• 한국방재학회:학술대회논문집
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• 2008.02a
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• pp.353-356
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• 2008

최근 대규모 산림재해로 인한 산림환경 훼손 및 산림 농가의 피해는 물론 산림생태계에도 나쁜 영향을 미치고 있으며 이는 사회적으로 매우 민감한 환경문제로서 국민의 주요 관심사가 되고 있다. 본 연구에서는 울진군 전체를 대상으로 GIS 및 RS 기법을 이용하여 다양한 산사태 관련 인자들을 추출 하여 이를 기반으로 GIS 중첩 및 가중치 분석을 통하여 울진군의 산사태 발생 가능 위험지역의 분포도를 작성하고자 한다.

• Journal of Korean Society of societal Security
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• v.2 no.2
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• pp.85-90
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• 2009

In recent days, climatic change cause abnormal weather all over the world and we have a great loss of life and property every year. In Korea, we suffer from landslide problem because large regions of Korea Peninsula are composed of mountain. In order to detect rapidly and to take follow-up measures of disaster, the remote sensing is being used actively as conventional field survey has many restrictions in accessibility because of more time and man power requirement. In additions interferometric SAR is one of the techniques that have our attention because it can provide many kinds of accurate surface information without restriction of atmospheric and ground conditions by using L-band. In this study, we aimed to monitor the displacement of mountain area in Kangwondo and this results will be used for detecting landslide. Also we build the web system for detecting and analyzing the landslide.

• Geophysics and Geophysical Exploration
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• v.21 no.3
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• pp.162-170
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• 2018

The purpose of this study is to understand the ground change of large scale mountainous region and to estimate the active weak zone using geophysical exploration (electrical resistivity and refraction seismic explorations) in large scale deep landslide area located in Wanjugun, Jeollabukdo. We also analyzed the characteristics of deep landslides occurred in metamorphic rocks region and confirmed the approximate scale. As a result of comparative analysis of N-value by standard penetration test (SPT), low resistivity anomaly, and tension crack identified from field investigation, a discontinuity in soil layer was estimated at 10 ~ 15 m below the surface. Based on this results, the distribution pattern of active weak zone was confirmed between the discontinuity in soil layer and estimation line of bedrock.

• Economic and Environmental Geology
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• v.34 no.4
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• pp.385-394
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• 2001

There are serious damage of people and properties every year due to landslides that are occurred by heavy rain. Because these phenomena repeat and the heavy rain is not an atmospheric anomaly, the counter plan becomes necessary. The study area, Ulsan, is one of the seven metropolitan, and largest cities of Korea and has many large facilities such as petrochemical complex and factories of automobile and shipbuilding. So it is necessary assess the landslide hazard potential. In the study. the three steps of landslide hazard assessment techniques such as susceptibility, possibility, and risk were performed to the study area using GIS. For the analyses, the topographic, geologic, soil, forest, meteorological, and population and facility spatial database were constructed. Landslide susceptibility representing how susceptible to a given area was assessed by overlay of the slope, aspect, curvature of topography from the topographic DB, type, material, drainage and effective thickness of soil from the soil DB, lype age, diameter and density from forest DB and land use. Then landslide possibility representing how possible to landslide was assessed by overlay of the susceptibility and rainfall frequency map, Finally, landslide risk representing how dangerous to people and facility was assessed by overlay of the possibil. ity and the population and facility density maps The assessment results can be used to urban and land use plan for landslide hazard prevention.

• The Journal of Engineering Geology
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• v.15 no.4 s.42
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• pp.435-445
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• 2005

Landslides induced by heavy rainfall from typhoon 'Rusa' in 2002 and typhoon 'Meami' in 2003 were investigated at Samcheok area, and the relationship between landslides and rainfall on that area was analyzed. The average annual rainfall at Samcheok area is generally $1,200mm\~1,300mm$. However, the average annual rainfall at samcheok for 2003 and ton was increased more than 2,000mm because of typhoon 'Rusa' and typhoon 'Meami'. The number of landslides and the landslides area are largely occurred in a area of the relatively high maximum hourly rainfall and 2days cumulative rainfall. Therefore, it confirmed that landslides are directly depended on the hourly rainfall and the cumulative rainfall. The landslides at Samcheok area induced by heavy rainfall due to typhoon are more influenced by the maximum hourly rainfall at the landslide occurrence day. In order to predict a rational landslide size, a new method included the maximum hourly rainfall and the landslide area in a traditional way was proposed. As the result of applying the new proposed method, the landslide size at Samcheok area is involved in the large scale landslide.

