• Title/Summary/Keyword: mountain city

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Tropical Night (Nocturnal Thermal High) in the Mountainous Coastal City

  • Choi, Hyo
    • Journal of Environmental Science International
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    • v.13 no.11
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    • pp.965-985
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    • 2004
  • The investigation of driving mechanism for the formation of tropical night in the coastal region, defined as persistent high air temperature over than 25$^{\circ}C$ at night was carried out from August 14 through 15, 1995. Convective boundary layer (CBL) of a 1 km depth with big turbulent vertical diffusion coefficients is developed over the ground surface of the inland basin in the west of the mountain and near the top of the mountain, while a depth of thermal internal boundary layer (TIBL) like CBL shrunken by relatively cool sea breeze starting at 100 km off the eastern sea is less than 150 m from the coast along the eastern slope of the mountain. The TIBL extends up to the height of 1500 m parallel to upslope wind combined with valley wind and easterly sea breeze from the sea. As sensible heat flux convergences between the surface and lower atmosphere both at the top of mountain and the inland coast are much greater than on the coastal sea, sensible heat flux should be accumulated inside both the TIBL and the CBL near the mountain top and then, accumulated sensible heat flux under the influence of sea breeze circulation combined with easterly sea breeze from sea to inland and uplifted valley wind from inland to the mountain top returning down toward the eastern coastal sea surface should be transported into the coast, resulting in high air temperatures near the coastal inland. Under nighttime cooling of ground surface after sunset, mountain wind causes the daytime existed westerly wind to be an intensified westerly downslope wind and land breeze further induces it to be strong offshore wind. No sensible heat flux divergence or very small flux divergence occurs in the coast, but the flux divergences are much greater on the top of the mountain and along its eastern slope than on the coastal inland and sea surfaces. Thus, less cooling down of the coastal surface than the mountain surface and sensible heat transfer from warm pool over the coast into the coastal surface produce nocturnal high air temperature on the coastal inland surfaces, which is not much changed from daytime ones, resulting in the persistence of tropical night (nocturnal thermal high) until the early in the morning.

Geology and Landscape of Mt. Mudeung Province Park, Korea (무등산 도립공원의 지질과 경관)

  • Ahn, Kun-Sang
    • The Journal of the Petrological Society of Korea
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    • v.19 no.2
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    • pp.109-121
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    • 2010
  • Mt. Mudeung is located in Gwangju city, Damyang-Gun, Hwasun-Gun and its round form give us the mood of soft and rich. Its location is $126^{\circ}06'-127^{\circ}01'E$ and $35^{\circ}06'-35^{\circ}10'N$ and its highest peak is Cheonwang-bong with the height of 1,187 m. The Gwangju city is located in the West of Mt. Mudeng and the mountain range with a small basin in its East. The pavilion such as the Soswaewon, Songganjeong, Sigyongjeong are distributed along the stream in the north of Mt. Mudeung. The mountain is formed from the volcanic activity, Gwangju cauldron during the Cretaceous. The top part of Mt. Mudeung is composed of dark gray quartz-andesite and its K-Ar whole rock age is $48.1{\pm}1.7Ma$. The composition of the north area, where the Wonhyosa temple is located, is micrographic granite, whereas the composition of south area is rhyolite mainly. The main ridge of Mt. Mudeung runs from North, starting from the Bukbong, to south, passing Cheonwangbong, Jangbuljae and ending Anyangsan. Geologic feature of the mountain includes volcanic landform, mountaineous landform, and stream landform. The Seosukdae, Ipseokdae, Gyubongam, which are main ridges and formed from volcanic activity, are composed of mainly columnar joint. Saeinbong and Majipbong in the south-west are composed of mainly cliff and dome. The typical erosion landform of the mountain has three different types of the weathering-cave, each of which reflect the property of the original rock. Four different area of wide block stream, they makes the geological feature of spring-water, though its scale is small compared to that of water fall.

A Study on the Residents' Consciousness for Park and Green Space in the City of Daejeon (대전시 공원녹지에 대한 주민의식 조사)

  • Lee, Shi-Young;Shim, Joon-Young
    • The Journal of Natural Sciences
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    • v.18 no.1
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    • pp.65-76
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    • 2007
  • The purpose of this study is to examine residents' consciousness for urban parks and green spaces in the city of Daejeon. This work enables us to find new implementation factors to increase resident's satisfaction of urban parks and green spaces. This study surveyed 1005 residents from 80dongs(neighborhoods), of 5 Gu(districts) districts in Daejeon. The survey was conducted with a structurally organized questionnaire and objective materials. The data collected from participants of the survey were summarized as follows. Daejeon residents want more natural parks and neighborhood parks than other urban facilities as recreation facilities. The favorite places in which Daejeon residents visit are Bomun Mountain, Gap River, Geajock Mountain, and Yudeon River, in order. In landscape scenery of Daejeon, residents prefer Daedeck research complex area than others and they felt that urban landscape scenery is more improved than 5 years ago. Also they want to increase the area of park and green space about 4times more than present. The result shows that the importance index of park and green space is 8.7 and the satisfaction index is 5.42. These results suggests that the demand by residents for urban park and green spaces will improve as the urban structure is improved.

