• Title/Summary/Keyword: Paved Area

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Sensitivity analysis of effective imperviousness estimation for small urban watersheds (도시 소유역 유효불투수율의 민감도 분석)

  • Kim, Dae Geun;Ko, Young Chan
    • Journal of Korean Society of Water and Wastewater
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    • v.23 no.2
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    • pp.181-187
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    • 2009
  • In this study, a runoff hydrograph and runoff volume were calculated by using the kinetic wave theory for small urban watersheds based on the concept of low impact development(LID), and the effective imperviousness was estimated based on these calculations. The degree of sensitivity of the effective imperviousness of small watersheds to the impervious to pervious area ratio, infiltration capability, watershed slope, roughness coefficient and surface storage depth was then analyzed. From this analysis, the following conclusions were obtained: The effective imperviousness and paved area reduction factor decreased as the infiltration capability of pervious area increased. As the slope of watersheds becomes sharper, the effective imperviousness and the paved area reduction factor display an increasing trend. As the roughness coefficient of impervious areas increases, the effective imperviousness and the paved area reduction factor tend to increase. As the storage depth increases, the effective imperviousness and the paved area reduction factor show an upward trend, but the increase is minimal. Under the conditions of this study, it was found that the effective imperviousness is most sensitive to watershed slope, followed by infiltration capability and roughness coefficient, which affect the sensitivity of the effective imperviousness at a similar level, and the storage depth was found to have little influence on the effective imperviousness.

Survey of the Land-Cover Type Pattern in High-rise Building (초고층 건축물 외부공간의 토지피복 변화에 관한 연구)

  • Hong, Suk-Hwan;Han, Bong-Ho;Kim, Hong-Soon
    • Journal of the Korean Institute of Landscape Architecture
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    • v.40 no.2
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    • pp.15-23
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    • 2012
  • This study was accomplished by analyzing the change of land cover pattern in high-rise buildings in Korea. For this study, we selected 15 locations of high-rise buildings. The ratio of average building coverage and paved area was 79.7%, and both green and water area were low, relatively. The biotope area factor of the site showed low percentage by 15.90% due to the underground space development. As a result of correlation analysis between the time of construction and land-cover type, building coverage has been decreased according to the stream of time. However, biotope area factor has been increased And, the paved area has m correlation. It was identified that reducing paved area is effective to enhance the ecological functions of a high-rise building outdoor.

Factor Analysis of the Relation Between Land Cover Ratio of Green Spaces and Temperature (공원녹지의 토지피복비율과 기온간의 요인분석)

  • Yoon, Yong-Han;Park, Bong-Ju;Kim, Won-Tae;Park, Sun-Young
    • Journal of Environmental Science International
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    • v.17 no.5
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    • pp.485-491
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    • 2008
  • The present study examined the relation between land cover condition and temperature in various types of urban green spaces. The diagram of temperature distribution showed that high-temperature zones are formed around paved areas, and low temperature zone around planted areas and grassy areas. Even in planted areas where low-temperature zones were formed, temperature was different according to hierarchical structure. That is, temperature was relatively low in areas covered with arbor + sub-arbor. With regard to land cover ratio, the increase of planted areas and grassy areas had an effect on the fall of temperature and the effect was higher in order of planted areas and grassy areas. On the contrary, paved areas and bare areas had an effect on the rise of temperature. According to the results of factor analysis, in case of the highest temperature, planted area and grassy area were put together into a factor lowering temperature, paved area and temperature into a factor raising temperature, and bare area alone into a factor of low significance. In case of the lowest temperature, grassy area and bare area were put together into a factor, and the validity of the factor analysis was proved by the analysis of urban heat islands. An increase in the number of trees by height was effective in lowering temperature, and the effect was high in order to arbor and sub-arbor, and the source of coldness in planted area was tall trees.

Analysis of the trend of atmospheric PM10 concentration over the Seoul Metropolitan Area between 1999 and 2008 (수도권 대기 미세먼지 1999-2008년 추이 분석)

  • Kim, Yong-Pyo
    • Journal of Environmental Impact Assessment
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    • v.19 no.1
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    • pp.59-74
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    • 2010
  • The trend of the PM10 concentrations in the Seoul Metropolitan Area (SMA) is reviewed and relative contributions of major contributors (paved road emissions and long-range transport from outside the SMA) are discussed. It was shown that the PM10 concentrations in the SMA have generally decreased except Incheon between 1999 and 2005. Further, it was identified that the difference of the PM10 mass concentration between the roadside stations and urban ambient stations has decreased between 2004 and 2008. Based on the emission estimates, it was suggested that the reduction of resuspension of aerosols on the road is the major reason for that. Based on the modeling results, it was identified that outside effects be about 30% of the ambient PM10 concentration in the SMA. Further research and policy issues to identify major sources of PM10 in the SMA are discussed.

Concentration Rise of Fine Particle according to Resuspended Dust from Paved Roads after Sudden Heavy Rain in Busan (부산 도심지역 기습 폭우 후 형성된 도로면 토사의 재비산에 의한 미세먼지 농도 상승)

  • Jeon, Byung-Il
    • Journal of Environmental Science International
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    • v.25 no.5
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    • pp.705-713
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    • 2016
  • This study investigates the concentration sudden rise in fine particle according to resuspended dust from paved roads after sudden heavy rain in Busan on August 25, 2015. The localized torrential rainfall in Busan area occurred as tropical airmass flow from the south and polar airmass flow from north merged. Orographic effect of Mt. Geumjeong enforced rainfall and it amounted to maximum 80 mm/hr at Dongrae and Geumjeong region in Busan. This heavy rain induced flood and landslide in Busan and the nearby areas. The sudden heavy rain moved soil and gravel from mountainous region, which deposited on paved roads and near roadside. These matters on road suspended by an automobile transit, and increased fine particle concentration of air. In addition outdoor fine particle of high concentration flowed in indoor by shoes, cloths and air circulation.

