• Journal of The Geomorphological Association of Korea
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• v.18 no.3
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• pp.21-36
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• 2011

Rock Weathering is a basic of geomorphological evolution as a preparation of materials. Of those, frost shattering has traditionally been considered as the operative process causing rock breakdown in cold regions as well as temperate zone. Each Granite(fresh rock, semi-weathered), Gneiss, Limestone, Dolomite was prepared slab specimens in ten, repeated freeze-thaw cycles of 180 under the -25℃~+30℃, and the changes was observed in physical properties and weathering aspect. Rock shattering was more active in waterlogging conditions rather than atmospheric and soil conditions. Limestone and Dolomite that high porosity are most severely crushed. Gneiss, regardless surface of the crack, joint, fissure and has a lowest rock strength(SHV), was even though no physical changes and their weathering product do not generate, has a very high resistance to weathering.

• Journal of the Korean Geographical Society
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• v.48 no.2
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• pp.204-217
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• 2013

This study shows the geomorphological processes of Yuga alluvial fan at Dalseong-gun, Daegu in Korea, based on characteristics of geomorphological surfaces, analysis of geomorphological deposits and OSL age dating. Alluvial fans of this area are classified into three surfaces(YG-F1, YG-F2, YG-F3) and were formed by the depositional processes resulting from the changes in hydraulic geometry of flowing water which was a stream flowing out of mountains debouched on to a plain, not by a sudden decrease in surface gradient of river bed. YG-F3 surface, about 110,000 yr B.P.(MIS 5.4), was formed as Yongri river deposited a lot of debris. This result was due to the process that the deposition took place actively with the upward of base level as the last interglacial period began. Later, the denudation of the river valley and geomorphological surface constantly occurred and the local and seasonal changes were found in precipitation and stream discharge with the beginning of the interstadial of the last glacial stages(MIS 3), leading to YG-F2 formed by debris flow, earth flow, mud flow and stream flow. Then, short-term climate changes and temporal climate events repeatedly caused aggradation and denudation over time and going through these processes, YG-F1 is believed to have been made by earth flow or mudflow during the last glacial maximum(MIS 2).

• Journal of the Korean Geographical Society
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• v.46 no.6
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• pp.693-706
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• 2011

The Geomorphological properties and ages of river-mouth bar at Song-cheon River in the East Coast of Korea, Yeongdeok-gun, Gyeongbuk Province are estimated, and the long-term and short-term changing processes and causes are analyzed. Sand grains of the bar near the coastline show the finer trends from south to north and these can be attributed to the northward movement of waves and long-shore currents. The absolute ages of bar and nearby coastal sand dune are less than approximately 100 years ago, indicating that the bar has experienced the active geomorphological changes. While the inlet located at south part of the bar between 1971 and 1995, the inlet has located at north or middle part since 1995. These may caused by the changes of movement directions of waves and long-shore currents due to the apparent northward movements of winds and currents. In short-term, the higher elevation, larger area, simpler landform relief and more variable location of inlet and morphology of bar can be observed between September and March due to the dominance of sedimentary processes by wave and wind processes.

• Journal of The Geomorphological Association of Korea
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• v.17 no.1
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• pp.85-93
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• 2010

After the notorious Taean Oil spill in Dec. 2007, a series of sand fences made of fishing net were installed in front of foredune in Shindu dune area. This paper aims to understand the temporal and spatial characteristics of morphological changes of the beach and foredune. About 1m high sand accumulated around sand fences for the last 2 years. While a lot of sand deposited during the winter season (from autumn to spring), small amount of sand eroded and deposited during summer season (from spring to autumn) without big morphological changes. These results mean that sand fences help nature deposit sand near beach and foredune area.

• Journal of The Geomorphological Association of Korea
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• v.27 no.1
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• pp.21-31
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• 2020

Planting pine trees on the coastal dunes has been carried out along the East coast as well as West coast of South Korea. Although the artificial forestation has been regarded as a good policy that help to protect the coastal area from natural disasters, but its real effect to the landscapes is still unknown. In this study, we have installed a monitoring site with an automated weather station to study requirements for dune formation and its environmental changes in Osan beach, Yangyang-Gun, Gangwon Province. We analyzed the meteorological data collected from 2010 to 2019 and vegetational changes in the study area. As a result, the wind speed is decreased by around 30% and the pine-covered area is increased by around 300m² after planting Japanese Black Pine in 2015. At present, it seems that the eolian transport of sand particle is minimal, because the dominant winds are the westerly winds which is not landward but seaward, and because the surface roughness length is about 0.5m which is similar to that in the deciduous forest.

