• Journal of The Geomorphological Association of Korea
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• v.26 no.2
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• pp.15-27
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• 2019

This study tries to reveal transport mechanism and origin of components from fluvial terrace deposits in Danyang and Geum River basins, through grain size partitioning using the Weibull function. Grain size parameters suggest that the samples analyzed in this study can be grouped into the coarse, fine and medium samples. The coarse samples are partitioned into three or four components. More than 65% of the coarse samples consist of components by suspension and saltation by fluvial process, while components by attachment to coarse grains or aggregates and/or by individual grains deposited under non-flow condition are also found in the coarse samples. The fine samples consist of four components and components found in loess deposits in Korea occupy >70%, suggestive of the same transport mechanisms (westerlies and winter monsoon) and common source areas with loess deposits in Korea. However, components by aeolian process from local sources as well as by fluvial process are also found in the fine samples. The medium samples are partitioned into components with similar sizes to the coarse and fine samples, respectively.

• Journal of The Geomorphological Association of Korea
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• v.26 no.3
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• pp.19-30
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• 2019

This study summarizes domestic and foreign previous works on fluvial terrace with absolute ages to discuss formative process of climatic terrace in Korea. Different from traditional climatic terrace model, approximately three quarters from foreign works have argued that formation of climatic terrace can be attributed to medium- and short-term climatic change or other environmental factors, rather than long-term climatic change of glacial and interglacial cycles. Based on previous works on fluvial terrace in Korea, it can be suggested that fluvial terrace in Korea formed not due to long-term climatic change of 100,000-year cycles related to glacial and interglacial cycles, but due to medium- and short-term climatic change or climatic event of tens of thousands of years related to intensity change in summer monsoon, one of the important factors affecting precipitation in Korea.

• The Korean Journal of Quaternary Research
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• v.22 no.2
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• pp.43-44
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• 2008

In this brief present are about some advanced results from investigation geomorphology in basin of river Tui and distribution of relief their peculiarities, types morphogenetic, convert to ekzogen process of relief ( fluvial system, permafrost process, wind process, slope process etc) and dynamic process of sedimentation.

• 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.24 no.1
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• pp.39-50
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• 2017

This study was conducted to analyze the variation of hydro-geomorphological environment along Baekgok wetland, which experiencing periodical inundation, in that water-level fluctuation of reservoir caused by irrigation. Since the field data is unavailable, modeling techniques, involving models such as HSPF and TELEMAC-2D, have been applied to simulate hydrological cycle in watershed and hydrodynamics in channel scale. The result of simulation indicates that the water-level of reservoir determines both the water surface extension and water depth in the wetland. Furthermore, it also shows that water-level functions as a spatial limit factor for a fluvial environment and woody vegetation such as willow. The fact of which the scale of water-level fluctuation being larger than an average topographical relief along the wetland can explain the result. While the water-level kept high, the wetland is submerged and waterbody becomes lentic. In contrast, while the water-level is lowered, fluvial phenomena of which being dependent on flow rate and channel shape become active. Hence, the valid fluvial process is likely to take place only for 4 months annually just near the channel, and it advances to a conclusion expecting a deposition to be dominant among the wetland except for such area. It is anticipated that such understanding can contribute to establishing plans to preserve the geomorphological and ecological value of the Baekgok wetland.

• Journal of the Korean Geographical Society
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• v.39 no.1
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• pp.27-44
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• 2004

Upper reach of Soyang River at the northernmost area around Taebaek Mountains in South korea is profitable area to understand paleo-environment during the Quaternary such as tectonic process and climate change in the Korean Peninsula. This study explained paleo-environment affect to channel development by geomorphic distribution and characteristics of terrace surfaces, and analysis of deposits at 58 fluvial terraces in upper reach of Soyang River. Fluvial terraces were classified from T1 to T6. Most terraces are distributed on the point bar in meandering channel and one side along river valley. Terraces tend to decrease in number and superficial dissection rate to be higher and channel slope to be steeper if it takes long time from T1 to 6. The paleo-channel of Soyang River is supposed to be stronger meandering in period of T2 than T3. The weathering rind of gravel is generally thicker in older terrace, however, differs by contents of water and air in deposits. Based on the data of stratigraphy, grain size analysis, pollen analysis and rubification index in deposit, formation age of T5 terrace in Soyang River are estimated in MIS(Marine Oxygen Isotope Stage) 10, and T2 terrace are estimated in MIS 6.