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A Study on the value decision and the application method of USLE factors for the soil loss estimation in the large scale site development area using GIS-In the Case of BuJu Mountain in MokPo City- (GIS를 이용한 대규모 단지 개발지의 토양유실량 추정을 위한 USLE의 인지값 결정과 적용 방법에 관한 연구-목포시 부주산을 대상으로-)

  • 우창호;황국웅
    • Journal of the Korean Institute of Landscape Architecture
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    • v.24 no.3
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    • pp.115-132
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    • 1996
  • The purpose of this study is to estimate the soil loss amount with Geographic Information System according to the land use change of Buju mountain area in Mokpo city. To estimate the soil loss, Universal Soil Loss Equation which is the most proper technique to predict soil loss in this site condition is adopted and IDRISI, a raster GIS software, is used. GIS application with USLE is very efficient to estimate soil loss accurately and fastly. In order to decide value and to find application method of USLE factors, we used existing rainfall erosion index, soil erodibility analysis, slope length, slope steepness, vegetation management and practices, which are rated by GIS through the analysis of various studies related USLE. The result of this study was compared with the previous other researches to verify our method of constructing numerical data of USLE's factors. The result of verification of our way showed significance for the soil loss in forest area. But the result of verification for the soil loss in forest area. But the result of verification for the soil loss of cultivated area showed some errors. It seems that this result was due to local variation of topographical map.

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Strategies to Build Ecological Networks in Consideration of Life-Zones in Cheongju City Using GIS (GIS를 활용한 청주시 생활권 생태네트워크 구축 방안)

  • Ban, Yong Un;Jeong, Ji-Hyeong;Woo, Hye-Mi;Baek, Jong In
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.12 no.4
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    • pp.1-10
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    • 2009
  • This study has intended to build ecological networks in consideration of life-zones inside Cheongju city through biotope grade, GIS network analysis etc. This study consisted of following three steps. First, we selected core districts and core spot districts using land use patten and biotope grade. The core district included the first grade of biotope and forest land. The core district consisted of two sectors : east axis core, Uam mountain; west axis core, Bumo mountain. The core spot district included the first grade of biotope. The core spot districts consisted of two sectors : north axis base core, Myongshim park; south axis base core, Guryong park. Second, the base district included the second grade of biotope and park and school. We used buffering analysis within 500m of the base district and selected the new base district. Third, we connected core districts and base core districts using least cost analysis of GIS. Thus we built comprehensive ecological networks in consideration of life-zones through GIS.

A Study on Establishing Optimum Scale of Sediment Basin for Preventing the Outflow of Sediment - In the case of Buju Mountain in Mokpo city, Korea - (토사유출 방지용 침사지 적정규모 설정방안에 관한 연구 -목포시 부주산을 사례로-)

  • 우창호;황국웅
    • Journal of the Korean Institute of Landscape Architecture
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    • v.26 no.4
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    • pp.59-69
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    • 1999
  • This study examines the existing theories related to detention basin and embodies the calculation process of sediment basin. It investigated the scale of sediment basin by actual measurement at Buju Mountain, Mokpo city which causes the environmental problems like erosion and outflow of sediment due to the excessive development, finds the problems of existing sediment basin by applying and analyzing the physical factors which affect the execution of sediment basin using GIS as the method establishing the scale of sediment basin embodied in this study and then suggests the oteimum scale. Comparing the surface area of the existing sediment basin and of the required one, all of the surface areas of the existing sediment basins were smaller than those of the required one. Therefore, it can be expected that the trap efficient of sediment will be declined. The required one. Therefore, it can be expected that the trap efficient of sediment will be declined. The required minimum depth was fully satisfied, but it is analyzed that the volume of sediment basin will affect the neighboring environment because it can not accomodate the inflow discharge volume except sediment basin C. It is consistent with the actual situation which causes a serious environmental problem due to the overflow of sediment basin during the heavy storm event except sediment basin C and also it verifies the validity of calculation process of establishing optimum sediment basin suggested in this study.

