• Journal of The Korean Society of Agricultural Engineers
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• v.56 no.4
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• pp.77-82
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• 2014

In Korea, length of irrigation and drain canal is about 98,638 km. In the case of 2011, dredging on the irrigation and drain canal was 7,288 km about 3,290,483 $m^3$, cost of dredging was about 5.6 billion won and cost of dredging increases every year. (Korea Rural Community Corporation, 2013). In the case of land reclamation, the problem of cross-contamination due to leachate after landfill is expected, causing saturation of the landfill site, or complaints of landfill local residents, a number of problems. The ocean landfill is possible if the items of 14 types as defined in the Sea Pollution Prevention Law contained in sediment soil, such as chromium. In terms of cost and labor, it is need to develop a technology utilizing a processing method reasonable sediments for irrigation and drainage canal. The objective of this study was to analyze the characteristics of the sediment deposited on the irrigation and drain canal. it is to provide basic data for the scheme that can be efficiently recycled sediment deposited on the irrigation and drain canal.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.4 no.1
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• pp.49-58
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• 1984

This paper is to exhibit the numerical analysis of sediment transport in the slowly varing flow and the sediment transport relation between the steady and the unsteady flow in the alluvial stream. The gradually varied flow of alluvial stream and the sediment transport are very complicated physical phenomen. Therefore the mathematical modeling is needed to be established. Linear implicit means of modified indirect method are applied to sediment transport by numerical analysis instead of the conception of steady flow in order to decrease errors. Further more, this study has purpose on reasonable prediction of the river-bed variation by way of this numerical method.

• Proceedings of the Korea Water Resources Association Conference
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• 2006.05a
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• pp.1535-1540
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• 2006

하천의 평형상태를 판단하기위해 필요한 두가지 관점은 첫째, 대상 하천이 현재 평형상태에 있는 가이고 둘째, 하천에 하상변동을 일으킬 수 있는 인위적인 영향을 가한 후에 하천반응을 통해 궁극적으로 결정되는 평형상태를 예측하는 것이다. 따라서 본 연구는 하도의 특성을 토대로 하여 현 하도의 평형상태를 정성적인 측면에서 검토하고, 흐름과 유사 이송에 관련된 수학모형을 수치적으로 해석하는 하상변동모형의 분석을 통한 현하도의 안정성 및 하상변동 양상을 파악하는데 그 목적이 있다. 본 연구는 임진강 유역의 충적하천인 문산천을 대상으로 지배유량을 산정한 후 지배유량 유하시의 마찰속도와 무차원 소류력 등의 하도특성량을 산정하여 토사이송이 크게 발생하는 구간을 정성적으로 예측하였다. 예측된 구간의 현장조사결과 $No.29{\sim}No.35$ 구간의 하상의 상승은 개수공사와 수해복구공사로 인한 인위적인 굴착에 대한 퇴적으로 하천이 평형상태로 환원하고자 하는 것으로 판단되었고, $No.41{\sim}No.54$ 구간의 하상저하는 문산천 상류구간의 큰 하상경사와 보의 영향인 것으로 조사되었다. 또한 1, 2차원 모형에 의한 장 단기 하상변동 분석결과 하도특성량을 이용한 하도의 안정성 평가와 유사한 결과를 보였다. 따라서 문산천의 경우 하상변동의 양상 파악 및 하도의 안정성 판단을 하는데 있어 하도특성량을 근거로 판단하는 방법의 적용가능성을 파악할 수 있었다.

• Journal of Korean Society on Water Environment
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• v.22 no.6
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• pp.1094-1100
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• 2006

In this study, the reservoir sediment reduction methods for long-term operation are proposed by the analysis of both sediment deposit characteristics and sediment reduction effect by each method. To that end, a flowchart for sediment analysis in reservoir is established and sediment deposit is simulated by SMS-SED2D model. The sediment reduction methods which are sediment passing (sluicing), flushing, trapping, bypassing and mechanical removal are used. From the simulation results, the effective method for sediment reduction is operation which is coupled by both sediment passing with sand gate and sediment trapping with debris dam. And If sediment flushing will be used once a year after 50 years, conservation storage can be secured until 100 years after dam construction.

• Water for future
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• v.27 no.2
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• pp.63-72
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• 1994

In this study, hydraulic characteristics for upstream migration of fish in a pool-and-weir fishway were analyzed through experiment. The results showed that streaming flow was preferable to plunging flow for upstream migration of fish and it was not good to make an orifice beneath the septum since it generates turbulent jet and eddies. Protrusions on the side wall of fishway were preferable to grooves since they decelerate flow velocity and make upstream migration easy. A vertically movable septum was necessary for a flushing of deposited bed material, and net installing over fishway was also needed for birds not to approach the fishway and eat fish.

