• Journal of the Korean association of regional geographers
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• v.11 no.1
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• pp.19-28
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• 2005

Although Dokdo, small and dependent islands of Ulleung County, can be considered critical in terms of both geo-politics and physical geography, it is clear that Korean geographers have been too silent tn study Dokdo. In the author's view, such tendency is partly due to difficulties in access to Dokdo. In this sense this study would be meaningful for inquiring into the regional geomorphology of Dokdo regardless of only three-day field work. The major findings of the study are as follows. Firstly, the geology of Dokdo is composed of 8 rock units. Secondly, in a slope analysis of Dokdo volcano using GIS tool, steep slopes over $26^{\circ}$ account for 79.1% of whole slopes and even free faces, defined as slopes over $40^{\circ}$, account for 65.4%. Thirdly, the main landforms of Dokdo constitute volcanic landform, coastal landform and the others, such as talus, dyke, tafoni and erosional hollow. Fourthly, it turns out that advanced landform classification map of Dokdo can be designed by taking an approach tn regional geomorphology. Finally, based on a detailed review of the latest geological literature, I argue that part of landforms of East Dokdo(dongdo) is closer tn an erosional hollow than a small crater.

• Journal of the Korean Association of Geographic Information Studies
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• v.3 no.1
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• pp.44-56
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• 2000

Through the ISODATA method of unsupervised classification, the micro-landform of Gomso-Bay tidal flat was classified into mud, mixed, and sand flats by using Landsat TM image. Each tidal flat shows on apparent differences in its topographical characteristics and grain size compositions. Mud flat is occupied the innermost part of the tidal flat. Sand flat is distributed adjacent to the entrance of the bay, while the mixed one is located in the central part of the bay. Mud flat deposits have fine grain size, more than 4 in average mean phi, bad sorting, more than 1 phi in standard devation, and positive skewness. Mixed and sand flat deposits have coarse grain size, less than 4 average mean phi, good sorting, less than 1 phi in standard daviation, and negative skewness. Topographically, the mud flat consists of flat surfaces and dissected channels. The average depth of dissected channels is about 2 meters. Meanwhile, sand flat has a very flat landform with well-developed ripple marks of less than 10 centimeters in average relief. And the mixed one shows the intermediate topographical characteristics of those of mud and sand flats.

• Journal of The Geomorphological Association of Korea
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• v.24 no.1
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• pp.77-91
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• 2017

Many debris landforms in the mountains of Korea have formed in the periglacial environment during the last glacial stage when the generation of sediments was active. Because these landforms are generally located on steep slopes and mostly covered by vegetation, however, it is difficult to observe and access them through field investigation. A scientific method is required to reduce the survey range before performing field investigation and to save time and cost. For this purpose, the use of remote sensing and GIS technologies is essential. This study has extracted the potential area of debris landform formation using a fuzzy set model as a mathematical data integration method. The first step was to obtain information about the location of debris landforms and their related factors. This information was verified through field observation and then used to build a database. In the second step, we conducted the fuzzy set modeling to generate a map, which classified the study area based on the possibility of debris formation. We then applied a cross-validation technique in order to evaluate the map. For a quantitative analysis, the calculated potential rate of debris formation was evaluated by plotting SRC(Success Rate Curve) and calculating AUC(Area Under the Curve). The prediction accuracy of the model was found to be 83.1%. We posit that the model is accurate and reliable enough to contribute to efficient field investigation and debris landform management.

• Journal of The Geomorphological Association of Korea
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• v.25 no.1
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• pp.31-45
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• 2018

This study investigated the characteristics of sedimentary environment changes across a tidal flat in Gagyeongju of Anmyeondo Island. We performed a spatio-temporal analysis on the grain sizes composition of sediments and micro-landform changes during the winter from 2013 to 2016. The results showed that erosion was a dominant processthroughout the study flat, reducing the surface elevation even by 1 m around the upper sand flat. As a consequence, headlands have formed in the entire region of Gagyeongju village. In addition, erosion quickly progressed along the low-lying subtidal zone and tide way and, in contrast, sedimentation progressed in the mid-elevation tidal flat. We posit that a jetty, which had been constructed as a pier facility on the eastern part of the study area, interfered with the flow of tidal current, thereby enhancing these erosional processes. This is because such interference can block the supply of fine-textured sediments from the nearby Cheonsu Bay and therefore reduce surface elevation. According to the surface sediment analysis, the sediments were categorized into 7 sedimentary facies, and generally displayed a high ratio of silt and clay. The result of time-series analysis (2012-2013) showed that the sediments on the tidal flat became fine-grained, and that sorting became worse. However, the sediments on the subtidal zone, embayment and along inside of the jetty tended to be coarse-grained. In conclusion, the tidal flat microlandform change in the study area was caused by a disruption in the seawater circulation due to the jittery construction within the tidal flat, which had a direct effect on erosional and sedimentary environment processes.

