• Title/Summary/Keyword: natural environment zone

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A Study on the Optimum Environmental Conditions for the Creation and Restoration of Artificial Tidal Flat (인공간석지 창출과 복원을 위한 최적환경조건 선정에 관한 연구)

  • Lee Jeoung-Gyu;Okada Mitsumasa
    • Journal of the Korean Society for Marine Environment & Energy
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    • v.2 no.1
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    • pp.102-112
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    • 1999
  • The purpose of this study is to evaluate the effects of design criteria and environmental conditions of the site of created tidal flats on the structure and function of man-made ecosystem. Seven constructed tidal flats and three natural tidal flats were studied taking the difference in the location (wave height and tidal current), inflow of river water, slope of tidal flat and age after the construction completed into consideration. Parameters studied were physico-chemical and biological characteristics of soils and rate of respiration. The natural tidal flats had higher contents of silt, nitrogen and organic matter compared with the constructed ones. The natural ones had reductive zone below 2cm, whereas the constructed ones had aerobic zone from the surface to below 20cm. The bacterial population in the soil of the constructed tidal flats was one to two orders of magnitude lower than that in the natural ones. Both biomass of macrobenthos and microbial respiration rate, however, were not different significantly between the natural and the constructed tidal flats. There was an exceptional constructed tidal flat with similar physico-chemical and biological characteristics to the natural ones. It is most probable that sufficient conditions to have similar tidal flats to natural ones are the location in enclosed bay or calm coastal area. Thus, to make man-made tidal flats with the same characteristics as those in natural ones, man-made tidal flats should be designed and/or located to enhance the accumulation of silt on tidal flat. It is important to select a place having low water motion for construction of tidal flat.

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Establishing a Green Space Management Zone for an Environmental City - Focusing on Changwon City - (환경도시 건설을 위한 도시녹지의 관리권역 설정 - 창원시를 대상으로 -)

  • Jung, Sung-Gwan;Lee, Woo-Sung
    • Journal of the Korean Institute of Landscape Architecture
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    • v.35 no.6
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    • pp.64-73
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    • 2008
  • The purpose of this study is to classify urban green space, to assess an imbalance by an administrative district (Dong), and to establish the management zone of urban green spaces for the construction of an environmental city in Changwon. The spatial data of 1:5,000 digital maps, park data in Changwon, land cover by the Ministry of Environment, and IKONOS satellite images from 2003 were used for this analysis. The assessment of the imbalance of urban green spaces was analyzed with the Lorenz curve and Gini's coefficient. The establishment of the management zone was performed by network analysis of GIS. The results of this study are as follows: the urban green spaces were classified as a park green space, a natural green space, and a riparian green space. According to the results of assessment of the imbalance of green spaces, Gini's coefficient was analyzed at higher than 0.4. Thus, the spatial imbalance of urban green spaces in Changwon was evident. The management zones to solve the imbalance were established: "rich zone", "fair zone", "poor zone" and "broken zone". Therefore, the rich and fair zones which have rich green spaces must maintain the good conditions through analysis of the green network and a survey of civic attitudes. The poor and broken zones which have poor green spaces must improve quality and quantity through creation of additional green spaces, construction of an eco-industrial park, and utilization of children's parks and pocket parks.

A Study on Wind-drift Sand Deposition by Vegetation and Coastal Debris using a Wind Tunnel Test (식생 및 해안표착물에 의한 비사 퇴적 풍동실험 연구)

  • Je, Young Jun;Jeon, Yong Ho;Yoon, Han Sam
    • Journal of the Korean Society for Marine Environment & Energy
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    • v.16 no.3
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    • pp.163-170
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    • 2013
  • The correlation and interaction mechanisms between marine debris and the vegetation zone were studied on the Jinu-do natural beach of the Nakdong river estuary. Laboratory wind tunnel experiments were carried out under the wind-field and bottom-sand conditions using wind tunnel test equipment to investigate the sedimentation characteristics of wind-drift sand deposition around marine debris and the vegetation zone. The major environmental factors/loads considered in this study were the motion of sand by wind on the beach, deposition of marine debris, and change in the vegetation zone/line. When the marine debris was installed in the wind tunnel, deposition at the front of the structure appeared first by wind action, and then deposition developed from behind at 70% of the front ground level. In contrast, in the case of vegetation, the deposition phenomenon appeared first from behind the vegetation zone/line, and was 60% higher than the front. When the height of the debris and vegetation was the same, the required experimental time to bury the vegetation completely was about twice that of the marine debris.

