• Journal of The Geomorphological Association of Korea
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• v.26 no.1
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• pp.107-119
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• 2019

In recent years, the drying of the water spider habitat has been progressing rapidly. This is the primary cause of extreme climatic events in 2014/2015 with overall reduction in annual precipitation, but impermeable clayey layer formed in the superficial formation also plays an important role. The clayey layer is a critical factor in the formation of wetlands on a well-drained lava plateau, but paradoxically, it restricts the connection with ground water, increasing the instability of the water balance and making it precipitation-dependent structure. In addition, construction of roads/drainways has also caused drying of wetlands by blocking or rapidly spilling surface water/sheet flow. Therefore, to keep the wetlands sustainable, it should increase the flow into the wetlands by removing the road/drainways and floodgates installed to reduce the outflow.

• Journal of The Geomorphological Association of Korea
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• v.28 no.3
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• pp.1-11
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• 2021

The drainage area of the Miho stream is composed of granitic basins, gneissic and sedimentary mountains. 80 percent of the Miho stream flows through the Jincheon basin and the Cheongju inner-plain within the Daebo granite belt. Because the deep weathering of granitic hills provides a large amount of sands to the streams, there are wide floodplains with thick alluvium developed in the basin and plain. The thickness of the alluvium is 5~10m and the width of the floodplains is 2~2.5km. In the basin outlet area where a stream passes through the mountain canyon, wide floodplains and deep alluvium are developed in other riverside. The Miho stream is a sand-gravel channel flowing through the Cheongju inner-plain with wide floodplains and deep alluvium formed by deep weathering of granite.

• Journal of The Geomorphological Association of Korea
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• v.24 no.1
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• pp.13-24
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• 2017

This study analyzes altitude changes of riverbed at 6 bridges in the upper and lower reaches of Yeongju Dam in Naeseong River, from 2009 to 2016 just before and after the dam construction. For 5 years from November 2010 to December 2015 when the dam was under construction, approximately 0.091m of the riverbed altitude in average more than twice before the dam construction was lowered, because of the effects of riverbed excavation for riverside maintenance in the upper reaches and transport limitation of flow and sediment by the dam in the lower reaches. Between November 2009 and December 2016 when the dam was in pre-construction and post-construction stages, respectively, the most sites in this study in the upper and lower reaches showed lowering in the riverbed altitudes. On the other hand, the riverbed around Hoeryongpo closed to the river mouth seems to be influenced by channel changes in Nakdong River rather than by the dam construction.

• Journal of The Geomorphological Association of Korea
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• v.23 no.3
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• pp.1-11
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• 2016

This study estimated vegetation environment and agricultural activity during the late Holocene inferred from pollen analysis of peat on floodplain of Wangpo-cheon around Neungsan-ri, Buyeo-gun, South Korea. By result of pollen analysis of 28 horizons from Trench NS 1 and NS 4, vegetation environment during 2,300 to 1,700 yr BP was divided into Pollen Zone I (Quercus-Alnus), Pollen Zone II (Quercus-Alnus-Gramineae) and Pollen Zone III (Pinus-NAP-Gramineae). The pollen analysis suggests that agricultural activity in the Buyeo area was widely spread from the early time of the Pre-Iron Age to the late Samhan Age and buckwheat field seem to be built to substitute paddy field during the early time of the Pre-Iron Age.

• Journal of The Geomorphological Association of Korea
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• v.24 no.4
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• pp.117-129
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• 2017

This study is to develop a Geotourism program focused on Taean Haebyeongil course 5 (coastal walkway) and to introduce an explanation board to revitalize an effective Geotourism program of the Taeanhaean National Park. Generally Geotourism program is developed by analyzing topography, geology and cultural resources of the Taean Haebyeongil course 5. An explanation board, which is revitalizing an effective Geotourism program can be used when explaining each trekking courses and providing information about observable geological features to the visitors. This study suggested a new method of explaining geological features and cultural resources to visitors of the Taeanhaean National Park. Additionally, developing a new program of Taean Haebyeongil, is believed to provide a diversity of locational contents to visitors. Hopefully this new program will boost the tourism business of Taean Haebyeongil.

