• 한국농공학회논문집
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• 제47권6호
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• pp.37-45
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• 2005

Almost every year, Korea has been suffered from serious damages of lives and properties, due to landslides that are triggered by heavy rains in monsoon season. In this paper, we systematized the physically based landslide prediction model which consisted of 3 parts, infinite slope stability analysis model, groundwater flow model and soil depth model. 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 $84.8\%$. And the relation between hydrological and land form factors and potential landslide were analyzed.

• Spatial Information Research
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• 제10권4호
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• pp.533-550
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• 2002

Soil organic matter (SOM) content and other physical soil properties were extracted from a digital soil database, the Soil Survey Geographic (SSURGO) database, to map the amount of SOM and determine its relationship with topographic positions in floodplain areas along a river basin in Douglas County, Kansas. In the floodplains, results showed that slope and SOM content had a significant negative relationship. Soils near river channels were deep and nearly level, and they had the greatest SOM content in the floodplain areas. For the whole county, SOM content was influenced primarily by soil depth and percent SOM by weight. Among different slope areas, soils on mid-range slopes (10-15%) and ridgetops had the highest SOM content because they had relatively high percent SOM content by weight and very deep soils, respectively. SOM content was also significantly variable among different land cover types. Forest/woodland had significantly higher SOM content than others, followed by cropland, grassland, and urban areas.

• 대한원격탐사학회지
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• 제26권6호
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• pp.665-673
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• 2010

The role of remote sensing in phenological studies is increasingly regarded as a key in understanding large area seasonal phenomena. This paper describes the application of Moderate Resolution Imaging Spectroradiometer (MODIS) time series data for vegetation classification using seasonal variation patterns. The vegetation seasonal variation phase of Seoul and provinces in Korea was inferred using 8 day composite MODIS NDVI (Normalized Difference Vegetation Index) dataset of 2006. The seasonal vegetation classification approach is performed with reclassification of 4 categories as urban, crop land, broad-leaf and needle-leaf forest area. The BISE (Best Index Slope Extraction) filtering algorithm was applied for a smoothing processing of MODIS NDVI time series data and fuzzy classification method was used for vegetation classification. The overall accuracy of classification was 77.5% and the kappa coefficient was 0.61%, thus suggesting overall high classification accuracy.

• 한국측량학회지
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• 제10권2호
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• pp.57-62
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• 1992

산지가 많은 우리나라에서는 인구가 증가함에 따라 토지의 이용이 평지에서 경사지로 이동되고 있으며, 산사태와 같은 자연재해는 인명의 손실, 재산상의 손실, 그리고 자연환경 파괴를 일으켜 그 연구의 중요성이 증가하고 있다. 산사태 예측에 있어서 단일사면에 대한 안정검토해석이 아닌 광범위한 지역의 위험지 예측은 중요한 과제라 할 수 있다. 본 연구에서는 산사태 지역의 항공사진 스캐닝으로 얻은 이미지밝기값의 평균 및 표준편차에 대한 상관관계를 알 수 있었다. 산사태 지역에서는 밝기값 범위가 35~65에 분포하였고, 표준편차가 경년변화에서 조금씩 증가하는 것으로 나타났다. 또한, 넓은 지역의 산사태 조사에서는 항공사진 자료에 의해 경사도, 토질특성, 피복상태의 상관관계를 구할 수 있다.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2008년도 추계 학술발표회
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• pp.893-903
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• 2008

A method for predicting surface failures which occur during heavy rainfall on mountain slopes is proposed by using the digital land form model that is obtained by reading altitude on a topographical map at 10m grid point space. A depth of a potential failure layer is assumed at each grid point. In the layer, an infiltrated water movement from cell to cell is modeled in the study (cell is a square of the grid). Infiltrated ground water levels which show the three dimensional effects of a topographical factor in an area can be hourly calculated at every cell by the model. The safety factor of every cell is also calculated every hour by the infinite slope stability analysis method with the obtained infiltrated ground water level. Failure potential delineation is defined here as the time when the safety factor becomes less than unity under the assumptions that effective rainfall is 20mm/h and continues 20 hours.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2015년도 학술발표회
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• pp.214-214
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• 2015

Rainfall induced landslides is one of the most devastating natural disasters acting on mountainous areas. In Korea, landslide damage areas increase significantly from 1990s to 2000s due to the increase of both rainfall intensity and rainy days in addition with haphazard land development. This study was carried out based on the application of TRIGRS unsaturated (Transient Rainfall Infiltration and Grid-based Regional Slope stability analysis), a Fortran coded, physically based, and numerical model that can predict landslides for areas where are prone to shallow precipitation. Using TRIGRS combining with the geographic information system (GIS) framework, the landslide incident happened on 27th, July 2011 in Mt. Umyeon in Seoul was modeled. The predicted results which were raster maps showed values of the factors of safety on every pixel at different time steps show a strong agreement with to the observed actual landslide scars in both time and locations. Although some limitations of the program are still needed to be further improved, some soil data as well as landslide information are lack; TRIGRS is proved to be a powerful tool for shallow landslide susceptibility zonation especially in great areas where the input geotechnical and hydraulic data for simulation is not fully available.

