penetrated roots. This result proves that it is not reasonable to introduce testing methods of root barrier from Europe. USA or Japan.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2008.11a
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• pp.245-249
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• 2008

The purpose of this study is to test performances of 14 types of root barrier materials by applying testing plants and soils suitable for weather and natural features of Korea. For testing plants, Plioblastus pygmaed Mitford A. and Pyracantha angustifolia have been selected. For testing soil, mixture of pearlite and peat moss in 3:1 ratio(volume). Testing container has been fabricated with duplicated structure having inner and outer containers. And the outer container has 2 hinges on its side wall to allow opening and closing. Wet rock wool with 50mm in thickness has been inserted between inner and outer containers to allow root to penetrate through root barrier material and continue to grow. We planted 12 Plioblastus pygmaed Mitford A. and 4 Pyracantha angustifolia per one testing container. Three testing samples have been made for 1 type of root barrier material, which become a total 42 specimens. Planted testing samples have been installed within the greenhouse, which will be observed regularly for 2 years from now on. We started test from July 11, 2008 and had performed intermediate observations every month for initial 3 months. From the 3rd intermediate observation on Sept. 18, we confirmed that 6 types of root barrier materials have penetrated roots. Even though two types of them(EDPM Sheet, Polyethylene Sheet) have been generally used as root barrier materials for roof planting system, all of three testing samples have a lot of penetrated roots. This result proves that it is not reasonable to introduce testing methods of root barrier from Europe or Japan.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2018.05a
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• pp.103-104
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• 2018

Recently, in addition to greening of roof and artificial soil, Rootproofing to prevent damage to the waterproof layer and structures by roots is recognized as an important task. Therefore, various related products and construction methods have been developed and applied in the field. However, in the case of synthetic polymer-based sheets most commonly used in domestic construction sites, Most are produced using 100% new materials that are not suitable for green trends such as resource conservation and environmental protection. Therefore, in this study, we developed TPO sheet using recycled material, which is a technology that can secure eco-friendliness by utilizing recycled resources. As a result of the evaluation of tensile performance of the TPO sheet according to the recycled material content, The tensile strength of the specimens with the recycled content of 50 ~ 70% was the highest, The elongation rate of the specimen with the recycled content of 30 ~ 40% was the best.

• Journal of the Korean Institute of Landscape Architecture
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• v.45 no.2
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• pp.11-22
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• 2017

To successfully create a low-carbon landscape in order to become a low-carbon city, it is necessary to understand the dynamics of artificial greening's resources on a multi-scale. Additionally, the effects of carbon storage should be quantitatively evaluated. The purpose of this study is to simulate and evaluate the changes in carbon storages of artificial ground trees using system dynamics throughout a long-term period. The process consisted of analyzing the dynamics of the multi-scale carbon cycle by using a casual loop diagram as well as simulating carbon storage changes in the green roof of the Gangnam-gu office building in 2008, 2018, 2028, and 2038. Results of the study are as follows. First, the causal loop diagram representing the relationship between the carbon storage of the artificial ground trees and the urban carbon cycle demonstrates that the carbon storage of the trees possess mutual cross-scale dynamics. Second, the main variables for the simulation model collected 'Biomass,' 'Carbon storage,' 'Dead organic matter,' and 'Carbon absorption,'and validated a high coefficient of determination, the value being ($R^2$=0.725, p<0.05). Third, as a result of the simulation model, we found that the variation in ranking of tree species was changing over time. This study also suggested the specific species of tree-such as Acer palmatum var. amoenum, Pinus densiflora, and Betula platyphylla-are used to improve the carbon storage in the green roof of the Gangnam-gu office building. This study can help contribute to developing quantitative and scientific criteria when designing, managing, and developing programs on low-carbon landscapes.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.14 no.1
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• pp.77-88
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• 2011

