• Title/Summary/Keyword: alluvial deposits

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Electrical and Hydrological Properties of Alluvium (충적층(沖積層)의 투수성(透水性)과 지하수(地下水)의 전기탐사(電氣探査)에 대(對)하여)

  • Jin, Doo Jung
    • Economic and Environmental Geology
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    • v.1 no.1
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    • pp.70-73
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    • 1968
  • In Korea, ground water exploration by the electric method as a major prospecting tool has been carried out mainly in alluvial deposits, So it is considered to be important to understand the principle concerning the electrical and hydrological properties of alluvium. Factors which affect on the electrical and hydrological properties of alluvium were investigated. Major elements in ground water exploration are porosity and dermeability for most alluvial deposits with exceptions in some particular areas. Much water yield can be expected where alluvial materials have large porosity and small particle size while large particle size in necessary for good permeability. Problem is to locate the points which have comparatively large porosity and good permeability at a time. It is known that electrical resistivity method is proved useful to solve the above problem. The conclusion is: Localities which have greater alluvium thickness(7 to 10m) and 200 to 500 ohm -m of real resistivity value are suitable for well site in alluvial deposits in Korea where alluvium thickness is comparatively small(less than 10m in generaa) and bedrock formations are mainly composed of granite gneiss and granite.

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A Study on the Precise Lineament Recovery of Alluvial Deposits Using Satellite Imagery and GIS (충적층의 정밀 선구조 추출을 위한 위성영상과 GIS 기법의 활용에 관한 연구)

  • 이수진;석동우;황종선;이동천;김정우
    • Proceedings of the Korean Association of Geographic Inforamtion Studies Conference
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    • 2003.04a
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    • pp.363-368
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    • 2003
  • We have successfully developed a more effective algorithm to extract the lineament in the area covered by wide alluvial deposits characterized by a relatively narrow range of brightness in the Landsat TM image, while the currently used algorithm is limited to the mountainous areas. In the new algorithm, flat areas mainly consisting of alluvial deposits were selected using the Local Enhancement from the Digital Elevation Model (DEM). The aspect values were obtained by 3${\times}$3 moving windowing of Zevenbergen & Thorno's Method, and then the slopes of the study area were determined using the aspect values. After the lineament factors in the alluvial deposits were revealed by comparing the threshold values, the first rank lineament under the alluvial deposits were extracted using the Hough transform In order to extract the final lineament, the lowest points under the alluvial deposits in a given topographic section perpendicular to the first rank lineament were determined through the spline interpolation, and then the final lineament were chosen through Hough transform using the lowest points. The algorithm developed in this study enables us to observe a clearer lineament in the areas covered by much larger alluvial deposits compared with the results extracted using the conventional existing algorithm. There exists, however, some differences between the first rank lineament, obtained using the aspect and the slope, and the final lineament. This study shows that the new algorithm more effectively extracts the lineament in the area covered with wide alluvlal deposits than in the areas of converging slope, areas with narrow alluvial deposits or valleys.

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Boundary/Finite Element Analysis of the Seismic Wave Amplifications due to Nonhomogeneous Alluvial Deposits (비균질 퇴적층으로 인한 지진파 증폭의 경계/유한요소 해석)

  • 김효건;손영호;김종주;최광규
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 1998.10a
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    • pp.463-470
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    • 1998
  • The boundary/finite element analysis for the seismic wave amplifications due to nonhomogeneous alluvial deposits was performed in this study. For numerical analysis, the homogeneous linear elastic soil half-space was modeled by using the 3-node isoparametric boundary elements and the inhomogeneous alluvial deposit was modeled by using the 8-node isoparametric finite elements. The two elements at interface were coupled together by the equilibrium condition of the tractions and the compatibility condition of the displacements. As a prarmetric variable, the incident angle and the dimensionsless frequency of the SH, P and SV-waves and the shear wave velocity ratio and the mass density ratio between the half-space and the alluvial deposit were selected.