• 한국농공학회논문집
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• 제64권4호
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• pp.31-43
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• 2022

In this study, we estimated the monthly FDSI (Flash Drought Stress Index) for assessing flash drought on South Korea using AMSR2(Advanced Microwave Scanning Radiometer 2) satellite-based soil moisture footprints. We collected the AMSR2 soil moisture and climate-land surface data from April to November 2018 for analyzing the monthly FDSI values. We confirmed that the FDSI values were high at the regions with the high temperature/evapotranspiration while the precipitation is relatively low. Especially, the regions which satisfied an onset of flash drought (FDSI≧0.71) were increased from June. Then, the most of regions suffered by flash drought during the periods (July to August) with the high temperature and evapotranspiration. Additionally, the impacts of landuse and slope degree were evaluated on the monthly FDSI changes. The forest regions that have the steep slope degree showed the relatively higher FDSI values than the others. Thus, our results indicated that the the slope degree has the relatively higher impact on the onset and increasing of flash drought compared to the others.

• 한국환경복원기술학회지
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• 제26권2호
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• pp.47-59
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• 2023

This study investigated and analyzed the effects of vegetation on the roadside slopes at the expressway construction sites in order to evaluate the vegetation recovery regarding soil type and revegetation technique. We selected two study sites with an area of 1,000 m² located in the construction sites of the Korea Expressway Corporation, named Hwado-Yangpyeong Expressway Section 3 and Saemangeum-Jeonju Expressway Section 7. The revegetation was monitored in three plot groups (earth, soft rock, and hard rock slopes), and scored based on the guideline of the Ministry of Land, Transport and Maritime Affairs. The revegatation was generally lower in the Hwado-Yangpyeong site than that of the Saemangeum-Jeonju site. The field monitoring indicated that the revegetation varied with slope aspect and environmental characteristics between plots. the Saemangeum-Jeonju site showed a high overall evaluation score, but there was a slight difference in the score for each plot. This seems to be due to the differences in geographical conditions, construction methods, and site environment between two sites. This study can provide basic information to understand the short-term effects of revegetation techniques in the roadside slopes.

• Steel and Composite Structures
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• 제47권4호
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• pp.451-454
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• 2023

Landslides are one of the natural disasters that cause a lot of financial and human losses every year It will be all over the world. China, especially. The Mainland China can be divided into 12 zones, including 4 high susceptibility zones, 7 medium susceptibility zones and 1 low susceptibility zone, according to landslide proneness. Climate and physiography are always at risk of landslides. The purpose of this research is to prepare a landslide hazard map using the Hierarchical Analysis Process method. In the GIS environment, it is in a part of China watershed. In order to prepare a landslide hazard map, first with Field studies, a distribution map of landslides in the area and then a map of factors affecting landslides were prepared. In the next stage, the factors are prioritized using expert opinion and hierarchical analysis process and nine factors including height, slope, slope direction, geological units, land use, distance from Waterway, distance from the road, distance from the fault and rainfall map were selected as effective factors. Then Landslide risk zoning in the region was done using the hierarchical analysis process model. The results showed that the three factors of geological units, distance from the road and slope are the most important have had an effect on the occurrence of landslides in the region, while the two factors of fault and rainfall have the least effect The landslide occurred in the region.

• 자원환경지질
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• 제48권2호
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• pp.177-185
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• 2015

본 연구의 목적은 예비조사 방법으로서 점검표를 이용하여 토질사면에 대한 산사태 취약도를 평가하고, 산사태 재해위험지도를 만드는 것이다. 국립재난안전연구원이 제안한 표들이 사면 안정성 평가에 적용되었으며, 이 표들은 토질사면에 대한 안정성 점검표로 구성되어 있다. 흙의 공학적 특성을 포함한 자료들은 부산 중심부의 황령산 지역에 대한 현지조사와 기존 연구를 통하여 획득되었다. 주제도를 만드는데 관련된 모든 자료는 ArcGIS 10.0을 이용하여 변환되었다. 이 방법을 사용한 결과 연구지역의 토질사면은 매우 안정-안정 영역에 분포되었으며, 중간 정도의 안정성 영역은 산의 말단부를 따라 부분적으로 분포한다. 산사태 위험도 지도의 결과는 산사태에 의한 피해를 방지하고, 적절한 토지이용계획을 수립하는 데 이용될 수 있을 것이다.