• Economic and Environmental Geology
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• v.44 no.4
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• pp.289-302
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• 2011

Since the frequency of the earthquake occurrence in Korean peninsular is continuously increasing, the possibility that massive landslides are triggered by earthquake is also growing in Korea. Previously, the landslide is known to be induced by large magnitude earthquake, whose magnitude is larger than 6.0. However, the landslide can be induced by only small magnitude earthquake, especially in the fully saturated soil. Therefore, the susceptibility of landslide caused by small magnitude earthquake in fully saturated soil is analyzed in this study. For that, the topographical and geological characteristics of the site were obtained and managed by GIS software. In the procedure of the study, slope angle, cohesion, friction angle, unit weight of soil were obtained and constructed as a spatial database layer. Combining these data sets in a dynamic model based on Newmark's displacement analysis, the landslide displacements were estimated in each grid cell. In order to check out the possibility of the earthquake induced landslides, the level of the groundwater table is varied from dry to 80% saturated soil. In addition, in order to analyze the effect of the magnitude of earthquake and distance to epicenter, four different earthquakes epicenters were considered in the study area.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.26 no.1
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• pp.27-39
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• 2008

Landslides cause enormous economic losses and casualties. Korea has mountainous regions and heavy slopes in most parts of the land and has consistently built new roads and large-scale housing complexes according to its industrial and urban growth. As a result, the damage from landslides becomes greater every year. In summer, landslides frequently occur due to local torrential rains and storms. It is critical to predict the potential areas of landslides in advance and to take preventive measures to minimize consequences and to protect property and human life. The previous study on landslides mostly focused on identifying the causes of landslides in the areas where they occurred, and on analyzing landslide vulnerability around the areas without considering rainfall conditions. Thus there were not enough evaluations of the direct risk of landslides to human life. In this study, potentially risky areas for landslides were identified using the GIS data in order to evaluate direct risk on farmlands, roads, and artificial structures that were closely connected to human life. A map of landslide risk was made taking into account rainfall conditions, and a land use map was also drawn with satellite images and digital maps. Both maps were used to identify potentially risky areas for landslides.

• The Journal of Engineering Geology
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• v.10 no.2
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• pp.18-35
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• 2000

The most dominant type of landslide in Korea is debris flows which mostly take place along mountain slopes during the rainy season, July to August. The landslides have been reported to begin activation when rainfall is more than 200mm within 2days. The debris flows are usually followed by translational slips which occur upper part of mountain slopes and they transit to debris flow as getting down to the valleys. Lithology, location, slope inclination, grain size distribution of soil, permeability, dry density and porosity have been proved as triggering factor causing translational slides. The triggering data taken from mapping are statistically analysed to get landslide potential quantitatively. Rock mass creeps mostly occur on well bedded sedimentary rocks in Kyeongsang Basin. Although the displacement of rock mass creep is relatively small about 1m, the creep can cause severe hazards due to relatively large volume of the involved rock mass. Examples are rock mass creep occurred in the mouth of Hwangryongsan Tunnel, in Chilgok and in Sachon in 1999. Although the direct factor of the creeps are due to slope cutting at the foot area, more attention is required A rotational slide occurring within thick soil formation or weathered rock is also closely related to bottom part of slope cutting. It is propagated circular or semi-circular type. Especially in korea, the rotational slide may be frequently occurred in Tertiary tuff area. Because they are mainly composed of volcanic ash and pyroclastic materials, well developed joints and high degree of swelling and absorption can easily cause the slide. The landslide among the Pohang-Guryongpo national road is belong to this type of slide.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.29 no.5
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• pp.535-541
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• 2011

A debris flow is caused by torrential rain in mountainous regions and carries mixture of fragmental matter from slope failure, deposit soils from a valley floor and a large amount of water. It seriously damages facilities, houses, and human lives in its path. We tried to apply debris flow behavior estimation model developed in foreign country to domestic case. The study area is Inje-county, Gangwon-do and aerial photos and GPS surveying were used to collect information of starting and end point of the landslide and debris flow. The analysis showed that L/H for forecasting the travel distances of debris flows has the mean of 4.93 and standard deviation of 0.98. This model tended to overestimate the scale and extent of debris flows. In Inje-county's case, a debris flow is caused by multiple simultaneous small-scale landslide. This is quite different from the foreign cases in which a large-scale landslide cause a large-scale debris flow. Thus, an empirical model suitable for domestic conditions needs to be developed.

• Journal of the Korean Association of Geographic Information Studies
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• v.12 no.2
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• pp.1-10
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• 2009

Recently the large scale of forest disaster such as landslide and forest fire gives a very bad impact on not only forest ecosystem but also farm business so that it has became the main issue of environmental problems. In this study, the landslide hazard area forecast method was developed by considering not only the topographic thematic maps based on GIS and satellite images but also amount of rainfall data, which are very important factors of landslide. Uljin-gun was selected as the study area and the GIS weight score and overlay analysis were applied to topographical map and meteorological observation map. Finally the landslide area distribution map was constructed by considering the evaluation criteria. Also, the accuracy could be acquired by comparing the landslide hazard area forecast map and real damaged area extracted from satellite image.