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The Irrigation and Drainage Systems of Coastal Alluvial Plain: Sand Dune Area and Allurial Plain in Bulgap River Catchment in South Jeolla Province (소규모 임해충적평야의 수리체계 -불갑천 하류의 충적지와 해안사구를 중심으로-)

  • Kahng Taygyoon
    • Journal of the Korean Geographical Society
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    • v.39 no.6 s.105
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    • pp.863-872
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    • 2004
  • The coastal alluvial plain, sand dune, tidal nat might be the most prominent coastal landscape in western coast of Korea. The purpose of this paper is to examine the irrigation and drainage systems of the alluvial plain in the tidal coast. This study is concerned on the geomorphological and cultural landscapes of the alluvial plain in the western coast of the South Jeolla Province. The alluvial deposits have developed mainly by the actions of tidal currents, rather than transporting sediments by stream. The transformation of plain has been affected by human agency since 1920's. Dwellers have constructed the reservoir, banks, dammed pools, lock gates, and tide-dykes for the reclamation, irrigation, and drainage on the alluvial plain, coastal sanddune, and tidal flats.

Channel-fill Deposits of Gravel-bed Stream, Southeastern Eumsung Basin (Cretaceous), Korea

  • Ryang, Woo-Hun
    • Journal of the Korean earth science society
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    • v.27 no.7
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    • pp.757-767
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    • 2006
  • Alluvial-plain deposits in the southeastern part of the Eumsung Basin (Cretaceous) are characterized by coarse-grained channel fills encased in purple siltstone beds. It represents distinct channel geometry, infill organization, and variations in facies distribution. The directions of paleocurrent, sedimentary facies changes, and channel-fill geometry can be used to reconstruct a channel network in the alluvial system developed along the southeastern margin of the basin. The channel-fill facies represent downstream changes: 1) down-sizing and well-sorting in clast and martix of channel fills and 2) internal organization of scour fill or gravel lag and overlying cross-stratified, planar-stratified beds. These findings suggest multiple stages of channel-filling processes according to flooding and subsequent stream flows. In the small-scale pull-apart Eumsung Basin (${\sim}7{\times}33km^2$ in area), vertical-stacked alluvial architecture of the coarse-grained channel fills encased in purple siltstone is expected to result from episodic channel shifting under a rapidly subsiding setting.

Sedimentary Facies and Geomorphological Development of Alluvial Plain at Neungsan-ri, Buyeo, Korea (부여 능산리 충적평야 퇴적상과 지형발달)

  • Yoon, Soon-Ock;Kim, Ae-Sun;Hwang, Sang-Ill
    • The Korean Journal of Quaternary Research
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    • v.24 no.1
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    • pp.35-45
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    • 2010
  • The aims of this study are to clarify the geomorphological development of a alluvial plain and discuss the vegetation environments and agriculture activities in the Wangpo-River alluvial plain at Neungsan-ri, Buyeo by analyzing geomorphological classification, sedimentary facies and age datings. The alluvial plain at Wangpo-River was formed by the influences of Geum-River with the sea-level rising during the Holocene. The basin of Wangpo-River consists of natural levees, back marsh-type alluvial plains, valley plains and hills. The natural levees by Geum-River largely distributes at the area where Wangpo-River flows to Geum-River and the alluvial plains at the middle and lower reach are the back marsh areas of Geum-River. Moreover, the area along Wangpo-River show higher contents of coarse materials and thinner peat sediments than the back marsh. The lower sandy deposits in the alluvium of Wangpo-River was formed with the influences of human in the Bronze Age during the sea level falling and the peaty deposits was formed due to the water level rising of Wangpo-River during the sea level rising in the early Iron Age.