A Study on Empirical Method Analysis of Impervious Surface Using KOMPSAT-2 Image (KOMPSAT-2 위성영상을 이용한 불투수지도작성 방법에 관한 실증연구)

  • Bae, Da-Hye;Lee, Jae-Yil;Ko, Chang-Hwan;Ha, Sung-Ryong
    • Journal of Environmental Impact Assessment
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    • v.20 no.5
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    • pp.717-727
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    • 2011
  • Impervious surface affects urban climate, flood, and water pollution and has important role as basic data for urban planning and environmental and resources management uses. With a high paved rate, increased quantity of the outflown water and brings urban flooding during a heavy rain. Moreover, these non-point source pollution is getting increased the water pollution. In this regard, it is definitely important to research and keep monitoring the current situation of paved surface, which influences urban ecosystem, disaster and pollution. In this study, we suggest a method to utilize high resolution satellite image data for efficient survey on the current condition of paved surface. We analysed the paved surface condition of Dae-jeon metropolitan city area using KOMPSAT-2 image and validate its practicalness and limitation of this method.

A Study on Urban Environmental Climate Mapping Method for Sustainable Urban Planning in Daegu (대구지역의 환경친화적 도시계획을 위한 도시환경기후지도 작성에 관한 연구)

  • Park, Myung-Hee;Jung, Woo-Sik;Kim, Hae-Dong
    • Journal of Environmental Science International
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    • v.20 no.4
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    • pp.465-482
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    • 2011
  • To preserve atmospheric environment of urban areas, it needs to create urban space considering air pollution sources and natural and geographical properties such as wind circulation. According to this study could examine climate and environmental characteristics of Daegu and accordingly suggest a climate map in urban environment and an "advice map" in urban planning. The urban area(area paved with asphalt and concrete) of Daegu has increased by more than five times since 1960. In addition, the analysis of thermal environment through satellite data shows that the surface temperature between a place paved with artificial structures and a farmland shows $10{\sim}20^{\circ}C$ difference during the daytime in the summer. Regarding the parks inhibiting the heat island of a city have the small area of trees, and the road paved with concrete is wide so that they hardly serve as the source of heat absorption. As Apsan is located to the south of Daegu and Palgonsan to the north and Daegu has east high west low type, mountain wind from mountains in the south and north passes a city and delivers heat and air pollutions at night. In the west of Daegue, there is the poorest environment and industrial facilities and environmental basic facilities are mostly located, so large residential complexes that are being built around the industrial facilities as if they set up a folding screen and therefore the poor environment is increasingly worse.

Case Study of Geogrid Reinforcement in Runway of Inchon International Airport (지오그리드를 활용한 인천국제공항 활주로 보강사례)

  • 신은철;오영인;이규진
    • Proceedings of the Korean Geotechical Society Conference
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    • 1999.11c
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    • pp.105-116
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    • 1999
  • The Inchon International Airport site was formed by reclaimed soil from the sea. The average thickness of soft soil Is about 5 m and most of soft soils are normally consolidated or slightly over consolidated. There are many box culverts which are being constructed under the runways in the airfield. Sometimes, differential settlement can be occurred in the adjacent of box culvert or underground structures at the top layer of runway Soil compaction at very near to the structure is not easy all the time. Thus, one layer of geogrid was placed at the bottom of lean concrete layer for the concrete paved runway and at the middle of cement stabilized sub-base course layer for the asphalt paved runway. The length of geogrid reinforcement is 5m from the end of box culvert for both sides. The extended length of geogrid was 2m from the end of backfill soil in the box culvert. The tensile strength tests of geogrid were conducted for make sure the chemical compatibility with cement treated sub-base material. The location of geogrid placement for the concrete paved runway was evaluated. The construction damage to the geogrid could be occurred. Because the cement treated sub-base layer or lean concrete was spread by the finisher. The magnitude of tensile strength reduction was 1.16%~1.90% due to the construction damage and the ultimate tensile strength is maintained with the specification required. Total area of geogrid placement in this project is about 50,000 $m^2$.

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A Study on the Characterization of Land use in Urban Areas, according to Nonpoint Pollutant Source Runoff (도시지역 토지이용에 따른 강우사상별 비점오염물질 유출특성 파악)

  • Ryu, Je-Ha;Yoon, Chun Gyeong;Choi, Jae-Ho;Rhee, Han-Pil;Hwang, Mun-Yuong;Yang, Hwee-Jung
    • Journal of Korean Society on Water Environment
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    • v.29 no.3
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    • pp.309-316
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    • 2013
  • The Non-Point Sources shows different characteristics over a wide area depending on basin situation and rainfall events etc. In addition, Among various land uses in the urban areas, runoff appears high in the paved area, though small in its size, during a heavy rain than in other land use owing to its high impervious rate, and pollutants become severly accumulated owing to continual transportation of vehicles, characteristically showing high concentrations of runoff in the early stage. As a result, several advanced countries including USA give a special emphasis on the paved area as a target for supervision. In view of these aspects, the research is not only required to consider separated sub-basins which are distributed according to land uses, but also needed to develop a suitable monitoring which is reflected rainfall-runoff relation. The on-site monitoring has been performed to collect data in object watershed as well.