Diagnosis of Collegian's Adaptation Level for Autumn Environment (가을철 온열환경에 대한 대학생의 적응수준 진단)

  • Kim, Yang-Weon
    • Fashion & Textile Research Journal
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    • v.1 no.1
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    • pp.12-17
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    • 1999
  • The actual clothing conditions were surveyed to diagnose clothing condition of collegians in the view point of adaptation to the thermal environment in fall. Then, clothing climate, physiological responses, and subjective sensation were investigated through wearing trials on human subjects in climatic chamber based on the results from the survey. Factors to evaluate validity of clothing condition were clothing weight, clothing climate, physiological responses of human body, and subjective sensation. Adaptability of this research to thermal environment was compared to the results of Toda's and Duno's of Japan, Chung's results of Korea rural area, and Winslow's clo value. The standard values for wearing trials were values at comfortable zone, such as $32{\pm}1^{\circ}C$ of temperature and $50{\pm}10%$ of humidity inside clothing, $36.5{\sim}37.3^{\circ}C$ of ear temperature and $32.2{\sim}34.3^{\circ}C$ of mean skin temperature. Clothing weight per body surface area was 680.9 $g/m^2$ in male and 526.7 $g/m^2$ in women. Cold resistance ability of collegians was superior to Japanese and American, and similar to rural male in Korea. According to the examination of clothing adaptability with clothing weight from the investigation on physiological responses and the actual clothing conditions survey, following were found. Temperature inside clothing ($29.8{\sim}32.3^{\circ}C$) was normal, and humidity inside clothing (32.2~54.8%) was at comfortable zone. Mean skin temperature was at its comfortable zone. Therefore, 615 $g/m^2$ in male and 525 $g/m^2$ in female were a desirable wearing condition.

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Changes in Benthic Macroinvertebrate Communities in Response to Natural Disturbances in a Stream

  • Bae, Mi-Jung;Park, Young-Seuk
    • Journal of Ecology and Environment
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    • v.32 no.3
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    • pp.197-206
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    • 2009
  • Benthic macroinvertebrate communities were collected from six different sites in the Dobong Stream in Seoul, Korea to investigate spatial and temporal changes in benthic macroinvertebrate communities in response to natural disturbances such as floods and droughts. We collected samples monthly or semimonthly with a Surber net ($30cm{\times}30cm$), and measured environmental factors, including stream temperature, discharge, width, conductivity, dissolved oxygen and pH at each sampling site. Benthic macro invertebrates were strongly affected by floods as well as droughts. In addition, benthic macroinvertebrate communities displayed different responses to the onset of the rainy season in summer 2006 and 2007, apparently due to differences in the intensity and amount of precipitation. Chironomids were particularly sensitive to heavy rain. Floods and droughts also affected the proportions of functional feeding groups during the survey period: the proportion of scrapers was high right after heavy rains, while the proportion of predators tended to increase in intermittent-type streams as the riffle zone decreased. Finally, although species richness and abundance were strongly influenced by heavy rain, they recovered to background levels for within one month, and varied consistently among stream types, indicating habitat stability.

Comprehensive Field Measurement of Indoor Air and Thermal Quality in Naturally Ventilated Office Building with Double-Skin Façade

  • Ito, Kazuhide;Shiraishi, Yasuyuki
    • International Journal of High-Rise Buildings
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    • v.2 no.4
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    • pp.293-314
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    • 2013
  • Double-Skin Façade (DSF), which is a kind of passive indoor environmental control technique, is effective way to control environmental loads while maintaining the transparency especially in perimeter zone and hence the adoption example of DSF keep increasing recently. The objective of this study was to perform a field survey of air quality environment with natural ventilation through DSF and thermal environment within office building with six stories during a mild climate period in Japan. Moreover, to understand the comprehensive environmental performance of the target building, questionnaire survey was conducted to subjectively evaluate the productivity and satisfaction with the environmental factors in office space. In this field measurement, there was a positive correlation between the DSF internal ventilation flow and the amount of solar radiation on the DSF normal surface; the primary driving force for ventilation in the DSF was considered to be the buoyancy force caused by solar radiation. The results of questionnaire survey with regard to productivity level indicated the need for improvement in the thermal (temperature) and spatial environment (room size and furniture placement).

Satisfaction Level & Improvement Priority of Community Environment According to the Development Concepts of Residential Complexes - The Case of The 3 Residential Complexes in Cheongju Area - (택지개발지구 특성에 따른 거주자의 생활권 내 근린환경만족도 및 개선우선지수 - 청주권 3개 택지개발지구를 중심으로 -)

  • Lee, Sang-Un;Park, Kyoung-Ok
    • Journal of the Korean housing association
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    • v.21 no.3
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    • pp.77-86
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    • 2010
  • This study has the purpose to reveal the differences of residents' satisfaction level & demand of community environment and recognized residents' improvement priority of community environment at 3 complexes at the big city in the provinces. The 3 residential complexes had differentiated developmental concepts; the residence-oriented complex, the residence-government mixed complex with an eco-friendly concept, and the outskirt residence-industry mixed complex. Followings are the results of the study. 1) The satisfaction of residents in the community environment correlates with the increasing convenience facilities after construction. In the new outskirt complexes of smaller cities, dissatisfaction occurs more with public transportation rather than the road system, so that efficient public transportation systems, inner and neighboring areas, is requisite. 2) Even in the residence-oriented complex, the education environment does not entirely account for satisfaction level; the green environment is also second in priority after the education environment. In the residence-government mixed complex with an eco-friendly concept, a good natural environment does not entirely account for satisfaction level; education environment is also second in priority after the natural environment. The supply of sufficient schools may be fulfilled in the ways of reform of the education zone with neighboring existing residential areas. In the outskirt residence-industry mixed complex of smaller cities, priority was placed more on the location and convenience; this explains the complex's poor access to downtown.

