• Proceedings of the Korea Water Resources Association Conference
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• 2006.05a
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• pp.2001-2005
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• 2006

우리나라는 매년 집중호우로 인한 산사태로 인해 인적, 물질적 피해를 일으킨다. 반복적인 산사태의 피해를 방지 하기위해서는 산사태 예측 시스템이 필요하다. 본 연구에서는 안성시를 대상으로 GIS와 RS 자료를 활용하여 산사태 위험지를 분석하고자 Logistic 회귀분석 방법과 AHP 기법을 이용하였다. Logistic 회귀분석과 AHP 기법에는 6개의 인자(경사, 경사향, 고도, 토양배수, 토심, 토지이용)를 사용하여, 7등급으로 산사태 위험도를 분류하였다. Logistic 회귀분석 방법과 AHP 기법을 이용한 산사태 위험지도를 표본 자료와 비교하면 산사태가 발생한 표본에서 산사태 위험성이 높은(1-2등급)지역이 Logistic 회귀분석에서는 46.1% AHP 기법은 48.7%로 분류되어 AHP 기법이 분류도가 높다고 분석 되었다. 하지만 Logistic 회귀분석과 AHP 기법은 서로 분석 과정의 차이를 가지고 있기 때문에 Logistic 회귀분석과 AHP기법을 적용한 결과에 동일 가중치를 부여한 후 7개 등급으로 재분류(reclass)하여 산사태 위험지역을 추출 할 수 있는 방법론을 제시하였다. 그 결과 산사태가 발생한 표본에서 1-2등급지역이 58.9%로 분석되어 분류정확도를 높일 수 있었다.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.51 no.2
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• pp.179-185
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• 2006

The Ministry of Agriculture and Forestry announced in 2001 that the overall amount of paddy land set aside for rice will be cut down by 12% by 2005, decreasing from 1.08 million to 953,000 hectares. When evaluating the value of paddy rice systems, the multi-function of paddy systems in the monsoon climate is vital importance. The main functions of paddy rice systems are to conserve biodiversity and maintain sustainability. Some crucial environmental benefits of the paddy rice systems include: flood prevention, recharge of water resources, water purification, soil erosion and landslide prevention, soil purification, landscape preservation and air purification. The paddy rice systems in Korea, which are more diverse than upland crop systems, are known to be composed of 14 orders, 36 families and 134 species. The sustain ability of paddy rice production systems can never be overestimated. Rice is part of the culture and even the heart of spiritual life in the area under the monsoon climate. Therefore paddy rice systems should be preserved with the highest priority being the enhancement of the systems' multi-function. As an outlook to future research, the need of joint and interdisciplinary research projects between economists and natural scientists at inland as well as international levels were emphasized in establishing the development of counter-measure logic through actual proofed analysis.

• Proceedings of the Korean Geotechical Society Conference
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• 2010.03a
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• pp.1-13
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• 2010

Numerous landslides had occurred in Kangwondo in July 2006 and several restoration works had been done. A-day-accumulative rainfalls from July 12 to July 13 and July 15 to July 16 were 176mm and 202mm respectively. Disaster sites at which slope failures were studied to main causes of slope failures by investigating characteristics of rainfall, geological formation, topography and ground surface exploration around the boundary of landslides. In this study, a series of slope restoration work process is presented for reference which about the landsliding area in Han-Gye-Ryeong to O-Saek in Kwangwon-do where one of the most severe damaged area in 2006. The slope restoration work process includes site investigation, analysis on affected factor, restoration or reinforcing method design, construction procedure and recent status of that area. Also several considering points are suggested while design and construction for the reference at the other restoration works.

• The Korean Journal of Ecology
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• v.25 no.1
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• pp.45-49
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• 2002

Pollen analyses and $^{14}$ C dating of the sediments of the Akindonuma moor, which is situated in a closed depression of an old landslide, were peformed in order to study the vegetation history of the montane zone of the Miyagi Prefecture, Northeast Japan. The main results are as follows: Two forest zones have been distinguished: 1) the A-I zone, or the Fagus-Quercus-Betula forest (R I stage, before about 11,700 yrs B.P.), and 2) the A-II zone, or the Fagus-Quercus forest (R II stage, after about 11,700 yrs B.P.). By comparing the geological section with the pollen diagram of the moor, it is assumed that the deposit environment of the Middle Part, which mostly consists of peat layers, is very stable. During the period, the Ulmus/Zelfkova pollen ratio was very low and small peak was not recognized. According to the preceding research, theme is a close relationship between the fluctuation of the Ulmus/Zelkova pollen ratio and the general trend of hillslope instability in the changing balance of temporature and precipitation Actually, Zelkova serrata tends to cover the footslope and the lower sideslope. Ulmus davidiana covers the footslope and the alluvial cone. Therefore, the fact that the Ulmus/Zeikova pollen ratio was very low and small peak was not recognized, is believed to reflect the stability of the earth's surface environment, which was estimated from the geological section.

