• 제목/요약/키워드: topography of land

검색결과 394건 처리시간 0.031초

APPLICATION OF LIKELIHOOD RATIO A MODEL FOR LANDSLIDE SUSCEPTIBILITY MAPPING USING GIS AT JANGHUNG, KOREA

  • Choi, Jae-Won;Lee, Saro;Yu, Young-Tae
    • 한국GIS학회:학술대회논문집
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    • 한국GIS학회 2003년도 공동 춘계학술대회 논문집
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    • pp.63-63
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    • 2003
  • The aim of this study is to apply and verify of Bayesian probability model, the likelihood ratio and statistical model, at Janghung, Korea, using a Geographic Information System (GIS). Landslide locations were identified in the study area from interpretation of IRS satellite images, field surveys, and maps of the topography, soil type, forest cover, geology and land use were constructed to spatial database. The factors that influence landslide occurrence, such as slope, aspect and curvature of topography were calculated from the topographic database. Texture, material, drainage and effective soil thickness were extracted from the soil database, and type, diameter and density of forest were extracted from the forest database. Land use was classified from the Landsat TM image satellite image. As each factor's ratings, the likelihood ratio coefficient were overlaid for landslide susceptibility mapping, Then the landslide susceptibility map was verified and compared using the existing landslide location. The results can be used to reduce hazards associated with landslides management and to plan land use and construction.

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한반도 지형이 대상수렴운의 생성에 미치는 영향에 관한 WRF 민감도 실험 (WRF Sensitivity Experiments on the Formation of the Convergent Cloud Band in Relation to the Orographic Effect of the Korean Peninsula)

  • 김유진;이재규
    • 대기
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    • 제25권1호
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    • pp.51-66
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    • 2015
  • This study was conducted to perform various sensitivity experiments using WRF (Weather Research and Forecasting) model in order to determine the effects of terrains of the Korean Peninsula and the land-sea thermal contrast on the formation and development of the convergent cloud band for the cases of 1 February 2012. The sensitivity experiments consist of the following five ones: CNTL experiment (control experiment), and TMBT experiment, BDMT experiment and ALL experiment that set the terrain altitude of Taeback Mountains and Northern mountain complex as zero, respectively, and the altitude of the above-mentioned two mountains as zero, and LANDSEA experiment that set to change the Korean Peninsula into sea in order to find out the land-sea thermal contrast effect. These experiment results showed that a cold air current stemming from the Siberian high pressure met the group of northern mountains with high topography altitude and was separated into two air currents. These two separated air currents met each other again on the Middle and Northern East Sea, downstream of the group of northern mountains and converged finally, creating the convergent cloud band. And these experiments suggested that the convergent cloud band located on the Middle and Northern East Sea, and the cloud band lying on the southern East sea to the coastal waters of the Japanese Island facing the East Sea, were generated and developed by different dynamical mechanisms. Also it was found that the topography of Taeback Mountains created a warm air advection region due to temperature rise by adiabatic compression near the coastal waters of Yeongdong Region, downstream of the mountains. In conclusion, these experiment results clearly showed that the most essential factor having an effect on the generation and development of the convergent cloud band was the topography effect of the northern mountain complex, and that the land-sea thermal contrast effect was insignificant.

다중시기 위성영상을 이용한 새만금 방조제 내측 해수면에 의한 심포항 연안의 간석지 지형 변화 탐지 (Monitoring of the Changes of Tidal Land at Simpo Coast with Sea Surface inside Saemangeum Embankment Using Multi-temporal Satellite Image)

  • 이홍로;이재봉
    • 한국지리정보학회지
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    • 제8권1호
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    • pp.13-22
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    • 2005
  • 본 논문은 무감독 ISODATA 기법을 이용하여 Landsat TM 위성영상에 기반한 새만금 간석지의 지형을 분류하고, 이 분류된 지형의 시공간적 변화를 분석하고자 한다. 각각의 퇴적 지형은 새만금 방조제 공사 진행에 따른 상이한 특성을 나타내며, 퇴적 변화와 분포를 입증한다. Landsat TM 7개의 band 중에서 밴드 4가 간석지와 해수면의 구분, 그리고 밴드 5는 간석지에 대한 세부적인 지형의 분류에 이용한다. 각 지역의 지형적 특성을 구분함으로써 간석지의 지형변화에 따른 검토는 간척 계획수립과 간척된 이후의 토지 이용에 매우 유용할 것으로 사료된다.

