• Title/Summary/Keyword: 완만한 경사

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Evaluation of GIS-based Soil Loss Amount in Considering Basin Characteristics (유역특성을 고려한 GIS 기반 토양침식량 평가)

  • Guak Dong-Wook;Cho Gi-Sung
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.24 no.1
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    • pp.89-97
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    • 2006
  • Soil erosion has caused serious environmental problems which threaten the foundation of natural resources. In this paper, we chose RUSLE erosion model, which could be connected easily with GSIS and available generally in mid-scale watershed among soil erosion models, and extracted factors entered model by using GSIS spatial analysis method. First, this study used GIS database as soil map, DEM, land cover map and rainfall data of typhoon Memi (2003) to analyze soil loss amount of Dam basin. To analyze the changes of soil loss in considering basin characteristics as up-, mid- and downstream, this study calculated soil erodibility factor (K), topographic factors (LS), and cover management factor (C). As a result of analysis, K and LS factors of upstream showed much higher than those of downstream because of the high ratio of forest. But C factor of downstream showed much higher than that of upstream because of the high ratio of agricultural area. As a result of analysis of soil loss, unit soil loss of upstream is 4.3 times than soil loss of downstream. Therefore, the establishment of countermeasures for upstream is more efficient to reduce soil loss.

Extracting Ground Information from Airborne Laser Scanning Data based on Mean Filtering Method (평균필터기반 항공레이저측량 자료의 지면정보 추출기법)

  • Choi, Yun-Woong;Lee, Geun-Sang;Chae, Hyo-Sok;Cho, Gi-Sung
    • Journal of the Korean Association of Geographic Information Studies
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    • v.8 no.4
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    • pp.61-70
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    • 2005
  • Airborne laser scanning system needs preprocessing which removes some objects such as buildings from the raw DSM data to construct DEM in building area because the laser pulse can't penetrate into the buildings. This study applied the mean filtering method which has various size filter to the DSM data constructed by airborne laser scanning system and decided the optimal filter size as $39{\times}39$ by analyzing the standard deviation change ratio. Also, this study could get the ${\pm}0.065m$ standard error by comparing the optimal filtering DEM and DSM raw data of airborne laser scanning. Therefore, it could know that the mean filtering method, which is presented in this study, is very effective to extract DEM in the urban area which has a low relief.

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Analysis of Characteristic and Disparate Image of Urban Space - Focused on Busan Metropolitan City - (도시공간의 특성 및 이질적 이미지 분석 - 부산광역시를 대상으로 -)

  • Hong, Ji Su;Kim, Jong Gu
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.37 no.6
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    • pp.1077-1085
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    • 2017
  • Urban space is a place that shows the behavior, experience and lifestyle of residents. Also by the combination of local attributes and assets, creating a space that reflects the unique image of the city. For the development of the city, it is important to actively reflect the identity of the space created by the difference of each space. In this study, we focused on the disparate of space and found the characteristics of urban space. And psychological factors on disparate images of the spatial analysis. As a result, 14 spatial image characteristics of Busan showed difference. In terms of dimensions, it could be classified as an natural, artificial, dynamic, static images. Also, the preference cluster of individuals showed a positive response in naturalness, openness, gentle slope and static space.

Analysis of the Watershed Information and Pollutants Load using GIS in Mankyung and Dongjin Rivers (지리정보체계를 이용한 만경강.동진강의 유역정보 및 오염부하량 분석)

  • Ko, Jae-Won;Jeong, Shin-Taek;Kim, Chul;Cho, Hong-Yeon
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.13 no.3
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    • pp.237-244
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    • 2001
  • The watershed information of the Mankyung River and Dongjin River is obtained and analysed using the GIS tool. The informations i.e., digital map, land use, point sources, weather station, water quality measurement station, and pollutants load unit are managed by DB system. The slope, rainfall, and generated pollutants loads of COD, TN and TP which are the input data of the rainfall-runoff-pollutants load model are estimated. From the analysis of the collected and generated data, the almost watershed area is composed of agricultural lands except the upstream regions. The population and industrial area are densely located in Cheonju City and Iksan City, whereas the farming areas are widely distributed.