• Journal of computational fluids engineering
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• v.22 no.1
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• pp.95-102
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• 2017

Debris flow is a composition of solid objects of various sizes, suspension and water, which occurs frequently as the results of landslide following heavy rainfall. This often causes extensive damage in the form of socio-economic losses and casualties as witnessed during the incident around Mt. Umyeon, Seoul in 2011. There have been numerous investigation to mitigate the impacts from debris flow; however, the estimation as preparedness measure has not been successful due to nonlinear and multiphase characteristics of phenomena both in material and process inherent in the debris flow. This study presents a numerical approach to simulate the debris flow using open source code of computational fluid dynamics, OpenFOAM with non-Newtonian viscosity model for three phase material modeling. In order to validate the proposed numerical method, the quantitative evaluations were made by comparisons with experimental results and qualitative analysis for the dispersion characteristics was carried for the case of debris flow in the actual incident from Mt. Umyeon.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.10 no.2
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• pp.57-62
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• 1992

As population is increased, land use types are changed mountainous areas from flatland in Korea. Because natural disaster as landslides occur of life, property, and environmental damage, prediction of landslides have become increasingly important. We focus on the issue for assessment of landslides, not slope stability analysis for a simple slope site. In this study, we could know the correlations of mean, standard deviation for brightness value of imagery by aerial photo scanning. The range of brightness values and standard deviation of landslide area is 35~65 and tend to increment of value, in the every years. When evaluating large regions with past occurrence of landslides, it is possible to search for correlation of site conditions such as degree of slope, soil characteristics, vegetative cover, and rainfall conditions in aerial photo interpretation data.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2005.10a
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• pp.387-392
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• 2005

The research was performed to predict the potential landslide with roughness index. It was known that fractal dimension and surface area index can be represented the topography, specially when the natural slopes were rough or rugged. A test site was selected and fractal dimension and surface area index were calculated from the irregular triangle network. Fractal dimension were ranged between $2.016{\sim}2.046$ and surface area index $1.56E+07{\sim}2.59E+07$. Surface area index increased as fractal dimension increased. Slope stability was calculated by infinite slope stability analysis model and was compared to slope stability by fractal and surface area index. In the result, unsafe zones where slope stability is under 1.1 were $5.11{\sim}6.25%$ for the test site. It can be said that fractal dimension and surface area index are a good index to evaluate the slope stability because when fractal dimension and surface area index are greater, then stability of the site is more unsafe.

• The Journal of the Korea Contents Association
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• v.7 no.3
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• pp.168-175
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• 2007

The flood caused landslide disaster each year because of climate change. And the change of topography from an earthquake makes topographical analysis impossible. This paper performed an investigation about a utilization methods and generation DEM(Digital Elevation Model) after digital aerial photographs quickly when the topographical change happens. Stereo imagery that was collected through digital aerial photographs made a generation of DEM possible. A standard deviation of generated DEM is 0.864m which is somewhat high but shows the real topography. As a result, it should be possible to generate DEM by using aerial photographs in case of the change of topography.

• Journal of the Korean Institute of Landscape Architecture
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• v.26 no.3
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• pp.34-44
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• 1998

The purpose of this study is to provide the basic data for land use in the future, which result from analyzing land use, obtained after studying on the natural environment by Geographic Information System and Remote Sensing. The results of this study are as follows : ·According to the classification of land-cover, agricultural land use is relatively prominent except for overall natural covering. According to the average value of Green Vegetation Index class, the average value of GVI is 3.0, and 45% of the regions have relatively good condition of floral state. ·With a view to natural environment, the survey shows that the altitude of 90% of the total areas is below 400m, and most of them are flattened or moderately-inclined area. Therefore, this region has a good condition to be used for development. · The area for the first class in preservation degree of natural scenery of Namcheon-Myun is 2.3% of the total areas. According to the results about unstable areas on all sides, unstable districs are distributed in so small-scale units that they will be safe from some damages drawn by developing activity. But we have to consider every aspects for the future development of them. In this study, the natural environment-variables are regarded firstly, and effective designation of the land with natural environment is researched too. However, to establish more practical developing plan, ecological and human variables should be regarded.

• Proceedings of the Korea Water Resources Association Conference
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• 2012.05a
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• pp.705-705
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• 2012

우리나라는 최근 여름철 태풍 및 집중호우로 인해 많은 토석류 및 산사태가 발생하고 있다. 작년 7월에도 집중호우로 인해 서울시 우면산 일대와 강원도 춘천에 많은 인적 물적 피해를 입었다. 해마다 반복되는 토석류나 산사태의 위험을 감소시키기 위해서는 보다 정확한 위험지역 예측모델을 필요로 한다. 본 연구는 토석류 및 산사태의 위험과 취약지역을 예측하기 위하여 GIS기반의 Weight of Evidence 기법을 적용하여 위험지역을 분석 하고자 한다. 2006년 태풍 에위니아에 의해 많은 토석류 피해를 입은 강원도 인제군 가리산일대를 대상으로 하였으며 토석류 및 산사태 위치 자료는 2005년, 2006년 토석류 발생 전후 항공사진의 중첩분석을 토대로 발생 지역을 추출하였다. 토석류 및 산사태발생에 영향을 미치는 지형, 지질, 토양, 수문, 임상 등의 인자들은 GIS를 이용하여 DB로 구축하였다. 베이시안 확률기법(Bayesian Method)에 기반 하여 구축된 DB와 결합하여 각각의 인자의 가중 값 W+, W-를 계산하여 상관관계를 분석하고 Weight of Evidence 기법을 적용하여 위험지역을 정량적으로 평가하고자 한다.