• Proceedings of the KSRS Conference
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• 1998.09a
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• pp.110-115
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• 1998

Through the ISODATA method, the micro-landform of Julpo-Bay tidal flat was classified into mudflat, mixedflat, and sandflat using Landsat TM image. Each showed an apparent differences in its topographical characteristics and grain size composition. For example, mudflats are formed with flat faces and tidal channel of dissected gully. Its characteristics of grain size analysis that the grains have less than mean grain size 4 phi. Its sorting is bad (higher than 1 S.D.), and it showed strongly positive skewness. But sandflat is topographically flat without tidal channel. It has developed with ripple marks. According to the grain size analysis of deposits, the soil is coarse size with 90% of sand and its sorting is well(lower than 1 S.D.) Also, it showed strongly negative skewness. Mixed flat is in between mudflat and sandflat in its characteristics.

• Journal of The Geomorphological Association of Korea
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• v.21 no.4
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• pp.133-147
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• 2014

Reducing the range of target landform, is required to save the time and cost before real field survey in the case of inaccessible landform such as talus. In this study, Weight of Evidence modeling, which is a Target-driven spatial analysis statistics methods, has been applied to reduce the field survey range of target landform. In order to apply the Weight of Evidence analysis, a likelihood ratio was calculated on the basis of the result of correlation analysis between geomorphic factors and GIS information after selection of geomorphic factors regarding talus. A best combination, which has the biggest possibility for Talus Potential Index, was found by using SRC and AUC methods after calculating the number of cases for each thematic maps. This combination which includes aspect, geology, slope, land-cover, soil depth and soil drainage factors, showed quite high accuracy by 74.47% indicating the ratio of real existent talus to potential talus distribution.

• Journal of The Geomorphological Association of Korea
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• v.19 no.1
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• pp.1-15
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• 2012

The purpose of this study is to review research trends and issues of coastal geomorphology in general of Korea, which is divided into two periods; the former and later periods of 1990s when The Korean Geomorphological Society was established. In this study, coastal geomorphology in general refers to the landforms except tidal flats and coastal terraces. The descriptive statistics of research papers published in 5 major geography journals since 1990s were computed and these papers were classified according to their main subjects. The methodology for coastal landform study was analyzed by sub-fields of landform change and sediment analysis. The study of coastal geomorphology in Korea started from around 1970s and has progressed significantly in terms of the scope and the number of papers published since 1990s. There is few paper published in 1990s on coastal geomorphology in general, but so many research has achieved and came to be the major part of coastal geomorphology study since 2000s. Further methodology is necessary for morphodynamics study in the future.

• Journal of The Geomorphological Association of Korea
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• v.19 no.4
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• pp.139-155
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• 2012

Most of previous landform classification methods using DEM compares the values between the center of the cell and the surrounding cells, which in turn, greatly depends on analysis scale. To overcome the problem of scale-dependency, a new classification scheme is developed, which is called "Geomorphons". Unlike the traditional approaches using DEM, Geomorphons is the way which compares the level with other cells against the criteria cell. As a pilot study, we classify the landforms of Pyeongchang-Gun in Korea. Then, we compare the result with the other methods such as Topographic Position Index. Through the systematic analysis, we obtain the following findings. First, Geomorphons can reduce the time for the classification of landforms because of using unsupervised classification. Second, Geomorphons is little dependent on change in the scale, which can provide a pilot tool for reconnaissance study for covering large area.

• Journal of the Korean association of regional geographers
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• v.16 no.1
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• pp.1-15
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• 2010

A feng-shui map(山圖) represents the most ideal natural landform on a map of feng-shui space model, highlighting propitious spots and grave sites in terms of feng-shui. This study made an analysis into feng-shui maps featured in the Chinese feng-shui manual Jiriinjasuji published in the Ming dynasty of China and did research on the following points regarding the traits of landform expressions: viewpoints of feng-shui maps, perspective points, center-oriented maps, double map scales, mountain theories, detailed expressions of propitious spots, etc. The major characteristics of landform expressions in the Chinese feng-shui manual Jiriinjasuji are as follows: the viewpoint technique was aerial one; the maps were center-oriented, that is to say, the center of grave sites or propitious spot was depicted in detail; and often the important terrains around grave sites were exaggerated or delete compared with real landforms. In addition, other vital landforms not observed from grave sites were depicted with viewpoints moved and were represented in greater details' The part of mountain theories had the following points as their main subject matter: geographical locations, overall orientations of mountain ranges, topographical traits, grave seat directions, surrounding terrains and extent of fortune-bringing. The directions of the maps were relative and there was no definite concept of scales. But, there are many cases where the maps made use of the double scale technique when expressing the terrains that have propitious space, logistical cities or directional importance. Furthermore, they often utilized multiple scale in expressing near views, mid-range views and distant views.

• Proceedings of the KSRS Conference
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• 2004.10a
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• pp.148-151
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• 2004

In this study the micro landform of tide flat in west Seohan bay. North Korea was classified and the change of this environment was detected by using Landsat TM. FTM+, KOMPAST. For this. ISODATA method of the unsupervised methods was used to classify the micro landform while tasseled cap method was used to detect the change of environment in west Seohan bay, North Korea by passing years. This study shows the possibility that the topography analysis and change especially in unapproachable area could be detected and monitored by using satellite images.