• Korean Journal of Ecology and Environment
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• v.46 no.1
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• pp.53-59
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• 2013

The purpose of this study was to analyze the topographic effect of the LAI (Leaf Area Index), which has been widely used as an index that quantifies the structure of forest vegetation in Deogyusan National Park. With this aim, the study was conducted through a regression analysis which took as explanation the following variables: the elevation, slope, aspect, and soil moisture conditions. The LAI was taken as the response variable. Overall, the correlation between the Field-LAI and topographic factors was less than 0.5, which was relatively low. Except for topographic altitude, there was no statistical significance regarding the correlation with other factors. Meanwhile, regarding the orientation of the correlation, the higher the attitude, the steeper slope, the lower the soil moist, the lower the LAI value. The topographic altitude was found as a statistically significant explanation variable. The TWI (Topographic Wetness Index), which was used in this study to explain the soil moisture conditions, was not significantly related to the LAI distribution. The results of this study are expected to be utilized as basic data in more accurate forecasting the LAI distribution using remote sensing data.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.35 no.5
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• pp.357-364
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• 2017

The purpose of the study is to develop and validate landslide susceptibility map of Bhotang village development committee, Nepal using FR (Frequency Ration) and SI (Statistical Index) methods. For the purpose, firstly, a landslide inventory map was constructed based on mainly high resolution satellite images available in Google Earth Pro, and rest fieldwork as verification. Secondly, ten conditioning factors of landslide occurrence, namely: altitude, slope, aspect, mean topographic wetness index, landcover, normalized difference vegetation index, dominant soil, distance to river, distance to lineaments and rainfall, were derived and used for the development of landslide susceptibility map in GIS (Geographic Information System) environment. The landslide inventory of total 116 landslides was divided randomly such that 70% were used for training and remaining 30% for validating result by receiver operating characteristics curve analysis. The area under the curve were found to be greater than 0.7 indicating an acceptable susceptibility maps obtained using FR and SI methods in GIS for hilly region of Nepal.

• Journal of the Korean Geosynthetics Society
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• v.18 no.4
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• pp.225-242
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• 2019

Rockfall failure at the access road to Seokguram were occurred due to the earthquake on September 12, 2016. A detailed investigation was carried out in order to find out the cause of the rockfall, to identify the risk of the entire sites, and to prepare proper countermeasure methods and mitigation. We checked for geological and topographical characteristics of overall slopes alongside the access road to Seokguram and made a face map. In addition, we analyzed topographical factors caused by the earthquake through calculating a degree of slope, degree of bearing, upslope contributing area, and wetness index with the use of shading relief map. As a result, we confirmed that the large rockfall occurred with a weak section. In this study, we also evaluated the overall slope stability of the entire access road to Seokguram in order to classify it into danger and caution zones depending on the risk of collapse.

• Korean Journal of Agricultural and Forest Meteorology
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• v.7 no.1
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• pp.78-90
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• 2005

The spatial and temporal distribution of soil moisture was characterized from soil moisture data through the intensive monitoring using Time Domain Reflectometry (TDR). The recession of soil moisture after a rainfall event was characterized and the empirical equation was used in the recession curve analysis. Recession analysis provides features of soil moisture variation such as recharge and stability depending upon locations of monitoring. The wetness index was useful for explaining spatial and temporal distributions of soil moisture and recession characteristics at hillslope scale.

• Journal of the Korean GEO-environmental Society
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• v.20 no.2
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• pp.5-18
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• 2019

In this study, it was conducted a broad-area landslide analysis for the entire area of Kyungsangbuk-do Province based on spatially-distributed wetness index and root reinforcement infinity slope stability theory. Specifically, digital map, soil map and forest map were used to extract topological and geological parameters, and to build spatially-distributed database at $10m{\times}10m$ resolution. Infinity flow direction method was used for rain catchment area to produce spatially-distributed wetness index. The safety level that indicates risk of a broad-area landslide was classified into four groups. The result showed that areas with a high estimated risk of a landslide coincided with areas that recently went through an actual landslide, including Bonghwa and Gimcheon, and unstable areas were clustered around mountainous areas. A comparison between the estimation result and the records of actual landslide showed that the analysis model is effective for estimating a risk of a broad-area landslide based on accumulation of reasonable parameters.

• Proceedings of the Korean Geotechical Society Conference
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• 2010.09a
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• pp.782-789
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• 2010

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 this study, performed a GIS-based landslide hazard analysis by SINMAP(Stability Index MAPping) model in Gyeonggi Icheon area coupling with geomorphological and geological data. SINMAP model has its theoretical basis in the infinite plane slope stability model with wetness obtained from a topographically based steady state model of hydrology. To Gyeonggi Icheon area landslides hazards evaluated, these SINMAP model were analysed results while simultaneously referring to the stability index map, where lines distinguish the zones categorized into the different stability classes and a table giving summary statistics.

