• Economic and Environmental Geology
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• v.37 no.5
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• pp.499-508
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• 2004

Changwon City first constructed riverbank filtration plants in Book-Myeon and Daesan-Myeon in Korea in the year 2001. This study evaluated hydrogeological characteristics and groundwater flow simulation between the Nakdong River and the fluvial aquifers adjacent to the river in Book-Myeon, Changwon City. The groundwater simulation calculated the influx rate from the Nakdong River and the fluvial aquifers to pumping wells through the riverbank filtration system. The groundwater flow model utilized drilling, grain size analysis, pumping test, groundwater level measurements, river water discharge and rainfall data. Hydraulic heads calculated by the steady-state model closely matched measured heads in pumping and observation wells. According to the transient flow model, using a total pumping amount of 14,000 $m^3$/day, the flux into the pumping wells from the Nakdong River accounts for 8,390 $m^3$/day (60%), 590 $m^3$/day (4%) is from the aquifer in the rectilinea. direction to the Nakdong River, and 5,020 $m^3$/day (36%) is from the aquifer in the parallel direction to the Nakdong River. The particle tracking analysis shows that a particle from the Nakdong River moves toward the pumping wells at a rate of about 1.85 m/day and a particle from the aquifer moves toward the pumping wells at a rate of about 0.75 m/day. This study contributes to surface water/groundwater management modeling, and helps in understanding, how seasonal change affects pumping rates, water quality, and natural recharge.

• Journal of the Korean association of regional geographers
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• v.3 no.1
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• pp.51-62
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• 1997

In various places of drainage basins of major rivers in South Korea are distributed intermontane basins. Basin floor covered with fluvial deposits carried from the surrounding mountane area becomes alluvial plain. Its productivity is comparatively higher than anywhere else. Thus basin is a local administrative, economic, and cultural core area. Intermontane basin consists of backward mountane area, gentle hills, and alluvial lowland. The purpose of this paper is to elucidate the morpogenetic processes and development age of Angae Basin located in the sedimentary rock region. Hills with the height of a.s.l. $80{\sim}100m$ distributed in Angae Basin are residual landforms, which are the remnants of dissection of the etchplain that results from the denudation of bedrock deeply weathered along tectolineaments under the warm and moist climate, and reflect lithological differentiation of bedrock. Those hills have been comparatively higher ridges since the initial stage of the original etchplain, and they have been immune from fluvial processes. The etchplain appeared as $80{\sim}100m$ hills. the high terrace distributed in upstream reach of Nakdong River drainage basin and the old meander-cut at Seoburi in Wicheon drainage basin, are formed at the same stage when riverbed of Wicheon Stream functioned as a local base level according as the fluvial system of Wichoen arrived at dynamic equilibrium.

• Journal of the Korean Geographical Society
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• v.43 no.6
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• pp.775-790
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• 2008

This study shows possibility of active fault, throughout analyzing distributional features of tectonic and fluvial geomorphology and mineral composition of fault fracture clay, at Jinbu fault-line system in Pyeongchang-gun, Gangwon Province. Fault-line valley was formed remarkably in the upper reaches of Odae River and upper reaches of Yeongok River according along Jinbu fault-line. Landforms show rectilineal distribution at right shore slopes of Odae River in Ganpyeong-ri, southern zone of Jinbu fault-line system, related to the tectonic processes, such as triangular facet, kernbut, kerncol and alluvial fan. Fault fracture clay zones were developed at 5 outcrops($jbf1{\sim}5$), located in kerncol. Particularly, jbf1 fault outcrop, developed at granite saprolite, has obvious fault plane and fault clay composed of illite and laumontite. The Jinbu Fault-line along jbf4-2-3-5 may be formed by regional compressive stress, and jbf1 fault may be suggested a tributary fault of the Jinbu fault-line formed before the late Pleistocene. The vertical displacement of the east and west blocks of the Jinbu Fault-line is estimated in $0.024{\sim}0.027m/ka$.