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원격탐사자료를 이용한 인공구조물 건설에 의한 군산 유부도 조간대의 지형변화 및 표면특성에 관한 연구 (Research of Topography Changes by Artificial Structures and Scattering Mechanism in Yoobu-Do Inter-tidal Flat Using Remote Sensing Data)

  • ;김덕진;김승희
    • 대한원격탐사학회지
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    • 제29권1호
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    • pp.57-68
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    • 2013
  • 20세기 후반부터 유부도 주위에서 하구언 축조 등 비교적 큰 규모의 간척사업들이 진행되었다. 이러한 간척사업의 시작으로 인공구조물들이 연안에 축조됨에 따라 주변 해역의 해류, 조위 및 조류의 변화를 야기하여 퇴적 및 침식으로 인한 연안지형의 변화가 예상된다. 따라서 이 연구에서는 유부도 조간대를 포함하는 Landsat TM/ETM+자료를 1998년부터 2012년까지 획득한 후 waterline 기법을 적용하여 인공구조물 축조에 의한 지형변화를 탐지하였다. 그 결과 유부도의 동쪽, 북동쪽, 서쪽 조간대에서 주로 퇴적이 일어났으며 그 면적이 약 4.5 $km^2$ 이상 되었다. 한편, RADARSAT-2의 완전편파 SAR자료에 Freeman-Durden decomposition을 적용하여 퇴적이 뚜렷이 일어난 지역에 대한 산란특성을 분석하였다. 그 결과 동쪽 퇴적지역은 서쪽 및 북동쪽의 퇴적지역과는 다른 산란특징이 관찰되었으며, 이는 퇴적환경의 차이로 인해 다른 종류의 퇴적물이 퇴적되어 발생한 것으로 여겨진다.

종관 환경 변화에 따른 아격자 산악모수화와 고해상도 지면 자료가 WRF 모델의 바람장 모의에 미치는 영향 (Effects of the Subgrid-Scale Orography Parameterization and High-Resolution Surface Data on the Simulated Wind Fields in the WRF Model under the Different Synoptic-Scale Environment)

  • 이현지;김기병;이준홍;신혜윰;장은철;임종명;임교선
    • 대기
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    • 제32권2호
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    • pp.103-118
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    • 2022
  • This study evaluates the simulated meteorological fields with a particular focus on the low-level wind, which plays an important role in air pollutants dispersion, under the varying synoptic environment. Additionally, the effects of subgrid-scale orography parameterization and improved topography/land-use data on the simulated low-level wind is investigated. The WRF model version 4.1.3 is utilized to simulate two cases that were affected by different synoptic environments. One case from 2 to 6 April 2012 presents the substantial low-level wind speed over the Korean peninsula where the synoptic environment is characterized by the baroclinic instability. The other case from 14 to 18 April 2012 presents the relatively weak low-level wind speed and distinct diurnal cycle of low-level meteorological fields. The control simulations of both cases represent the systematic overestimation of the low-level wind speed. The positive bias for the case under the baroclinic instability is considerably alleviated by applying the subgrid-scale orography parameterization. However, the improvement of wind speed for the other case showing relatively weak low-level wind speed is not significant. Applying the high-resolution topography and land-use data also improves the simulated wind speed by reducing the positive bias. Our analysis shows that the increased roughness length in the high-resolution topography and land-use data is the key contributor that reduces the simulated wind speed. The simulated wind direction is also improved with the high-resolution data for both cases. Overall, our study indicates that wind forecasts can be improved through the application of the subgrid-scale orography parameterization and high-resolution topography/land-use data.

Variation of Paleotopography around the Ssangsujeong Pavilion Area in Gongsanseong Fortress using GIS and 3D Geospatial Information

  • Lee, Chan Hee;Park, Jun Hyoung
    • 보존과학회지
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    • 제38권4호
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    • pp.347-359
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    • 2022
  • Gongsanseong Fortress was registered of a World Heritage Site in 2015 as a representative cultural heritage from the Woongjin Baekje period, and it has been used throughout the entire period from Baekje Kingdom to the Joseon Dynasty. Within Gongsanseong Fortress, the area around Ssangsujeong is presumed the site of royal palace of the Woongjin Baekje. Also, the excavated culture layers of the Baekje Kingdom, the Unified Silla period, and the Joseon Dynasty were confirmed. In this study, paleotopography was modeled by digitally converting the elevation data obtained through surveying the excavation process, and the use of the topography in the Ssangsujeong area was considered by examining the variations in the topography according to the periods. As a result, the topography of the slope around the peak changed by periods, and the topography did not change on the flat land. The topography between the Baekje Kingdom and the Unified Silla period appeared to be almost identical, and it seems that the space of the Baekje period was maintained as it is. Also, during the Joseon Dynasty, it is confirmed that flat surfaces in the previous period were used. However, sediments on the slopes flowed down, reducing the area of the flatland, and architectural techniques that could utilize the natural topography of the changed slope were applied to interpret it as having a different topography from the previous period. In order to model and interpret the paleotopography, excavation data, geological and topographic analysis, and digital data must be secured. It is expected that location conditions and ancient human life can be identified if the analysis technique in the study is applied to other archaeological sites in the future.

