• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2005년도 지반공학 공동 학술발표회
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• pp.655-662
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• 2005

The objective of this thesis is to develop a prediction system of potential landslide sites to apply to the prevention of landslide disaster which occurred during the heavy rainfall in the rainy season. The system was developed by combining a modified slope stability analysis model and a hydrological model. The modified slope stability analysis model, which was improved from 1-D infinite slope stability analysis model, has been taken into consideration of the flexion of the hill slopes. To evaluate its applicability to the prediction of landslides, the data of actual landslides were plotted on the predicted areas on the GIS map. The matching rate of this model to the actual data was 92.4%. And the relations between wetness index and landform factors and potential landslide were analyzed.

• 환경영향평가
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• 제16권5호
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• pp.373-379
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• 2007

Natural hazards such as typhoon, flood, landslide affect both coastal and inland areas more often according to increasement of severe and unusual weather. To provide adequate coastal disaster mitigation strategies, coastal disaster prevention system using GIS is very useful. Application methods of digital map on this issue was discussed in this study. For developing of coastal disaster prevention system, the data structures related to disaster monitoring is needed to be revised for interdisciplinary framework. To improve the current coastal disaster mapping methods, GIS based new model for coastal disaster mapping was suggested. In this study, coastal GIS showed the attribute data and structures of coastal disaster mapping.

• 대한원격탐사학회지
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• 제36권1호
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• pp.67-81
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• 2020

The rapid climatic changes being caused by global warming are resulting in abnormal weather conditions worldwide, which in some regions have increased the frequency of landslides. This study was aimed to analyze and compare the landslide susceptibility using the Frequency Ratio (FR), Statistical Index, Weight of Evidence, Certainty Factor, and Index of Entropy (IoE) at Woomyeon Mountain in South Korea. Through the construction of a landslide inventory map, 164 landslide locations in total were found, of which 50 (30%) were reserved to validate the model after 114 (70%) had been chosen at random for model training. The sixteen landslide conditioning factors related to topography, hydrology, pedology, and forestry factors were considered. The results were evaluated and compared using relative operating characteristic curve and the statistical indexes. From the analysis, it was shown that the FR and IoE models were better than the other models. The FR model, with a prediction rate of 0.805, performed slightly better than the IoE model with a prediction rate of 0.798. These models had the same sensitivity values of 0.940. The IoE model gave a specific value of 0.329 and an accuracy value of 0.710, which outperforms the FR model which gave 0.276 and 0.680, respectively, to predict the spatial landslide in the study area. The generated landslide susceptibility maps can be useful for disaster and land use planning.

• Spatial Information Research
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• 제20권3호
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• pp.57-66
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• 2012

강원도의 경우 대부분 산지로 이루어져 있어 산사태로 인한 피해가 매우 크다. 이러한 산사태를 예방하기 위해서는 산사태 발생에 영향을 미치는 기초적인 관련 인자를 분석하는 것이 중요하다. 본 연구에서는 강원도 인제군 인제읍 덕산리 지역을 대상으로 재해 직후 촬영된 항공사진을 이용하여 육안판독에 의한 디지타이징 방법으로 산사태 발생 및 미발생 지점을 추출하였으며, GIS를 이용한 지형도, 임상도, 토양도의 중첩분석을 통하여 산사태 관련 인자에 대하여 지형학적, 임상학적, 토양학적 특성을 수량화 2종법을 이용하여 분석하였다. 분석결과 경사도는 $20^{\circ}{\sim}35^{\circ}$ 사이에서 산사태가 많이 발생하였으며, 임상 인자의 경우 침엽수가 산사태 발생 빈도와 더 큰 연관성을 보였다. 토양 인자의 경우 유효 토심이 얕을수록, 토양모재가 산성암일수록 산사태 발생빈도가 높게 나타났다.