• Journal of the Korean Geographical Society
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• v.40 no.6 s.111
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• pp.716-729
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• 2005

In the Yeongpyeong River, one of the branches of Hantan River, there 4 fluvial terraces are identified. During the Quaternary, lava flow from Hantan River had gone 4.5km into upstream Part of the Yeongpyeong River and damed its entrance, and resultantly its lower basin had become a lava-damed paleolake. This study deals with fluvial terrace surface classification, stratigraphic analysis, deposits analysis, and OSL age dating in from Gungpyeongri to Seongdongri in lower reach of Yeongpyeong River, in order to identify Seomorphological Process of the terrace landforms relating to duration of lava-damed paleolake. Terrace surface T4, named Baekeuiri Formation, has been located under Jeongok lava layer to indicate pre-lava river bed. Terrace surfaces T3 and T2 are supposed to be formed during paleolake time, based on $3{\~}4m$ thick sand deposits including pebble and cobble layers, and clay and silt layers intersected with sand ones in nearly horizontal bedding. Terrace T1 is estimated to be formed as post-lake fluvial terrace after dissection of lava dam, based on the more fresh phase of deposits and very low height from present riverbed. The results of the OSL age dating for the T3 deposit layers indicate approximately $33{\~}40ka$, and still lake phase at that time.

• International Journal of Advanced Culture Technology
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• v.3 no.2
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• pp.15-24
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• 2015

Currently, abundant wastes from the palm oil refining process have been generated which are hard to handle. Spent Bleaching Earth (SBE) is the solid waste from this process and leads the cost of elimination to the company. This study aims to utilize the SBE as the alternative material in the non-fired wall tiles. The main raw materials used in non-fired wall tiles consist of laterite soil, fluvial sand, and Portland cement. The experimental formulas have been conducted and divided into 3 groups by varying the percentage of the SBE in main raw materials. The specimens of material mixture have been produced by uniaxial pressing at 100 bars, dimensions in $50{\times}100{\times}8mm$. These specimens are sprayed with water and cured in the air for 7 days. After that, bending strength and water absorption test of these specimens has been performed. It can be concluded that the best formula with the percentage of laterite soil, fluvial sand, Portland cement, and SBE are 60.94%, 13.125%, 22.5%, and 3.435%, respectively. Its bending strength and %water absorption are 0.68 MPa and 5.64%. Material costs of specimen are approximately $0.00276 USD/100g. Furthermore, the comparison of curing period between 7 days and 30 days has been performed. The 30 days of curing period can improve the bending strength of the specimen, but there is no effect on water absorption.

• Journal of the Korean Institute of Landscape Architecture
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• v.37 no.6
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• pp.96-105
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• 2010

This study identified the dynamic process of sandbar and vegetation distribution of the sandbar on the Tan-cheon River. The study area is located in the lower reaches of the Tan-cheon River that has been managed as an Ecosystem Reserve Area since 2002. For the study, the geomorphological process was analyzed through mapping analysis using a satellite image followed by analysis of the vegetation distribution through an on-site survey. The major findings were as follows : First, In the fluvial geomorphic process, various kinds of sandbars were developed in 1990s, the morphologic characteristics changing continuously. Second, In the distribution of vegetation on the sandbar, the sandbar shore was covered with bare sand substrate or intermittent annual vegetation because of the periodic fluctuation of the water-level due to intensive disturbances. Third, In the relationship between the sandbar formation and vegetation, four types of sandbars were classified: channel-shore stable bar, channel-shore unstable bar, mid-channel stable bar and mid-channel unstable bar, according to the fluvial disturbance & vegetation process. The study verifies that the vegetation distribution is reciprocally related to the geomorphological process. Accordingly, it is meaningful in the selection of plant species and the planting area of the sand bar. However, it is limited to the planting guidelines on river restoration projects. More diverse on-site experimental studies should be conducted.

• Journal of The Geomorphological Association of Korea
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• v.25 no.4
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• pp.1-19
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• 2018

This study tries to identify distributional characteristics of stream incision rates at 23 points in the northern part of the Taebaek Mountains. Soyang-gang, Naerin-cheon, Odae-cheon, Dong-gang and upper reaches of Okdong-cheon Rivers closed to the Range show higher incision rates and the rates clearly decrease with distance from the Range. Therefore, the incision process in the northern part of the Range has been greatly influenced by uplift around the Range, and the Sobaek Mountain Range seem to play a role in the incision process. Limestone areas show lower incision rates due to degradation of terrace surface by dissolution. This study suggests that local hydrological, geological and geomorphological conditions can be regarded as an important factor in stream incision rates, although stream incision rates are greatly influenced by regional uplift.