• Journal of The Geomorphological Association of Korea
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• v.23 no.3
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• pp.27-39
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• 2016

This study statistically investigates relationships between physical properties of rocks and topography by measuring and analyzing section, topographical and measured parameters of 58 bedrock outcrops at areas covered by gneiss, schist, granite, andesite, sandstone and limestone in the Korean Peninsula. Multiple linear regression analysis suggests that the joint spacing, joint continuity, weathering grade and maximum joint width of rocks among the measured parameters are related to the topographical parameters with statistical significances. Therefore, this study suggests that rock properties such as joint spacing, joint continuity, weathering grade and maximum joint width seem to greatly influence topography, although various factors can affect topographical parameters.

• Journal of The Geomorphological Association of Korea
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• v.23 no.1
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• pp.1-16
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• 2016

This study estimates relationships between physical and chemical weathering indices of various rock types and topographical relief. Physical weathering properties such as rock strength and joint and chemical weathering indices such as the $SiO_2/Al2O_3$, CIA and WPI were analyzed from 18 rock outcrops in mountain and valley areas consisting of 9 rock types. The results indicate that the elevation and relief of topography increase physical strength of rock increases. It can be suggested that the total r(rock-mass strength rating) and R(rock rebound strength by Schmidt Hammer) are most useful indices as a quantitative weathering property factor to explain formative causes of topographical relief. The results also suggest that rock types such as sandstone, granite, gneiss and schist are most suitable to explain meaningful difference in topographical relief with the physical and chemical weathering indices.

• Journal of The Geomorphological Association of Korea
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• v.23 no.1
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• pp.35-45
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• 2016

Aiming to elucidate the formation processes of Myeonsan wetland around the ridge from Myeonsan peak to Seokgae pass, this paper analyzes the geomorphic, physical and chemical characteristics of the wetland. The results are as follow: Firstly, resistant bedrock and big boulders distributed on the riverbed of the small channel from the wetland to Seokgaecheon have played a role as a temporary base level. At the upstream part above this point, a wide and shallow depression was formed and developed into a wetland. There was a gorge covered with boulders at downstream part. Secondly, owing to the obstacles at the outlet of wetland, deposits on bed tend to be downstream coarsening. Finally, deposits show weak acidity of pH 5.0~5.7. The source of wetland water is groundwater containing rich Ca and Na. Trees in the wetland help much more Ca accumulated. And deposit biotite and amphibole contained rich Mg have been weathered in the wetland.

• Journal of The Geomorphological Association of Korea
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• v.23 no.2
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• pp.1-13
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• 2016

This study analyzed pollen compositions in archaeological site on alluvial plain of Taehwa River, Taehwa-dong, Ulsan-si vegetational and environmental change during 6,200~3,000 yr BP. The results consist upward of Pollen Zone I (Inner Bay environment), Pollen Zone II (Quercus-Alnus stage) and Pollen Zone III (Alnus stage). The pollen grains of Fagopyrum and reddish gray silty horizon including artifacts of the Bronze Age suggest that there was cultivation on dry-field around the study site, although it is not sure that there was paddy-field cultivation.

• Journal of The Geomorphological Association of Korea
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• v.25 no.3
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• pp.105-120
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• 2018

This study estimates possibility and limitation on production of DEM using aerial photo by comparison of DEMs using aerial photo and digital map. Mountain and urban areas show higher elevation in DEM using aerial photo than in DEM using digital map, due to height of vegetation cover and buildings, respectively. However, artificial affects due to bridge, embankment and road construction are responsible for areas with higher elevation in DEM using digital map than in DEM using aerial photo. This difference in elevation between DEMs seems to be caused by rapid change in real elevation that is not reflected in digital map. There is little difference in elevation between DEMs in plain and area with little or no vegetation cover. This study suggests that problems associated with vegetation cover and error by GCP should be fixed, although DEM using aerial photo can quantitatively and 3-dimensionally reconstruct topography with a high resolution.