• Geomechanics and Engineering
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• 제28권3호
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• pp.283-298
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• 2022

Landslides triggered by the combination of heavy precipitation and anthropological disturbance in hilly areas cause severe damage to human lives, properties, and infrastructure constructions. A comprehensive investigation of the influencing factors and failure mechanisms of landslides are significant for disaster mitigation and prevention. This paper utilized the combination of detailed geological investigation, physical experimental testing as well as numerical modelling to determine the failure mechanism, and proposed a countermeasures of the Lantian landslide occurred on 2, July 2017. The results reveal that the Lantian landslide is a catastrophic reactivated slide which occurred in an active tectonic region in Southwest China. Because of the unique geological settings, the fully to highly weathered basalts in the study area with well-developed fractures favored the rainwater infiltration, which is the beneficial to slide reactivation. Engineering excavation and heavy precipitation are the main triggering factors to activate the slide motion. Two failure stages have been identified in the landslide. The first phase involves a shallow mass collapse originated at the upper slopes, which extends from the road to platform at rear part, which is triggered by excavation in the landslide region. Subjected to the following prolonged rainfall from 19 June to 2 July, 2017, the pore water pressure of the slope continually increased, and the groundwater table successively rise, resulting in a significant decrease of soil strength which leads to successive large-scale deep slide. Thereinto, the shallow collapse played a significant role in the formation of the deep slide. Based on the formation mechanisms of the landslide, detailed engineering mitigation measures, involving slope cutting, anchor cable frame, shotcrete and anchorage, retaining wall and intercepting ditch were suggested to reduce the future failure risk of the landslide.

• 한국산림과학회지
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• 제108권3호
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• pp.311-321
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• 2019

이 연구는 땅밀림위험등급을 구축하기 위하여 수행되었다. 땅밀림지의 평균산지경사는 $23.8^{\circ}$($11.8^{\circ}{\sim}37.0^{\circ}$), 땅밀림지 내에서 미세지형지의 평균사면경사는 $23.5^{\circ}$ ($10.7^{\circ}{\sim}41.5^{\circ}$)로 미소한 차이가 있는 것으로 분석되었다. 땅밀림지 및 땅밀림 재발생지에서 땅밀림지 내 등고선 간격과 땅밀림지 내 미세지형지의 등고선 간격은 5% 수준에서 유의한 결과를 나타내었다. 산사태위험등급에 포함되지 않는 땅밀림지는 전체 땅밀림지 중 1등급이 14개소(약 38.0%), 2등급이 6개소(약 16.0%), 3등급과 4등급이 각각 5개소(약 14.0%), 5등급이 16개소(약 43.0%), 산사태위험지등급 외 지역이 9개소(약 24.0%)이었다. 땅밀림지 중 산사태위험 1~5등급으로 지정되지 않은 면적 비율이 50.0% 이상인 지역은 8개소(약 22.0%), 20.0%~50.0% 이상인 지역은 18개소(약 49.0%), 20.0% 이상인 지역은 26개소(약 70.0%)이었다.

• 한국지반환경공학회 논문집
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• 제18권6호
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• pp.21-30
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• 2017

본 연구에서는 도심지 토사재해 예비중점관리 대상지역 중 충주시 안림동, 대전광역시 부사동, 안동시 신안동 3개 연구지역을 선정하여 지반특성을 분석하였다. 연구지역별 특성(수관밀도, 뿌리점착력, 강우특성, 토질특성)을 이용하여 지반특성 간의 상관관계를 고찰하고, 토사재해 예측 모델링을 통해 위험지역을 예측하였다. 토사재해 위험지 예측 모델의 비교 분석을 위하여 산지토사재해 예측프로그램(LSMAP), Stability Index MAPping(SINMAP), 산림청의 산사태위험지도(LHMAP)를 활용하였으며, 토사재해 예측에 적합한 프로그램을 검토하였다. 토사재해 위험도 예측결과 일반적으로 사용되고 있는 SINMAP의 경우 과다한 범위를 위험지역으로 예측하고, 산림청 산사태위험지도(LHMAP)의 경우는 예측지역이 가장 적게 산정되었으며, LSMAP은 SINMAP 및 LHMAP의 중간 정도 범위의 지역을 위험지역으로 예측하였다. 이러한 예측 결과의 차이는 LSMAP이 비교된 두 모델에 비해 분석 매개변수가 비교적 다양하고, 공학적이기 때문인 것으로 판단되며 보다 정밀한 예측이 가능하다는 것을 알 수 있었다.