This study was carried out to investigate the effects of soil depth and planting density on the growth of lettuce, crown daisy, and strawberry on a rooftop condition using artificial soil as a growth media. The vegetable crops showed better growth for plant height (cm), plant width (cm), plant fresh weight (g), and Fo, Fm and Fv/m on 20cm depth soil than 10cm depth soil except strawberry. Planting density of $16/m^2$ and $64/m^2$ did not show significant differences on the growth of the crops. Soil moisture content and EC were low for 10cm depth soil in lettuce plots, whereas there was no significant differences on soil moisture and EC between two soil depth in strawberry plots. Hunter's L, a, and b values showed the leaf color of lettuce dark green on 20cm depth soil and reddish on 10cm depth soil. Results showed that soil depth suitable for crop growth on rooftop conditions was 20cm rather than 10cm. Growth response of the crops showed no significant difference between $16/m^2$ and $64/m^2$, indicating that planting density of 64 $plants/m^2$ could be practiced on rooftop conditions. Lettuce growth rapidly changed in control treatment in which leaves were not pinched out, while slowly changed in plants which leaves were periodically pinched out. In the case of control plot, it was impossible to harvest because withering of lower leaves after blossom on June 22. The plant of crown daisy in which pinching was not conducted, blossomed on June 7, and the plants were removed since its aesthetical value was lost. Strawberry seemed to be a suitable vegetable crop for rooftop conditions based on its high covering rate and extended growth period until late October. The soil depth 20cm and planting density 64 $plants/m^2$ were suitable for vegetable crops on green roof system using artificial soil.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.8 no.4
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• pp.12-22
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• 2005

The purpose of this study is to select suitable planting base for the mat-type rooftop greening in order to popularize rooftop greening system easily. The experiment was conducted from 2004 June to 2005 May under several conditions; 4 soil depths under mats(2cm, 5cm, 10cm, 15cm), two soil mixtures(natural soil 80%+leaf mold 20%, artificial soil) and two light conditions(full sun place, 20% shaded place). In this experiment, 3 types of mats were used ; the herbaceous plants mat(11 plants inclusive of Lotus corniculatus L., Silene armeria L.), the lawn mat with Festica arundinacea and Sedum mat with Sedum kamtschaticum, Sedum sarmentosum, Sedum oryzifolium, Sedum middendorffianum. The result is as follows; in the mat-type rooftop greening, the herbaceous plants mat, lawn mat and sedum mat are the similar number of plant and effect of greening on soil depth 2cm, 5cm and 10cm, 15cm. So suitable soil depth of rooftop greening is 10cm for the load and economical factor. Thus the mat-type rooftop greening possible planting base depth of all 13cm as soil depth 10cm and mat depth 3cm. As soil mixtures, the number and growth of plants were better mat and 'natural soil 80% +leaf mold 20%' than mat and artificial soil. In herbaceous plants mat, Silene armeria L., Dianthus chinensis, Centaurea cyanus L., Lotus corniculatus L. are survival in full sun place and Silene armeria L., Dianthus chinensis, Centaurea cyanus L. are survival in 20% shaded place. In conclusion, selection of suitable soil mixtures and plants is possible extensive management rooftop greening with effect of continuous greening. The mat-type rooftop greening are lightweight and simple preparation without management and can popularize readily.

• Journal of Environmental Impact Assessment
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• v.24 no.1
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• pp.16-34
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• 2015

Impervious covers(IC) are artificial structures, such as driveways, sidewalks, building's roofs, and parking lots, through which water cannot infiltrate into the soil. IC is an environmental concern because the pavement materials seal the soil surface, decreasing rainwater infiltration and natural groundwater recharge, and consequently disturb the hydrological cycle in a watershed. Increase of IC in a watershed can cause more frequent flooding, higher flood peaks, groundwater drawdown, dry river, and decline of water quality and ecosystem health. There has been an increased public interest in the institutional adoption of LID(Low Impact Development) and GI(Green Infrastructure) techniques to address the adverse impact of IC. The objectives of this study were to construct the modeling site for a samll urban watershed with the Storm Water Management Model(SWMM), and to evaluate the effect of various LID techniques on the control of rainfall runoff processes and non-point pollutant load. The model was calibrated and validated using the field data collected during two flood events on July 17 and August 11, 2009, respectively, and applied to a complex area, where is consist of apartments, school, roads, park, etc. The LID techniques applied to the impervious area were decentralized rainwater management measures such as pervious cover and green roof. The results showed that the increase of perviousness land cover through LID applications decreases the runoff volume and pollutants loading during flood events. In particular, applications of pervious pavement for parking lots and sidewalk, green roof, and their combinations reduced the total volume of runoff by 15~61 % and non-point pollutant loads by TSS 22~72 %, BOD 23~71 %, COD 22~71 %, TN 15~79 %, TP 9~64 % in the study site.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.8 no.4
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• pp.23-31
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• 2005