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Facies and sequence analysis on the Lower Ordovician Mungok Formation (전기 오오도비스기 문곡층의 시퀀스 및 상 분석)

  • Choi Yong Seok;Lee Yong Il
    • The Korean Journal of Petroleum Geology
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    • v.9 no.1_2 s.10
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    • pp.1-15
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    • 2001
  • Hierarchically controlled sequence stratigraphic analysis shows that the Lower Ordovician mixed carbonatesiliciclastic Mungok Formation, Korea consists of three depositional sequences: T1, T2, and T3 in ascending order. Sequence boundaries are generally marked by abrupt transition from coarse-grained shallow-water carbonates to finegrained deeper-water carbonates mixed with fine-grained siliciclastics, and show indication of subaerial exposure such as karstification. Within this sequence stratigraphic framework, facies characteristics indicate that the Mungok sequences were mostly deposited on a subtidal ramp without slope break. The Mungok ramp had been under the influence of frequent tropical storm activity during deposition. The difference in lithology of tempestites seems to have been controlled by the nature of substrates and by proximality. High-frequency cycles consist of upward-shallowing facies successions. Cycles of shallow-water and basinal deposits are not well represented, probably due to cycle amalgamation. Cycle stacking patterns do not show a consistent thickness change that is usually associated with a large-scale sea-level change probably because of unfilled accommodation space.

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Groundwater Intake System Using Wind Energy in Jeju Island (제주지역의 풍력에너지를 이용한 지하수 취수시스템)

  • Kim, Seong-Beom;Go, Jin-Seok;Yeo, Un-Gi;Lee, Seung-Yun;Ji, Hong-Gi
    • Proceedings of the Korea Water Resources Association Conference
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    • 2006.05a
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    • pp.1885-1889
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    • 2006
  • 제주지역은 대륙과 해양을 연결하는 요충지로서 한라산을 중심으로 동서사면은 $3{\sim}5^{\circ}$의 완만한 경사를 이루고 있다. 연평균 강우량은 1,975mm로서 국내 최다우 지역이나 제주도의 지질 특성상 도내 대부분의 지역이 투수성이 높은 다공질 현무암으로 구성되어 있는 관계로 지표수의 발달이 미약한 반면 지하수가 풍부하게 부존되어 있으며 기저지하수, 준 기저지하수, 상위지하수, 기반암지하수로 이루어져 있다. 최근 우리나라의 교토의정서 비준으로 인한 온실가스 감축이 불가피함에 따라 대체 재생가능한 에너지를 이용한 풍력발전시대가 도래하고 있으며, 제주 행원풍력발전단지에 설치된 총 15기 발전장치의 현실성과 경제성 입증을 통해 제주지역의 풍력에너지를 이용한 지하수 취수시스템을 제안하였다. 본 연구는 제주, 고산, 서귀포, 성산포지역에 대한 제주지방기상청 연평균 풍속자료$(2004{\sim}2005)$를 통하여 대상지역내 적용 가능한 로터(Roter), 나셀(Nacelle), 타워(Tower), 발전기를 포함한 발전장치를 선정하였으며, 공기역학적(Aerodynamic)특성에서 전기에너지로 변환한 풍력에너지를 지하수 취수시스템으로 적용하기까지의 전력공급절차를 도출하였다. 또한 생산되어진 풍력에너지 용량에 적용 가능한 수중.육상모터펌프를 산정하여 '제주도 지하수개발.이용시설 설치 및 관리기준(2004)'에서 제시한 구조도를 바탕으로 대상지역내 지하수위를 고려한 지하수 취수시스템을 도시하였다. 제주도는 지형 및 지질적인 특성상 수자원을 지하수에 의존할 수밖에 없는 특수한 지역이므로 2002년말 통계를 살펴보면 생활용, 공업용, 농업용으로 각각 57만$m^2$, 11만$m^2$, 56만$m^2$를 포함한 1일 최대 124만$m^2$의 지하수를 사용하고 있다. 따라서 풍력에너지를 이용한 지하수 취수시스템을 도입하여 재생가능한 에너지이용 효과와 세계인이 공감하는 청정한 관광자원으로 활용 가능할 것이라 판단된다.