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Delineation of internal heterogeneities of Geum River point bar deposits in Buyeo area using GPR Data (지하 투과 레이다 조사를 통한 부여 지역 금강변의 충적 대수층 내부 불균질성 파악)

  • Rhee, Chul-Woo;Kim, Hyoung-Soo;Lee, Kyung-Joo
    • Journal of the Korean Geophysical Society
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    • v.5 no.4
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    • pp.337-344
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    • 2002
  • The alluvial deposits along meandering rivers can be used as an artificial aquifer for infiltration of river waters. Internal heterogeneity of the alluvial deposits is a prerequisite information for the development of alluvial groundwater because vortical and lateral movement of alluvial ground water depends on the internal heterogeneity The internal heterogeneity due to variations in channel behavior can be delineated using GPR survey, GPR profiles for the point bar deposits near Buyeo county reveals two different stratigraphic units: the lower inclined heterogeneous strata and the upper horizontally stratified strata. The upper unit is largely indicative of vertical accumulation by overbank floods within a floodplain, whereas the lower one represents typical point bar deposits formed by lateral accretion. The stratigraphic variation in the heterogeneity shows that GPR survey is a useful and necessary investigation method for the development of alluvial ground water.

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Development of Technology on Water Thermal Energy Utilization of Riverbank(including Alluvial and Riverbed deposits) Filtration (강변여과수(충적층 및 하상) 열자원 활용 기술 개발)

  • Kim, Hyoung-Soo;Seo, Min-Woo;Jung, Woo-Sung;Song, Yoon-Ho
    • 한국신재생에너지학회:학술대회논문집
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    • 2005.11a
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    • pp.591-594
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    • 2005
  • Geothermal energy becomes to be one of the promising energy sources. In this study, technology using water thermal energy from riverbank filtration system(including alluvial and riverbed deposit) is reviewed and checked as an energy resources. The objects of this study are (1) long-term monitoring of alluvial and riverbed sites, (2) preliminary design of cooling and heating system at riverbank filtration facility, and (3) calculation of potential groundwater heat energy, including riverbank filtration system. Measuring data of alluvial and riverbank filtration show slight fluctuations comparing to temperature of atmospheric air which indicates that groundwater obtained from the riverbank filtration system have a sufficient potential as a source of cooling and heating energy.

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Constitutive Relation of Consolidaion for Marine Clay (해성점토의 압밀구성관계)

  • 차경섭
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.42 no.3
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    • pp.89-96
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    • 2000
  • Most soft ground in the southern and western coasts in Korea consists of very compressible alluvial deposits. Four samples in these alluvial deposite were selected to manifest the constitutive relations of consolidation. A series of tests were performed to investigate void ratio -effective stress relationand void ratio-coefficient of permeability relation on soil samples obtained at Haenam. Jindo Mankyung and Janghung permeabilities by CRS thoery were similar to directly measured data but those of indirectly computed by $C\upsilon$ shows difference. Several models about compressibility and permeability were compared with test data.

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Tunnelling on terrace soil deposits: Characterization and experiences on the Bogota-Villavicencio road

  • Colmenares, Julio E.;Davila, Juan M.;Shin, Jong-Ho;Vega, Jairo
    • Geomechanics and Engineering
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    • v.15 no.3
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    • pp.899-910
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    • 2018
  • Terrace deposits are often encountered in portal areas and tunnels with low overburden. They are challenging to excavate considering their great mechanical and spatial heterogeneity and a very high stiffness contrast within the ground. Terrace deposits are difficult to characterize, considering that samples for laboratory testing are almost unfeasible to obtain, and laboratory tests may not be representative due to scale effects. This paper presents the approach taken for their characterization during the design stage and their posterior validation performed during construction. Lessons learned from several tunnels excavated on terrace deposits on the Bogota-Villavicencio road (central-east Colombia), suggest that based on numerical simulations, laboratory testing and tunnel system behaviour monitoring, an observational approach allows engineers to optimize the excavation and support methods for the encountered ground conditions, resulting in a more economic and safe construction.