Green spaces in cities were insufficient and decreased as artificial structures increase. Accordingly, greening rooftop space contributed to urban ecosystems as green space. Especially, since 2002 Seoul supported rooftop greening and introduced 'Ecology-area rates'. Thus rooftop greening had the potentiality of extension. This prepared the extensive rooftop greenings within planting-base for extensive management rooftop greening system to be easily popularized. The extensive rooftop greening conducted from 1997-2005 reported that soil depth was 8cm and soil mixtures were 5 types. And plant were Crysanthemum zawaskii var. latilobum, Aster hayatae, Crysanthemum zawaskii herb. ssp. coreanum, Sedum sarmentosum, Sedum rotundifolium, Sedum oryzifolium, Sedum takemensis, Sedum middendorffianum, Sedum telerium var. purpureum, Sedum spectabile, Carypteris incana, Dianthus superbus, Hosta minor. As a result, for nine years after the modular type rooftop greening established, survival plants were Sedum takemensis, Sedum sarmentosum, Sedum spectabile, Sedum middendorffianum, Carypteris incana, Crysanthemum zawaskii var. latilobum, Sedum telerium var. purpureum, Sedum rotundifolium, Dianthus superbus. Also effect of greening was possibled soil depth 8cm. And growth of plants from 1997 to 2005 were fine on two soil mixtures of 'perlite+peatmoss+vermicompost+moisturizer' and 'perlite+moisturizer+bark(mulching)'. Invasive plants are Ixeris dentata Nakai, Ixeris chinensis var. strigosa, Youngia sonchifolia, Eragrostis ferruginea, Aster pilosus Willd., Ixeris japonica Nakai, Valpia myuros, and Setaria viridis. In conclusion, selection of suitable native plants was possible extensive management rooftop greening with effect of continuous greening. The extensive rooftop greening were lightweight and simple preparation without management and can popularize readily.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.19 no.1
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• pp.1-11
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• 2016

Currently, urban green space is disappearing due to urbanization, industrialization and various environmental problems including the disruption of the ecology in urban areas. To solve such problems and increase urban green area, roof greening has been suggested as an alternative. Through observing the responses of three plant species (Mukdenia rossii, Dianthus chinensis, and Pachysandra terminalis) plantrd on the soil mixed with Geohumus, this study investigated the effect of Gehumus on soil water content and plant survival. Soil water content of the rooftop soils has been increased when mixed with Geohumus. The responses were proportional to the amount of Geohumus in the mixture. Geohumus exerted a stronger influence on raising soil moisture content for soil A which had lower water-holding capacity. The stress responses of the plants varied in relation to the amount of Geohumus and soil moisture content. The stress response was lowest for Dianthus chinensis and increased in the order of Mukdenia rossii and Pachysandra terminalis. With the highest plant stress, Pachysandra terminalis showed the lowest survival rate among the three species. Without irrigation, the plants survived only for six weeks on green roofs. The survival rate differed depending on the amount of Geohumus mixed. The results of the experiment showed, with some exceptions, that Geohumus helped to improve soil water content, reduce plant stress, and extend plant survival period.

• Journal of the Korean Institute of Landscape Architecture
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• v.31 no.5
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• pp.58-72
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• 2003

Rooftop greenery has been used as a way to solve urban environmental problems by creating green space in densely populated cities. This study was carried out to suggest more effective designs for roof-garden at hospitals through a post-occupancy evaluation. The roofgarden of Asan Medical Center was evaluated with regards to setting, proximate environmental context, users, and design activity by a multi-method including plan investigations, observations, in-depth interviews and questionnaires. The results are summarized as follows; the users' main activities included resting, walking, and talking. A number of users were observed at shaded spaces sitting on such things as benches, pergolas, and shelters. The satisfaction of the users showed high satisfaction level except in the amount of shade, facilities, and shelter. The variables affecting a overall satisfaction were ‘accessibility’, ‘safety’, ‘quality of surroundings’, and ‘suitability for speculation’. By comparing the design concept with using pattern, designer's intention was not reflected sufficiently in several aspects such as ‘event deck for therapy programs’, ‘grove and path’, and ‘low planters’. This study suggests some design implications; it is necessary to furnish shaded sitting places for passive behaviors and pathways for walking or a light exercise. A wind-break wall with glass windows could widen the users' views in a limited space. Natural shade like tree shade or pergola are more desirable than artificial shades. As for the vertical location of the roofgarden, the middle floor could be better than top area for accessibility. Characteristics of building and users should be considered in detail to provide distinct spaces. Proper technical standards for the greening of artificial ground should be established.