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A secondary development based on the Hoek-Brown criterion for rapid numerical simulation prediction of mountainous tunnels in China

  • Jian Zhou;Xinan Yang;Zhi Ding
    • Geomechanics and Engineering
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    • v.34 no.1
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    • pp.69-86
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    • 2023
  • To overcome the dilemma of the [BQ] method's inability to predict mountain tunnel support loads, this study is based on the Hoek-Brown criterion and previous results to obtain the connection equations from GSI scores to each parameter of the Hoek-Brown criterion and the link between the [BQ] scores and the GSI system. The equations were embedded in the Hoek-Brown criterion of FLAC6.0 software to obtain tunnel construction forecasts without destroying the in-situ stratigraphy. The feasibility of the secondary development of the Hoek-Brown criterion was verified through comparative analysis with field engineering measurements. If GSI > 45 with a confining pressure of less than 10 MPa, GSI has little effect on the critical softening factor while we should pay attention to the parameter of confining pressure when GSI < 45. The design values for each parameter are closer to the FLAC3D simulation results and the secondary development of the Hoek-Brown criterion meets the design objectives. If the Class V surrounding rock is thinned with shotcrete or the secondary lining is installed earlier, the secondary lining may act as the main load-bearing structure. The study may provide ideas for rapid prediction of mountainous tunnels in China.

An Analysis of the Visual Characteristics and Preference Factors of an Urban River - With a case of Gapcheon in Daejeon Metropolitan City - (도시하천의 시각적 특성 및 선호요인 분석 -대전광역시 갑천을 중심으로-)

  • Jeong, Dae-Young;Hur, Seong Soo;Shin, Un Dong
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.10 no.3
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    • pp.14-24
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    • 2007
  • The purpose of this study was to investigate how the landscape characteristics and the physical factors of landscape would affect the preference for the Gapcheon in Daejeon Metropolitan City. The Gapcheon was divided in three sections of the outskirts, Expopark areas, and residential complexes. After selecting seven landscape points where the sections could be expressed best, photographs were taken both in the upstream and downstream direction. The questionnaire used to evaluate the river's landscape included 20 items of adverbs that described the form of the river and one item to rate the overall preference. By analyzing the 14 pictures taken, the occupancy rates of the landscape elements in terms of the sky, river, vegetation of the river, mountain, and artificial structures. Image factor analysis was conducted for each of the sections in order to analyze the landscape characteristics of the Gapcheon, and then regression analysis was conducted in order to analyze the relationships among the physical factors influencing the preference of the landscapes. The results were as follows : Factors that compose the visual characters of urban river were classified be the aesthetic factor, the emotional factor and the situation factor. These 3 factors showed a 65.8% total variance. The river landscape with the biggest preference was the one from the Daedeok Grand Bridge as the occupancy area of the mountain, sky, and river was large and distributed evenly and the vegetation of the river was in a good harmony with the surroundings. After carrying out regression analysis to examine the relationships between the visual preference of Gapcheon and the physical factors of landscape(the sky, river, vegetation of the river, mountain, and artificial structure), the following regressions model was made : PRE=5.906+0.017(river)-0.053(artificial structure)-0.060(vegetation of the river) (R-square=0.48).

Diurnal Variation of Atomospheric Pollutant Concentrations Affected by Development of Windstorms along the Lee Side of Coastal Mountain Area

  • Choi, Hyo
    • International Union of Geodesy and Geophysics Korean Journal of Geophysical Research
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    • v.24 no.1
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    • pp.29-45
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    • 1996
  • Before (March 26, 1994) or after the occurrence of a downslope windstorm (March 29), the NO, $NO_2$, and $SO_2$ at the ground level of Kangnung city were monitored with high concentrations in the afternoon, due to a large amount of gases emitted from combustion of motor vehicle and heating apparatus, especially near 1600-1800 LST and 2000-2100 LST, but at night, they had low concentrations, resulting from small consumptions of vehicle and heating fuels. When both moderate westerly synoptic-scale winds flow over Mt. Taegwallyang and easterly meso-scale sea breeze during the day, atmospheric pollutants should be trapped by two different wind systems, resulting in higher concentration at Kangnung city in the afternoon. At night, the association of westerly synoptic wind and land breeze can produce relatively strong winds and the dissipation by the winds cause these low concentrations to lower and lower, as nightime goes on. From March 27 through 28, an enforced localized windstorm could be produced along the lee side of the mountain near Kangnung, generating westerly internal gravity waves with hydraulic jump motions. Sea breeze toward inland appartantly confines to the bottom of the eastern side of the mountain, due to the interruption of eastward violent internal gravity waves. As the windstorm moves down toward the ground, an encountering point of two opposite winds approaches Kangnung, and a great amount of NO and $NO_2$ were removed by the strong surface winds. Thus, their maximum concentrations are found to be near 18 and 20 LST, 17 and 21 LST. In the nighttime, the more developed storm should produce very strong surface winds and the NO and $NO_2$ could be easily dissipated into other place. The $SO_2$ concentration had no maximum value, that is, almost constant one all day long, due to its removal by the strong surface winds. Especially, the CO concentrations were slightly lower during the strom period than both before or after the strom, but they were nearly constant without much changes during the during the daytime and nighttime.

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