• Journal of The Geomorphological Association of Korea
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• v.28 no.2
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• pp.45-57
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• 2021

In this study, the changes in morphology of Dokdo's gravel beach and its responses due to a storm event were analyzed using the aerial photos and 3D LiDAR data obtained during an ecosystem survey of the Dokdo in 2020. Dongdo Island's gravel beach, shown by aerial photo analysis, increased in area due to sedimentation after the construction of a dock, but there was no more significant changes in area after having grown to Sutdolbawi inside the dock. The changes in volume of the gravel beach were indicated based on 3D data acquired in May and November 2020. A strong typhoon that passed in September, 2002, caused erosion on the backshore and sedimentation on the foreshore and formed the berm by about 1.5 to 2 m high. The analysis showed that the sedimentation was 94.76 m³ in volume and 329 m² in area and the erosion was 250.75 m³ in volume and 603m² in area, which suggested that the overall change of the gravel beach was erosion. The changes in the morphology of the gravel beach on Seodo Island occurred with the seasons along with the changes in area. In addition, berms of different altitudes appeared on the southern and northern sides of the spit, which was also estimated to have formed by the seasonal current direction and wave energy.

• Journal of The Geomorphological Association of Korea
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• v.18 no.1
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• pp.101-112
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• 2011

Coastal terrace was developed at 7.2m height near Shinchon village in Geoje Island. It is located on the east side of southern coast in Korean Peninsula, where sea-level changes caused by ebb and flow of the tide, embayment are relatively low. Due to the breccia layer by mass-movement, dark grayish clayey formation, marine origin's rounded gravel are deposited sequentially in a cross-section of coastal terrace, so it provides a good example which understand Holocene sea level changes to determine the effect on the various sedimentary environments. For the purpose of identifying the morphogenetic process, Grain size, Roundness, XRD, AMS dating analysis was attempted. As a result, after last glacial age, Holocene sea level rise to +5.6m(4,740±100yrs BP). At that time, various geomorphological features are considered to be formed.

• Journal of the Korean association of regional geographers
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• v.14 no.2
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• pp.173-188
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• 2008

In order to make comparative analysis of geomorphological changes caused by urban development, I surveyed the distribution of geomorphological resources of 'Daegu Innovation Town' development plan area. The results are as follow: (1) At the front of small valleys of back-mountains are formed small alluvial fans, and at the side of small valleys are distributed hills connected with back-mountains. (2) As small valley erode laterally hills, vertical bluffs and planner bedrock riverbed are formed, and in some riverbed are appeared mud cracks and ripple marks. (3) The depth of valley in alluvial fan of 'Sinseo District' is 7m. In Sinseocheon valley dissecting alluvial fan, fluvial terraces 2m high above riverbed are distributed. Those terraces were formed while alluvial fan was dissected after last glacial period.

• Korean Journal of Remote Sensing
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• v.5 no.1
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• pp.1-12
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• 1989

The objective of this study is to develop the application techniques, such as geometrical correction, image overlapping etc., of LANDSAT Thematic Mapper image data especially useful to the geomorphological study of tidal flats. The developed processing techniques were applied to the Kum river estuary. The results of this study are as follows. 1) According to the analysis of the distribution and topographical profiles of the tidal flats, the geomorphological characteristics of the study area seem to be different depending on their location. 2) Even though the geomorphological changes were not always observable on the satellite images, several areas of undoubtful short-term deposition could be detected on the analytical map-image which compares two different situations of tidal flats. 3) Even though a further ditailed study is necessary, the distribution and dispersal patterns of suspended materials and sea surface temperature distribution patterns due to tidal and other meteorological conditions were analyzed by LANDSAT TM channel 3 and 6.

• Journal of The Geomorphological Association of Korea
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• v.28 no.1
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• pp.51-66
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• 2021

This study shows that coastal sand dunes are negatively affected by coastal forests. In South Korea, planting pine trees on the dunes has been carried out to stabilize the dune landscapes and protect residential areas from coastal disasters since the 20th century. However, this strategy could reduce the resilience of dunes. In this study, we selected three monitoring sites with automated weather stations to compare the geomorphological and environmental characteristics between tree-covered and grass-covered dunes at Sohwang-ri, Boryeong-si, Chungnam Province for three years. In addition, we monitored the rates of erosion and deposition using eight pins along the dune crests. We found that the forest affected both wind velocity and direction, resulting in decreased blown sand supply to the dunes in front of the forest. The velocity of the strong winds faster than 5 m/s diminished to 10%-30% of the control sites, and the direction of northwesterly wind were skewed to the north by about 6°. Sand deposition occurred at about 15-20 m away from the pine forest and the amount was only 1/10 of the deposition within the grass-covered dunes. This study suggests that planting trees in coastal dunes is an undesirable strategy with negative impacts on the landscape management.