• 한국지반환경공학회 논문집
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• 제17권12호
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• pp.5-16
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• 2016

This study aims to assess the influence of rainfall patterns on shallow landslides initiation. Doing so, five typical rainfall patterns with the same cumulative amount and intensity components comprising Advanced (A1 and A2), Centralized (C), and Delayed (D1 and D2) were designed based on a historical rainstorm event in Jinbu. Mt area. Those patterns were incorporated as the hydrological conditions into the Transient Rainfall Infiltration and Grid-based Regional Slope-stability Model (TRIGRS) to assess their influences on groundwater pressure and changes in the stability of the slope. The results revealed that not only the cumulative rainfall thresholds necessary to initiate landslides, but also the rate at which the factor of safety decreases and the time required to reach the critical state, are governed by rainfall patterns. The sooner the peak rainfall intensity, the smaller the cumulative rainfall threshold, and the shorter the time until landslide occurrence. Left-skewed patterns were found to have a greater effect on landslide initiation. Specifically, among five rainfalls, pattern (A1) produced the most critical state. The severity of response was followed by patterns A2, C, D1, and D2. Our conclusion is that rainfall patterns have a significant effect on the cumulative rainfall threshold, the build-up of groundwater pressure, and the occurrence of shallow landslides.

• 한국안전학회지
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• 제32권5호
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• pp.103-114
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• 2017

The landslide disaster damage has been increased by mountain development, leading to construction of educational facilities, medical facilities, petty industrial facilities, and large housing complexes. Therefore, effective regulation is required as an effort in urban planning solutions. For suggesting specific mitigation strategies on urban landslide, this study aims to define evaluation criteria for urban planning management of debris-flow disaster. AHP (Analytic Hierarchy Process), one of the multiple criterion decision making methods, was utilized in this study. This study makes use of 16 sub-criteria under the framework of hazard, exposure, and vulnerability, and well-planned expert survey measures their weights. The weights are also applied to evaluate each grid in urban space (min $10{\times}10m$) and classify it with red, orange, yellow, or green grade so that areas at higher risk are clearly identified. This study concludes that the suggested method is useful to support a strategies for urban planning management of debris-flow disaster, particularly in a GIS base.

• 한국지반환경공학회 논문집
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• 제17권4호
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• pp.17-31
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• 2016

Many researchers have evaluated the influence of vegetation cover on slope stability. However, due to the extensive variety of site conditions and vegetation types, different studies have often provided inconsistent results, especially when evaluating in different regions. Therefore, additional studies need to be conducted to identify the positive impacts of vegetation cover for slope stabilization. This study used the Transient Rainfall Infiltration and Grid-based Regional Slope-stability Model (TRIGRS) to predict the occurrence of landslides in a watershed in Jinbu-Myeon, Pyeongchang-gun, Korea. The influence of vegetation cover was assessed by spatially and temporally comparing the predicted landslides corresponding to multiple trials of cohesion values (which include the role of root cohesion) and real observed landslide scars to back-calculate the contribution of vegetation cover to slope stabilization. The lower bound of cohesion was defined based on the fact that there are no unstable cells in the raster stability map at initial conditions, and the modified success rate was used to evaluate the model performance. In the next step, the most reliable value representing the contribution of vegetation cover in the study area was applied for landslide assessment. The analyzed results showed that the role of vegetation cover could be replaced by increasing the soil cohesion by 3.8 kPa. Without considering the influence of vegetation cover, a large area of the studied watershed is unconditionally unstable in the initial condition. However, when tree root cohesion is taken into account, the model produces more realistic results with about 76.7% of observed unstable cells and 78.6% of observed stable cells being well predicted.