Best Buffer Width of Riparian Buffer Zone using a Pilot with Different Plant Species for Reduction of Non-point Pollutant Loading (비점오염저감을 위한 수변완충지대의 적정 설계)

  • Kim, Sung-Won;Choi, I-Song;Oh, Jong-Min
    • Journal of Environmental Impact Assessment
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    • v.17 no.1
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    • pp.1-9
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    • 2008
  • Non-point pollution is caused by many diffusive sources, unlike a point pollution derived from industrial wastewater treatment plants or sewage treatment plants. Runoff of non-point pollutants is originated from rainfall or thawing in short period of time moving over and through the a ground surface. They cause ill effect on the quality of neighboring aquatic environment. To prevent effectively the wash off from non-point pollutant, it should be immediately reduced at the source or be treated after gathering of runoff water. This study has been carried out for the best width of riparian buffer zone. So we implemented the experiment in terms of its depth, width and kind of vegetations and calculated the reduction of pollutants loading. The experimental zone encompasses the watershed of Namhan River (Kyunggido Yangpyunggun Byungsanri). The region was divided into 5 land cover sectors : grass, reed, pussy willow, mixed(grass+pussy willow) and natural zone to compare effectiveness of vegetation. Water samples from four points have been collected in different depths. And the pollutant removal efficiency by sectors with different plant species was yielded through influent with one of each sample. And we obtained the correlation between the width of riparian buffer zone and the removal efficiency of pollutants. Using correlation result, the width of riparian buffer zones which needs to improve the water quality of river could be derived.

Thermophoretic deposition of soot particles in laminar diffusion flame along a solid wall in microgravity (미소중력환경에서의 고체벽면근방 층류확산염내 매연입자의 열영동 부착)

  • Choi, Jae-Hyuk;Osamu, Fujita;Chung, Suk-Ho
    • 한국연소학회:학술대회논문집
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    • 2007.05a
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    • pp.19-24
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    • 2007
  • The deposition behavior of soot particles in a diffusion flame along a solid wall was examined experimentally by getting rid of the effect of natural convection utilizing microgravity environment. The microgravity environment was realized by using a drop tower facility. The fuel for the flame was an ethylene ($C_2H_4$) and the surrounding oxygen concentration 35% with the surrounding air velocity of $V_a$=2.5, 5, and 10 cm/s. Laser extinction method was adopted to measure the soot volume fraction distribution between the flame and burner wall. The results show that observation of soot deposition in normal flame was difficult from buoyancy and the relative position of flame and solid surface changes with time. The soot particle distribution region moves closer to the surface of the wall as the surrounding air velocity is increased. And the experiments determined the trace of the maximum soot concentration line. It was found that the distance between soot line and flame line is around 5 mm. That is, the soot particle near the flame zone tends to move away from flame zone because of thermophoretic force and to concentrate at a certain narrow area inside of the flame, finally, to adhere the solid wall.

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Spatio-temporal Distribution of Macrobenthic Communities in Jinhae Bay, Korea (진해만 특별관리해역의 대형저서동물의 시공간 분포)

  • Seo, Jin-Young;Lim, Hyun-Sig;Choi, Jin-Woo
    • Ocean and Polar Research
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    • v.37 no.4
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    • pp.295-315
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    • 2015
  • In order to determine the spatio-temporal distribution of macrobenthic faunal communities in Jinhae Bay, quantitative faunal samples were collected seasonally at 23 sites in Jinhae Bay from February, 2011 to November, 2012. Sediment facies were found to be mud except for those at Chilcheon-do near Geoje Island. Mean values of TOC (%) ranged between 1.3 and 3.6%, and these are the highest values recorded excluding special management areas in Korea. Hypoxia occurred every summer in the whole areas of Jinhae Bay except around Geoje Island in the bay mouth. Due to the summer hypoxia, species richness, density and biomass also declined during the summer in Jinhae Bay. Opportunistic species such as Paraprionospio patiens, Sigambra bassi, Nectoneanthes oxypoda and Theora fragilis occurred as the dominant species before and after the hypoxia. However, Capitella capitata appeared as a dominant species only during the winter-spring season every year. From cluster analysis, Jinhae Bay could be divided into two sites groups: one group occupied the normoxic zone and the other one located in the hypoxic zone.