농림위성의 목표 수직기하 정확도 결정을 위한 남한 지역 수치표고모델 상대 오차 분석 (The Relative Height Error Analysis of Digital Elevation Model on South Korea to Determine the TargetVertical Accuracy of CAS500-4)

  • 백원경;유진우;윤영웅;정형섭;임중빈
    • 대한원격탐사학회지
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    • 제37권5_1호
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    • pp.1043-1059
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    • 2021
  • 식량자원의 확보와 환경생태계에 매우 중요한 요소인 산림과 농경지는 정기적인 모니터링이 요구된다. 농림 위성 영상 자료는 우리나라의 기존 산림 및 농경지 모니터링 방법의 보완재로 효과적으로 활용될 것으로 예상되고 있다. 농림위성의 발사 이전에 사전연구로써 목표 수직기하정확도 산정을 위해 수치표고모델 분석을 수행하였다. 특히 농림위성의 주요 관심 지역인 우리나라 산악지역과 농경지의 특성을 고려하여, 경사도와 식생에 따른 분석을 수행하였다. 공주, 제주 그리고 삼척 지역에 대하여 Shuttle radar topography mission digital elevation model과 Copernicus digital elevation model를 가을과 겨울에 촬영한 드론 LiDAR 수치표면모델 그리고 국토지리정보원 5 m 수치지형모델을 기준으로 평균 상대오차를 비교했다. 그 결과 Shuttle radar topography mission digital elevation model은 8.35, 8.19, 그리고 7.49 m의 상대오차를 나타냈으며, Copernicus digital elevation model는 각각 5.65, 6.73, 그리고 7.39 m의 상대 고도 오차를 나타냈다. 남한 전체에 대하여 Shuttle radar topography mission digital elevation model과 Copernicus digital elevation model를 국토지리정보원 5 m 수치지형모델을 기준으로 지형 경사에 따른 상대 고도 오차를 나타냈다. 그 결과 경사도 0°~5° 사이에서 Shuttle radar topography mission digital elevation model과 Copernicus digital elevation model의 상대 고도 오차는 각각 약 3.62와 2.52 m로 Shuttle radar topography mission digital elevation model의 오차가 더 큰 것으로 산출되었다. 하지만 경사도가 증가함에 따라 이러한 양상은 반전되어 경사도 35° 이상에서는 각각 10.16, 그리고 11.62 m 로 Copernicus digital elevation model의 상대오차가 더 크게 나타났다.

A Numerical Study on the Formation Mechanism of a Mesoscale Low during East-Asia Winter Monsoon

  • Koo, Hyun-Suk;Kim, Hae-Dong;Kang, Sung-Dae;Shin, Dong-Wook
    • 한국지구과학회지
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    • 제28권5호
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    • pp.613-619
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    • 2007
  • Mesoscale low is often observed over the downstream region of the East Sea (or, northwest coast off the Japan Islands) during East-Asia winter monsoon. The low system causes a heavy snowfall at the region. A series of numerical experiments were conducted with the aid of a regional model (MM5 ver. 3.5) to examine the formation mechanism of the mesoscale low. The following results were obtained: 1) A well-developed mesoscale low was simulated by the regional model under real topography, NCEP reanalysis, and OISST; 2) The mesoscale low was simulated under a zonally averaged SST without topography. This implies that the meridional gradient of SST is the main factor in the formation of a mesoscale low; 3) A thermal contrast ($>10^{\circ}C$) of land-sea and topography-induced disturbance served as the second important factor for the formation; 4) Paektu Mountain caused the surface wind to decelerate downstream, which created a more favorable environment for thermodynamic modification than that was found in a flat topography; and 5) The types of cumulus parameterizations did not affect the development of the mesoscale low.

국립공원 사유지 정책의 공간의사결정지원을 위한 생태자원성 평가 (Ecological Resource Assessment for Spatial Decision Support on Private land Policy inside National Parks, Korea)

  • 이관규
    • 한국환경복원기술학회지
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    • 제9권5호
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    • pp.41-49
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    • 2006
  • Private land within national parks has raised acute questions for impact assessment practitioners as to whether it is ecologically resourceful enough to be conserved or whether it should be removed from national parks and compensated accordingly. The purpose of this study is to provide a framework for spatial decision support through assessing ecological resource of private land within national parks. In order to assess the ecological resource, private land within national parks was analyzed and quantified based upon topography, flora and fauna. National parks, according to the ecological resource assessment, have been divided into three groups : the parks in need of careful attention for conservation; the parks needed to be retained as buffers, and; the parks that can be released to private land. According to the analysis, part of Mountain Joowang is the third-tier land that does not require conservation efforts. This case study intends to help policy-makers decide whether some private land within national parks can be released and, after the release, what should be done to prevent reckless development of the released land.

중규모 국지순환에서 이산화황의 농도예측에 관한 연구 (A Study on the Prediction of SO2 Concentration in local Circulation of Mesoscale)

  • 이화운;김유근;장은숙
    • 한국환경과학회지
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    • 제5권3호
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    • pp.277-284
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    • 1996
  • The Characteristics of atmospheric flow and dispersion of air pollutants in the mountainous coastal area were studied using two-dimensional model by the combination of land-sea breezes and transport. The pollutants emitted into the simulated wind field in considering with the mesoscale local circulations. The typical effects of land-sea breezes and tophography of coastal area on the dispersion are discussed in detail, and the model is proved as an useful tool to pridict real time pollutant transport by the results of application studies in Pusan, Korea where the urbanized coastal area with mountainous topography. It was found that sulfur dioxide ($SO_2$) are differently transported and concentrated as going inland by the influence of the sea breeze with topographic changes. Key words : land-sea breezes, sulfur dioxide, dispersion, coastal area.

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