• Water Engineering Research
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• v.3 no.4
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• pp.259-267
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• 2002

South Africa has developed a policy and law that calls and provides for the equitable and sustainable use of water resources. Sustainable resource use is dependent on effective resource protection. Rivers are the most important freshwater resources in the country, and there is a focus on developing and applying methods to quantify what rivers need in terms of flow and water quality. These quantified and descriptive objectives are then related to specified levels of ecological health in a classification system. This paper provides an overview of an integrated and systematic methodology, where, fer each river, and each river reach, the natural condition and the present ecological condition are described, and a level/class of ecosystem health is selected. The class will define long term management goals. This procedure requires each ecosystem component to be quantified, starting with the abiotic template. A modified flow regime is modelled for each ecosystem health class, and the resultant fluvial geomorphology and hydraulic habitats are described. Then the water chemistry is described, and the water quality changes that are likely to occur as a consequence of altered flows are predicted. Finally, the responses to the stress imposed on the biota (fish, invertebrates and vegetation) by modified flow and water quality are predicted. All of the predicted responses are translated into descriptive and/or quantitative management objectives. The paper concludes with the recognition of active method development, and the enormous challenge of applying the methods, implementing the law, and achieving river protection and sustainable resource-use.

• Nuclear Engineering and Technology
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• v.44 no.8
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• pp.871-888
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• 2012

This paper aims at presenting the state of the art, the recent progress, and the perspective for the future, in the modelling of two-phase flow in the horizontal legs of a PWR. All phenomena relevant for safety analysis are listed first. The selection of the modelling approach for system codes is then discussed, including the number of fluids or fields, the space and time resolution, and the use of flow regime maps. The classical two-fluid six-equation one-pressure model as it is implemented in the CATHARE code is then presented and its properties are described. It is shown that the axial effects of gravity forces may be correctly taken into account even in the case of change of the cross section area or of the pipe orientation. It is also shown that it can predict both fluvial and torrential flow with a possible hydraulic jump. Since phase stratification plays a dominant role, the Kelvin-Helmholtz instability and the stability of bubbly flow regime are discussed. A transition criterion based on a stability analysis of shallow water waves may be used to predict the Kelvin-Helmholtz instability. Recent experimental data obtained in the METERO test facility are analysed to model the transition from a bubbly to stratified flow regime. Finally, perspectives for further improvement of the modelling are drawn including dynamic modelling of turbulence and interfacial area and multi-field models.

• Journal of Korea Water Resources Association
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• v.37 no.1
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• pp.1-11
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• 2004

The purpose of this study consists in introducing and examining the previous river classification systems applicable to the river improvement technique including geomorphological considerations, and developing a new system using the geomorphological criteria which represent the morphology of rivers. A newly developed system uses the channel reach as a classifying unit which is delineated by upstream and downstream tributaries. It adopts three basic geomorphological criteria for classification: 1) valley-floor width index(VI) reflecting the confinement of the channel in the valley, 2) sinuosity(P) which expresses the channel planform, and 3) bed material($d_{50}$). The system is composed of 24 stream types. Concerning every stream type, valley forms, principal bed forms and fluvial processes with disturbance elements are briefly presented. Finally, the applicability of this system to the Chungmi Stream and the Imjin River data in comparison with that of Rosgen system is examined.

• Journal of The Geomorphological Association of Korea
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• v.24 no.2
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• pp.15-25
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• 2017

Subi basin is located at the crestline of Taebaek mountains. This paper aims to elucidate the geomorphic development of Subi basin through the analysis of river terraces built in Wangpi-cheon and Banbyeon-cheon. Wangpi-cheon flows northeastward from Subi basin, and Banbyeon-cheon flows southward at the west of Subi basin. Absolute age of terrace is measured by means of OSL methodology, long profile of Wangpi-cheon is made up with 10m interval contour line, and the elevation above river bed of high terraces is measured at the end part of terrace. The results are as follow: Firstly, high river terraces of Subi basin, Wangpi-cheon and Banbyeon-cheon are formed about 40 kyr(MIS 3) being interstadial stage of last glacial period. Secondly, the elevation above river bed of high terraces of Wangpi-cheon and Banbyeon-cheon tends to increase toward upstream. It means that the uplift of Taebaek Mountains influences considerably the formation of their terraces. Thirdly, the elevation above river bed of high terraces at the reach from Seomchon to Suha-ri of Wangpi-cheon tends to decrease toward upstream. This section is captured from Banbyeon-cheon flowing in the opposite direction. River piracy has occurred from the time of formation of Suha-ri high terrace to the time of formation of Hantee wind gap. Finally, for fluvial system of Wangpi-cheon to establish dynamic equilibrium, topographic axis will move toward Banbyeon-cheon.