• Journal of the Korean Society of Marine Environment & Safety
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• v.4 no.2
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• pp.43-52
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• 1998

Generally, the navigational safety of a ship under various loading conditions is evaluated by a loading manual. However, the loading manual handles only statical factors such as weight and buoyancy of ship without including any wave conditions. Practically ship's safety is much concerned with the occurrences on the rough sea as propeller racing, rolling, deck wetness, vertical acceleration, lateral acceleration, slamming and so on. The purpose of this paper is to present a synthetic and practical evaluation method of navigational safety using the integrated seakeeping performance index(ISPI) under loading conditions of ship in seaways. The method is calculated by means of the ISPI by measuring only vertical acceleration. Judgement of dangerousness is carried out for four lading conditions : homogeneous full loaded, half loaded, heavy ballast loaded, and normal ballast loaded conditions. In developing the practical evaluation system of navigational safety, it is useful to solve the difficulties in measuring factors by sensors. And by applying the evaluation diagrames, navigators are able to avoid dangerousness by keeping away of the danger encountering angle of wave direction which the diagram shows.

• Journal of The Geomorphological Association of Korea
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• v.20 no.1
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• pp.21-33
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• 2013

Weight of evidence model was applied for potential mapping of mountainous wetland to reduce the range of the field survey and to increase the efficiency of operations because the surveys of mountainous wetland need a lot of time and money owing to inaccessibility and extensiveness. The relationship between mountainous wetland location and related factors is expressed as a probability by Weight of evidence model. For this, the spatial database consist of slope map, curvature map, vegetation index map, wetness index map, soil drainage rating map was constructed in Yeongnam area, Korea, and weights of evidence based on the relationship between mountainous wetland location and each factor rating were calculated. As a result of correlation analysis between mountainous wetland location and each factors rating using likelihood ratio values, the probability of mountainous wetlands were increased at condition of lower slope, lower curvature, lower vegetation index value, lower wetness value, moderate soil drainage rating. Mountainous Wetland Potential Index(MWPI) was calculated by summation of the likelihood ratio and mountainous wetland potential map was constucted from GIS integration. The mountain wetland potential map was verified by comparison with the known mountainous wetland locations. The result showed the 75.48% in prediction accuracy.

• Proceedings of the KSRS Conference
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• 2008.10a
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• pp.378-381
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• 2008

The regulating and relaxing targets in the Land Use Regulation and Total Maximum Daily Loads are influenced by Land cover information. For the providing more accurate land information, this study attempted to generate an impervious surface map using KOMPSAT-2 image which a Korea manufactured high resolution satellite image. The classification progress of this study carried out by tasseled-cap spectral enhancement through each class extraction technique neither existing classification method. KOMPSAT-2 image of this study is enhanced by Soil Brightness Index(SBI), Green vegetation Index(GVI), None-Such wetness Index(NWI). Then ranges of extracted each index in enhanced image are determined. And then, Confidence Interval of classes was determined through the calculating Non-exceedance Probability. Spectral distributions of each class are changed according to changing of Control coefficient(${\alpha}$) at the calculated Non-exceedance Probability. Previously, Land cover classification map was generated based on established ranges of classes, and then, pervious and impervious surface was reclassified. Finally, impervious ratio of reclassified impervious surface map was calculated with blocks in the study area.

• Journal of Korean Society of Forest Science
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• v.102 no.1
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• pp.113-121
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• 2013

It has been known that edges of forest fire areas play significant roles in post-fire change of forest ecosystem and recovery process. The purpose of this study was to analyze the relationships between edge formation of burned forests and landscape characteristics with consideration on spatial autocorrelation. Samcheok fire site burned in 2000 was selected as the study area. Seven hundred fifty three of 500 $m^2$ grid cells were generated for measuring landscape characteristics. This study used the topographic variables including slop, elevation, topographic wetness index, solar radiation index and proportions of fuel and land use types. In delineating landscape characteristics correlation analysis with modified t-test were performed for exploring the relationships between edge formation and landscape characteristics. The results indicated that edge formation of burned forests was positively correlated with most variables including TWI, SRI, water, paddy, developed, farm, grass, bare soil, and negatively related with elevation, slope and all fuel types. Especially TWI (r=0.437) showed a strong positive correlation with edge formation. According to the results, edge of burned forests were likely formed when proportions of heterogeneous land use types were high with mild slope and low elevation.