• Journal of The Geomorphological Association of Korea
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• v.18 no.4
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• pp.17-33
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• 2011

This study summarizes the research history of fluvial terraces in Korea and examines the geomorphic properties of fluvial terraces in Korea based on the previous works. The research history of fluvial terraces in Korea can be divided into the three periods. The theories of fluvial terraces were spread by the early geomorphologists during the period of Japanese colonial era to mid-1980s. The dissertations on the fluvial terraces were intensively published during the late 1980s to 1990s and their discussions were the center of geomorphology researches in Korea. Since 2000s, the discussions have become more mature and researches have been quantitatively increased as the various methodologies have been developed. The fluvial terraces in Korea are mostly developed in the western and eastern parts of the Taebaek Mountains, upper and middle reaches of Han and Nakdong River, and in the western slopes of Sobaek Mountains, middle reaches of Namhan River, upper and middle reaches of Geum and Seomjin River. Along these rivers in actively uplifted areas, fluvial terraces with much higher altitude from riverbed are observable and incision rates are relatively high. In the sense of the formation ages, they have developed in not regular patterns by the climatic changes during the Quaternary, but in more complicated aspects by the environmental conditions such as climate, hydrology, geology and geomorphology in the specific drainage basins.

• Journal of The Geomorphological Association of Korea
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• v.25 no.1
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• pp.67-80
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• 2018

This study used aerial and terrestrial images to build a three-dimensional model of cliffs located in Pado beach using SfM (Structure from Motion) techniques. Using both images, the study purposed to reduce the shadow areas that were found when using only aerial images. Accuracy of the two campaigns was assessed by root mean square error, and monitored by M3C2 (Multiscale Model to Model Cloud Comparison) method. The result of the M3C2 in closed areas such as sea cave and notch did not express the landforms partly. However, eroded debris on sea cliffs were detected as eroded area by M3C2, as well as in captured pictures by multi-camera. The result of this study showed the applicability of multi-camera and SfM in monitoring changes of sea cliffs.

• Journal of The Geomorphological Association of Korea
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• v.19 no.3
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• pp.51-69
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• 2012

Physical strength of the rock is the most important factor of resistance to erosion and has been measured through various way. Bedrock microforms, like potholes and grooves, are the forms sculpted by the erosional processes of flow and the location and morphology are strongly affected by the differential erosion. It also assumed that the physical strength of the rock controls the erosion rate and mode of erosion. The schmidt hammer has been used to measure the rock strength in the field for the geomorphological research. To find the relationship between the rock strength and microforms, Schmidt hammer's R(rebound) were measured in the Baeksuktan, middle reach of Gilancheon, Cheongsong, Gyungsangbuk do. The overall values of rebound of the local sandstone showed over 65 in most cases, so it can be regarded as 'very strong'. It is found that the rebound values of the rock surface decreased towards current water level. It also, however, found that there was no systematic differences in rebound values among the topographically high and lows in the bedrock surface. There was no statistically significant difference in rebound values of the area with well developed microforms and others. The values of R from the exposed faces and inside of the microforms are similar. In the case of conglomerate, the part with the gravel showed higher values that the parts with sands. The rebound values are decreased near of(<1cm) the geological discontinuities(including joint and faults), so this line of weakness could be the point of initiation of active erosion to form microforms. However there is large variations in rebound values within this part. It also should be mentioned that topological relation between the strike of the geologic discontinuities and flow direction looks control the mode of erosional processes.

• Journal of The Geomorphological Association of Korea
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• v.19 no.4
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• pp.27-37
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• 2012

This study investigated granite landforms formed by Hantan-gang fluvial erosion and deposition, or by weathering in the area neighboring the Seungil-gyo bridge in Cheorwon-gun Gangwon-do Korea, in which the contact zone of Myeongseongsan granite and Cheorwon lava plateau creates a unique landform. Major granite landforms are deeply weathered hill, sheet erosional landform, paleo-landform surface and paleosoil, micro-fluvial landforms such as pothole and groove, granite rampart, sand bar and boulder bar, former riverbed. And river cliffs on a weakly weathered dome act as a barrier to lateral shifting of the river.

• Journal of The Geomorphological Association of Korea
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• v.19 no.1
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• pp.109-121
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• 2012

Human responses, such as construction of levees, are a spatial representation of the place vulnerability which is induced by a geomorphic hazard like flooding. Human responses include all forms of human activities to reduce the place vulnerability and they seem to be related with reducing vulnerability rather than reducing geomorphic hazards. Diverse human responses to the perceived environment bring about changes in the place vulnerability. People respond spatially to their vulnerability of the place in diverse ways from their experience and perceived risk. Human responses have quantitative possibilities in predicting and modeling the place vulnerability. Building the model of a dynamic place vulnerability to the diverse geomorphic hazards requires basic maps of geomorphic processes and human responses in the region.

