• Proceedings of the KSRS Conference
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• 2003.11a
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• pp.7-9
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• 2003

The objective of this study is to evaluate flood risk area by integrating GIS and RADARSAT data. The study area, Northeast Thailand, is subject to flood during the rainy season. The main data used in this evaluation included RADARSAT data, landform and topographic map. The evaluation was conducted by overlay operation of flood area in 2001, land form and buffer region beyond the flood areas with the selection criteria defined. Most of the flood risk areas were found in the low lying land form within the buffer region. The cloud penetrating capabilities of SAR is only a source of information for effectively assessment of flood risk area in Northeast Thailand.

• Journal of the Speleological Society of Korea
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• no.88
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• pp.51-62
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• 2008

동굴내부의 지형변형은 동굴내의 외인적인 요인과 내인적인 요인에 의하여 발달된다. 외인적인 요인으로서 기후변동에 의한 기온의 변화와 침출수의 증감 및 외부 이입물질 등을 들 수 있으며, 내인적인 요인으로서는 암석의 공극율, 지질환경, 단층 및 습곡면의 형상, 절리 및 균열면의 유무, 동굴지천의 구배 및 유속, 층리간의 이종의 암석게재 여부 등을 들 수 있다. 동굴 시스템은 수문 물리화학적 요소에 의해 형성되며 외부 기준면 통제에 의해서 암석학, 구조학, 기후학, 생물학, 토양학 등과 밀접한 상태에서 의존적인 발달 과정을 가진다. 동혈 내부의 침식은 유수의 입력 경우 유출과정에서 형성되며, 또한 유수의 비 입력 경우유출 및 액체용액의 분출에 의해서 형성된다. 다수의 동굴학자들은 동굴은 계절마다 침수되거나 빨리 흐르는 홍수에 의한 폭우에 의해 epiphreatic 상태에서 간헐적으로 포화되는 과정을 거치며 선택적으로 발달한다고 주장하고 있다. 혼합지대 동굴의 가장 좋은 예는 현재의 카르스트 지역에서 나타나는 것이 아니라 과거 제4기의 200만년전 동안보다 해수면이 더 안정적이었던 때에 이루어진 고 카르스트(Paleo Karst)에서 발견되고 있다.

• Journal of the Korean Geographical Society
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• v.49 no.5
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• pp.656-674
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• 2014

The objective of this study was to examine the distinctiveness and generality of landforms of the Korean peninsula, and further discover geomorphological principle that can be applied to land and environmental management in Korea. The research targeted East Asia and Korea, with terrain analysis conducted at a continental scale, national scale, and regional scale sequentially. East Asia displays complicated characteristics and evolutionary history of geotectonics, but exhibits distinct northeast-southwest geomorphological structure and connectivity at the continental level. While the Korean peninsula follows this pattern on a continental scale, it also features NNW-SSE direction (Nangrim and Taebaek Mountains) geomorphological connectivity that intersects at a right angle. From a national perspective, the Korean peninsula hosts the most diverse geomorphological features within East Asia. It does not have a high average altitude, but has relatively high slope angle and intricate topographical distribution in comparison to neighboring areas. While the mountains and plains of the Korean peninsula display a smooth connection, geomorphologically similar areas such as Shikhote-Alin, Huanan in China, and Japan have clear characteristics that divide the mountains and plains. Despite the distinctiveness and diversity that appear in East Asian topography on the regional scale, the connectivity that links the top of mountain (hill) to stream is identical among all areas as a general rule. It is collectively considering the connectivity and the geomorphological and ecological processes that arise within this connectivity that will serve as the focal point for sustainable landscape management.