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Effect of Silty Soil Content on Shear Behavior of Sandy Soil (사질토의 전단거동에 실트 함량이 미치는 영향)

  • Yu, Jeongseok;Ahn, Kwangkuk;Kang, Hongsig
    • Journal of the Korean GEO-environmental Society
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    • v.21 no.11
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    • pp.21-26
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    • 2020
  • Natural soil is composed of particles of various sizes, and the shear behavior which is a kind of mechanical behavior of the soil is affected by the particle size distribution. In addition, since the natural soil contains a large mixture of coarse and fine grained soil, it is difficult to clearly understand the shear behavior of the soil. Therefore, a ring shear test was conducted on sandy soils that has various particle size distribution in order to identify the effect of the distribution on shear characteristics of soils. At this time, sand and silt were used for coarse and fine grained soils, respectively, to make sandy soils by changing the silt content. Also the water was supplied during the test to confirm shear characteristics of sandy soils with various particle size distributions. The result shows that the shear strength increases as the silt content increases, and the strength decreases as the silt content increases over the sand. Besides, residual shear strength gradually decreases because of the silt content when the water is supplied.

A Study on Taehwa River Red Tide Solution through Stream Flow (유수소통을 통한 태화강 적조해결 방안 연구)

  • Cho, Hong-Je;Yoon, Sung-Kyu
    • Journal of Wetlands Research
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    • v.13 no.2
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    • pp.363-375
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    • 2011
  • Recently, Water quiality of urban river largely have gotten better by virtue of sewer pipe laying and sewage treatment plants construction. or the various contaminants which is flowed in into river have generated underwater ecosystem disturbance and red tide by lack of sewage and waste water disposal facilities. With tidal river, taehwa river of ulsan metropolitan city has large river width and gradual stream bed gradient at the dry and storage period. Moreover, the flow is paralyzed due to the bridge pier protection work, consist of the mat foundation which is about 1.2km from two bridge and the contaminant is accumulated. it is caused by of the red tide generated from the several years or it activates. In this study, When flow area is largest by changing independent footing of bridge pier of two bridges and using RMA2 model, we hydraulically analyzed a variable breadth of velocity and discharge. Consequently, flow rate increased the maximum 103%, discharge was exposed to increase the maximum 61%. Directly this cannot extinguish the red tide but suppresses the red tide occurrence or can reduce. And it is determined to prevent the depositioning of the contaminant and can control fundamentally the red tide occurrence cause.

Effect of Estimation for Time of Concentration on the Design Flood (홍수도달시간 산정방법이 설계홍수량에 미치는 영향)

  • Kwon, Ki Dae;Lee, Jun Ho;Kang, Mi Jeong;Jee, Hong Kee
    • Journal of Wetlands Research
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    • v.16 no.1
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    • pp.125-137
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    • 2014
  • In this study, that the Kraven(II) empirical formula, the existing method to estimate the time of concentration in river basin, does not reflect the characteristics of relevant basin as it presents 3 stream velocities by section of slope was verified, and the time of concentration for the actual average stream velocity considering the characteristics of the basin was compared and analyzed by applying the continuous Kraven empirical formula, which was suggested recently by 'Design Flood Estimation Guide Line, 2012, Ministry of Land, Transport and Maritime Affairs' complementing the stream velocities for the easy slope and the steep slope, to the Donghwa-Cheon, the medium size river and the modality of changes in hydrograph was examined, For the Maeho-Cheon, Wuksu-Cheon and Geumpo-Cheon, the flood runoff simulation results according to the time of concentration application empirical formula considering the characteristics of relevant basin were compared and analyzed and following conclusions were able to obtain.

The characteristics of folk house related to climate in Cheju island (기후 특성과 관련된 제주도의 민가 경관)

  • Kim, Ki-Deog;Lee, Seung-Ho
    • Journal of the Korean association of regional geographers
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    • v.7 no.3
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    • pp.29-43
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    • 2001
  • This paper examined characteristics of folk houses related to climate in Cheju island using climate data, documents and field survey data. Precipitation and humidity affect characteristics of folk houses in the southern parts of the island during summer while in winter, northern parts are mainly affected by wind. Chuck-gub has been shown through all over Cheju island due to the characteristics of precipitation. Jaechangmoon exists in southern parts of the island and these parts are experienced high humidity in summer The double-row room houses, the low eaves, gentle slop roof and stone wall are distributed through Cheju island and is related to wind. The double door is common in the northern parts because of strong winter monsoon, and Yimoonkan exists in the coastal area of the northern parts. Outer wall, Pung-Che and Gorangche are affected by winter monsoon and abundant precipitation. Gorangche has shown through both the northern parts and southeastern parts. Folk houses in the southern parts are more open than in northern parts. Folk houses in the northern parts are divided into the coastal type and the piedmont type. In the southern parts, they are subdivided the eastern type and the western type by the appearance of Gorangche.

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