• Journal of The Geomorphological Association of Korea
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• v.25 no.4
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• pp.49-62
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• 2018

This study tries to reveal uplift rates inferred from relative and absolute ages on coastal terrace in the West and South Coasts of South Korea. Uplift rate from relative ages on Pleistocene coastal terrace in the West Coast rangesfrom approximately 0.059 to 0.282 m/ky, while a range of approximately 0.020~0.385 m/ky is calculated from the South Coast, suggesting that the South Coast shows higher rate than the West Coast. Based on absolute ages on coastal terrace during MIS 5 in the South Coast, on the other hand, the uplift rates 1 and 4 have ranges of approximately 0.042~0.062 m/ky and 0.051~0.087 m/ky, respectively, indicating that uplift rate in the South Coast is one-third to one-fourth to that in the East Coast. No research on absolute ages in West Coast terrace and lack of relative and absolute ages in the West and South Coasts are considered as the limit in this study.

• Journal of The Geomorphological Association of Korea
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• v.23 no.1
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• pp.103-115
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• 2016

At present, an acoustic Doppler current profiler (ADCP) is one of the most suitable tools for measurement of three dimensional flow characteristics in the river. The data resulting from this approach can be used for flow visualization and velocity mapping together with post-processing software tools. Among them, 'adcptools' is the latest one and provides more realistic velocity distribution in the cross-section since it uses velocity along the beam direction. In this study, a flow analysis was made using the 'adcptools' for the Amazon River and the Han River dataset. Discharge was recalculated and accuracy of discharge and velocity was evaluated. Streamwise velocity distribution and secondary flow pattern in cross-sections were visualized. Geo-referenced velocity distribution was also mapped. A summary with future prospect of 'adcptools' for studies on fluvial geomorphology is briefly given.

• Journal of The Geomorphological Association of Korea
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• v.24 no.3
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• pp.13-25
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• 2017

This study is quantitative reconstruction of palaeo sea level records around Sinduk-ri, Gochang-Gun. 7 cores were collected from GC14 to GC18 in order to examine the entire sedimentary facies and reconstruct the sea level records. The cores were analysed by AMS, sedimentary facies, diatom and WA-pls. As a result of the diatom analysis, diatom zone were classified as No diatom zone, B1 zone, M zone and B2 zone. The result of WA-pls was that the sea level was about 1.5m lower than the present level around 6,000 BP and about 1m lower during last 5,000 BP. Thereafter, sea level rose to the present during the Mc sub-diatom zone period. Moreover, during the Md sub-diatom zone period, sea level was about 0.5m higher than the present.

• Journal of The Geomorphological Association of Korea
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• v.23 no.2
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• pp.95-108
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• 2016

Several flights of marine terraces were developed along the Eastern coast of Korea (Gangneung-Donghae). Various dating techniques have been applied to determine the age of these terraces, with a view to better understand the regional uplift history. In this study, we compare the major element compositions of the terrace deposits and modern beach sediments to estimate the relative formation age of these terraces. We observed a discernible difference in major element geochemistry between modern beach sediments and various elevated terrace deposit (i.e. palaeobeach sediments). In general, weathering properties of marine terrace sediments are expected to be affected by the formation ages of terraces, and here, we confirm that the chemical composition are indicative of the relative age of the terraces in this region.

• Journal of The Geomorphological Association of Korea
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• v.24 no.3
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• pp.47-59
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• 2017

This study aims to analyze geomorphologically Jaein Falls in Hantangang Lava Plateau for the landform structure, landform classification, falls dissection and recession. The height and recession length of the Falls are approximately 18m and 340m. after dissection valley arrive at area of the Jijangbong Volcanic Rock Complex of Mesozoic era, the fall will disappear. The structure of the dissection valley shows totally well vertical columnar joint near falls and plunge pool, colluvial talus deposits toward lower reach by the freezing-thawing and wet-dry activities, and alluvial cone and delta in estuary to Hantangang River. The Falls' age date and recession rate in the valley maybe relate to the age of the lava plateau. The estimated recession rate of the fall should be 8.75m/ka to 2.3m/ka, depending on the age 500ka to 40ka in lava plateau.