• Journal of the Korean Geographical Society
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• v.44 no.2
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• pp.122-145
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• 2009

Terrain parameters calculated from digital elevation models (DEM) have become increasingly important in current spatially distributed models of earth surface processes. This paper investigated how the ability of upslope area for predicting the spatial distribution of soil properties varies depending on the selection of spatial resolutions of DEM and algorithms. Four soil attributes from eight soil-terrain data sets collected from different environments were used. Five different methods of calculating upslope area were first compared for their dependency on different grid sizes of DEM. Multiple flow algorithms produced the highest correlation coefficients for most soil attributes and the lowest variations amongst different DEM resolutions and soil attributes. The high correlation coefficient remained unchanged at resolutions from 15 m to 50 m. Considering decreasing topographical details with increasing grid size, we suggest that the size of 15-30 m may be most suitable for soil-landscape analysis purposes in our study areas.

• Journal of the Korean Geographical Society
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• v.47 no.5
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• pp.654-676
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• 2012

This study aims to develop an ecoregion classification using a multi-hierarchy of environmental factors for spatial patterns in the capacities and potentials of ecological systems in mountain regions. To achieve the objectives, we describe the spatial distribution of environmental factors and identify the multi-hierarchy of these factors using spatial statistics. Lastly, we assess ecosystem-units using both a forest type map (yung & kung) and a forest soil map in order to present a ecoregion classification. This study was performed at a $1,168km^2$ area in Gangwon-do, Korea. Sedimentary rocks, particularly limestone (36.6%) exist in high proportions in the research area. While higher mountains are present in the north and central Korean peninsula, plain areas show large proportions along Odae and Pyeongchang river. In a multi-hierarchy, geology and elevation are identified as upper levels and landform classification (surface curvature, upslope area) is considered as a lower level. 'Geology+elevation+landform' shows equally higher ${\chi}^2$ values than that of other classifications and we map ecoregions based on this result. Uniqueness of environmental characteristics in the research area such as high proportions of sedimentary rocks and higher elevations influences our ecoregion classification. We are looking forward to considering this study as an effective approach to integrating various ecological themes for mountain ecosystem management.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.19 no.1
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• pp.121-133
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• 2016

It was required to evaluate ecological restorations in a comprehensive way in order to systematically manage conservation areas such as DMZ and national parks in South Korea. In this research we developed a new approach to evaluating ecological restorations with more various indexes than vegetation covering-related indexes. By analyzing damaged areas in the vicinity of DMZ, major damaged types were identified as six classes: landform modification, surface loss, soil pollution, soil physio-chemical modification, vegetation decline and vegetation damaged. From literature review, 39 indexes were selected and were grouped into four divisions: soil property, vegetation growth & structure, habitat property and landscape structure & functions. By conducting a survey with the selected indexes targeting relevant experts, data on relative importance among the divisions and indexes by damaged type were collected. As a result, it was found that the orders and values of weighted values of the divisions were different by damaged type: for example, soil property (0.402), vegetation growth & structure (0.209), habitat property (0.225), landscape structure & function (0.163) for "landform modification"; but soil property (0.171), vegetation growth & structure (0.401), habitat property (0.270), landscape structure & function (0.158) for "vegetation decline". Similarly, evaluation indexes showed different orders and values of relative importance, easiness in field measurement and representativeness for the division by damaged type, and the values were used for calculating importance factor for each index. In the evaluation table, score1 and score2 were made by the importance factors of indexes multiplied by distribution values which present grades and by the weighted values of divisions. In conclusion, while dealing with the damaged type was considered significant for evaluating and managing restorations, further tests on this table with a range of cases were needed to improve its quality.

• Journal of the Korean association of regional geographers
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• v.13 no.5
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• pp.563-575
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• 2007

This study aims to investigate a possibility of using topographic information by web mapping in open environments. Web mapping intends to focus on a map analysis and application of the function and geo-visualization. Functions of Web topographic info-map include a spatial analysis, enlargement and minimization, movement, landuse information, user-controling 3 dimension map, landform cross-section analysis, shortest path analysis. The web system adopts SVG(scalable vector graphics), MYSQL, PHP, XML for mapping. SVG has open source policy, so everyone can use it, as well, it is effective on flexible database linkage, cartographic representation. 3D map is intended to represent 3D map by user-controlled sunshine putting pixel opacity by elevation values after making DEM. Landform is designed to show a cross-section analysis and statistics by retrieving height information from database engine with clicking two points on the map. Shortest path analysis within regions uses Dijkstra's algorithm. Near future, resultantly, the area of WebGIS will have to meet more social demands for use-created geo-information and application, so more researches are needed to be web mapping more applicable for users.