• Journal of the Korean earth science society
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• v.39 no.6
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• pp.545-554
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• 2018

The Cretaceous Eumsung (Eumseong) Basin is a pull-apart basin, formed along a series of the Gongju strike-slip faults trending NE-SW. The Nongdari-Meer forest of the Gugokri area in the southwestern part of the basin is comprised of thick purple mudstone, intercalating conglomerate, pebbly sandstone, and green mudstone beds. The succession mainly consists of seven sedimentary facies: stratified conglomerate (C2), conglomerate encased in siltstone (CE), stratified pebbly sandstone encased in siltstone (PSE2), purple sandy siltstone (Zp), green sandy siltstone (Zg), purple mudstone (Mp), and green mudstone (Mg). Sedimentary environment is mainly indicative of alluvial-plain setting in an alluvial-to-lacustrine sedimentary system, developed in the southwestern part of the basin. Geological survey was fulfilled in succession of the Gugokri sedimentary system using 1:5000 topographic map, which resulted in a geological route map. This study newly suggested that there be fluvial systems showing ENE and NNE trends in the study area, based on data of palaeocurrent direction and sedimentary characteristics in new outcrops of the forest. The study also revised the precedent sedimentation model of the Gugokri system.

• Journal of Environmental Impact Assessment
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• v.16 no.1
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• pp.59-68
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• 2007

Urban streams have been severely degraded with wastewater and concrete structure over a prolonged period. The Chonggyecheon Restoration Project recovered a stream in the downtown Seoul with landscaping, plantings and bridges after the cover concrete and elevated asphalt road were removed. The project has been criticized partly because it is not an ecological restoration but rather the development of an urban park with an unnaturally straight flowing stream, artificial building structures, and artificial water pumping from the Han River. Nevertheless, the public have praised the project and almost 100,000 visitors per day come to see the reeds, catfish, and ducks. The stream restoration project is attractive to central and regional government decision makers because it increases the public concern of landscape amenity. Several projects such as Sanjichon and Kaeumjungchon are on going and proposed. These projects have a common and different respect in scope and procedure. The Chonggyecheon project in the process of environmental impact assessment (EIA) and prior environmental review system (PERS) reviewed the environmental impacts before development. Kaeumjungchon in the PERS and Sanjichon without EIA and PERS are reviewed. EIA and PERS systems contribute to checking the ecological sustainability of the restoration projects. A stream restoration project is a very complex task, so an integrated approach from plan to project is needed for ecologically sound restoration. Ecological stream restoration requires 1) an assessment of the entire stream ecosystem 2) establishing an ecologically sound management system of the stream reflecting not only benefits for people but also flora and fauna; 3) developing the site-specific design criteria and construction techniques including habitat restoration, flood plains conservation, and fluvial management; 4) considering the stream watershed in land use plan, EIA, PERS, and strategic environmental assessment (SEA). Additionally the process needs to develop the methodologies to enhance stakeholder's participation during planning, construction, and monitoring.

• Geophysics and Geophysical Exploration
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• v.8 no.2
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• pp.119-128
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• 2005

The assessment of erosional and depositional patterns near bridge piers is essential to understand the fluvial scour process. Geophysical surveys are particularly effective in determining the riverbed variations in a river and may also be of value for obtaining the previous scour history below the riverbed profile. In this study, GPR (Ground Penetrating Radar), as a non-destructive geophysical technique, was used to assess the existence and depth of existing and infilled scour thickness, streambed materials, and pre- and post- scour surfaces at the bridge piers in Han River, June 2002 and October 2002. The GPR acquisition system used for obtaining profiles of the shallow subsurface deposits was a portable GSSI SIR 2000 system with 100 and 400 MHz antennas. The GPR data obtained along the 24 bridge piers in the flow direction of the river and in the surroundings of 5 bridge piers were compared and presented in this study. It is concluded that GPR surveys can be effective in determining both the water depth and sub-bottom geological structure near the bridge piers and abutments provided that the appropriate instrumentation and operational procedures are applied.