• Journal of the Korean Association of Geographic Information Studies
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• v.10 no.1
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• pp.194-204
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• 2007

The purpose of this paper was to propose a Topographic Position Index(TPI) method for predicting forest wetlands, and also to test the suitability of the predicted forest wetlands by comparing with the existing wetlands in Ulaju-gun and Gyengsangnam-do. A prediction of the spatial distribution of forest wetlands was accomplished by TPI grids from Digital Elevation Model(DEM), and the classification results of slope position and landform categories in study area using the TPI values. According to the results of predicting forest wetlands distribution by TPI method, the predicted area in case of less than $5^{\circ}$ flat slope criteria occupied 0.1%($1.38km^2$) of the total area, and 3.5%($37.1km^2$) of total area in below $10^{\circ}$ slope criteria. According to the results of the suitability analysis by comparing the predicted area with the existing forest wetlands, the suitability value (0.066) of the predicted area with less than $10^{\circ}$ flat slope criteria was the highest, but the predicted area in case of less than $20^{\circ}$ had the lowest value(0.019).

• Journal of the Korean earth science society
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• v.27 no.5
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• pp.548-556
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• 2006

The purpose of this study is to clarify the relict landform development of fluvial terrace and the soil characteristics occurring on the fluvial deposits. The physico-chemical properties of soil that are developed on terrace deposits and X-ray diffraction analysis of clay were investigated specifically. The horizon of $A_1$ consists of silt loam with reddish-brown color (5YR4/3). Its soil structures is a weak, fine, subangular, and blocky, breaking to granular. The horizon of $B_{1t}\;and\;B_{2t}$ are silt clay with either a yellowish red (5YR5/6), bright red (2.5YR4/6) color. This soil structure is weak, subangular, and blocky, with thin discontinuous bright red (2.5YR4/6) clay cutans and soft manganese concretions. This red soil structure is made on heavy-textures. It is packed compactly with parent materials of high fluvial surface sediments, and usually has a $A_1-B_{1t}-B_{2t}-C$ profile, from top to bottom. In most cases, clay accumulation in the B-horizon and clay cutans on ped surfaces are observed, which means the argillic horizon has formed. The soils derived from fluvial surface deposits are associated with soils. The soils on the high fluvial surface are considered to be a kind of paleo-red soil which were developed by strong desilicification and rubefaction, and strong leaching of bases under warmer bio-climatic condition during the old Pleistocene period. According to these morphological and anlaytical characteristics,geomorphological features and bio-climatic conditions under which the soil have developed on the high terrace sediment indicate that the soil should be classified as paleo-red soils.

• Economic and Environmental Geology
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• v.24 no.4
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• pp.399-408
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• 1991

There are several tuff cones and tuff rings, now only apparent on the western shoreline in Cheju Island. The observation of their landform, bedform, particle size and sorting reveals that these deposits are mainly emplaced by base surges and/or slurries originating from Surtseyan eruption which is attributed to explosive hydrovolcanism influenced by interaction of magma with external water. These are subdivided into two groups based on the plateau basalt. It is recognized that the distal limb of early tuff cones and ring at Dangsanbong, Dansan, Sanbangsan and Hwasun (lower group) are overlain by plateau basalt, on which later tuff rigns at Suwolbong and Songaksan(upper group) further extend the distal limb from each vent. The tuff cones and tuff rings are closely associated with the evidences which shelly fragments are comprised within them, and reworked tuffs, raised beach deposits, Sinyangri formation and littoral cones are deposited around them. The evidences suggest that the Surtseyan eruption resulted from direct or indirect interaction of magma with sea water.