• Water for future
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• v.21 no.1
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• pp.87-94
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• 1988

Tidal asymmetry in the Keum River Estuary has been investigated from the observed tides. Despite strong frictional attenuation within the estuary, the $M_4$ tides reach significant amplitude, resulting in strong tidal distortion. The observed asymmetry over the area shows that generally more intense flood flows transport more sediment that do less intense ebb flows of longer duration. This causes filling of the estaury as evidenced by sand flats spreaded over the inner area. The spatial distribution of peak bottom stress associated with the dominant $M_2$ and $M_4$ tides calculated via two-dimensional numerical tidal model suggest that present tidal sedimentation regimemay be altered, sepecially in the approach channel to outer Kunsan Port and downstream part of the dike, due to the construction of barrier.

• Journal of The Korean Society of Agricultural Engineers
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• v.56 no.6
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• pp.121-128
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• 2014

Development of the economic methods and the design of the standard sections needs the more project fund and land than ever leads to the objection of enlarging canal arrangement to need economic construction method development and standard design for supporting it. The objective of this study was to evaluate the performance of selected sediment reduction methods to reduce sediment discharges from drain and irrigation of different land types (Mountain, Flatten, Reclaimed land). This study was carried out to analysis for the soil loss and sediment of drain and irrigation by comparing RUSLE method and amount of sediment from amount of dredging data of Korea Rural Corporation. The results of study were analyzed and summarized as follow. Size of soil sediment from the upper region of drain and irrigation of mountains bigger than lower region. But in case of flatten and reclaimed land, size of soil sediment from the upper and lower region of drain and irrigation did not classified. In case of comparison drain and irrigation without classifying of land type, size of soil sediment from irrigation is bigger than drain.

• Journal of the Korean Society of Hazard Mitigation
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• v.9 no.2
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• pp.53-57
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• 2009

The dividing flow in an open channel has a number of distinctive characteristics. One of these is that the separation zone interacts with a secondary motion along the inner wall of a branch channel, generating sediment accumulation. To investigate this phenomenon, a two-dimensional numerical model based on the shallow-water equations, RMA2, which calculates water surface elevations and horizontal-velocity components, was used to analyze the dividing flow. The obtained numerical results fully coincide with the laboratory measurements reported by Hsu et al.(2002). For the analysis of the numerical results, a separation zone-discharge rate relationship was proposed. To reduce the size of a separation zone, the topographies of diagonal and curved edges were proposed, smoothly connecting the upstream corner to branch channel.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.15 no.2
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• pp.127-137
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• 2003

The researches on the construction of artificial coastal wetlands have been progressed in order to cope with the situation that the area of Korean tidal flat has been reduced due to several coastal developments This study, as a part of the project on construction of the artificial tidal flats, deals with the comparison of the geotechnical characteristics between natural tidal flat and artificial tidal flat, and is also focused on the stability analysis of tidal flats. Various laboratory tests were performed using disturbed and undisturbed samples, which were obtained from a sandy tidal flat in Korea. The stability of the sandy soils accumulated on the tidal flat was investigated by comparing the shear strength of soil evaluated from laboratory test with induced shear stress due to both current and wave action.

• Proceedings of the Korea Water Resources Association Conference
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• 2015.05a
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• pp.302-302
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• 2015

본 연구에서는 PMP 조건하에서 농업용 목적의 시례저수지의 가상붕괴에 따른 홍수파 해석을 통해서 하류부에 대한 수리학적 분석을 실시하였다. 그리고, 사력댐으로 구성된 댐 제체의 붕괴로 인한 유사 이송을 모의하고 이로 인한 하류부에서의 영향을 분석하였다. 이를 위하여 경상남도 김해에 위치한 시례저수지 유역을 대상으로 수리 수문자료 및 하천현황을 상세히 조사하고 댐의 가상 붕괴로 인한 하류부 홍수파 해석 및 댐 본체의 유실에 따른 유사의 이송으로 인해 발생 가능한 하류부에서의 영향을 분석하였다. 시례저수지의 댐 형식은 흙댐으로써, 구성방식은 침하량이 적은 중심코아형이며 댐 높이는 34.3 m, 유역면적은 3.13 km이다. 본 연구에서는 하천에서의 흐름과 유사이송 계산이 가능한 1차원 수치 모형인 CCHE1D를 이용하였다. 적용 모형은 확산파 및 동역학적 방정식을 모두 고려한다. 또한, 비평형 이송 모형을 사용하여 유사의 발생과 퇴적을 산정하고 비균질 상태의 유사 이송을 계산 하는데 있어서 하천 단면형의 변화와 하상물질의 구성 상태, 제방침식, 수로 확폭의 과정과 함께 산정된다. CCHE1D는 하상물질의 공극률과 non-equilibrium adaptation length, mixing layer thickness 등의 여러 변수들을 현재까지 개발된 식들을 제공하며, 토사이동해석을 위한 공식은 SEDTRA 모듈, Wu et al(2000) 공식, 수정 Ackers and White(1973) 공식, 수정 Engelund and Hansen(1967)이 사용된다. 비균질 유사이송과 bed deformation, bed-material sorting은 완전연계과정(coupling)로, 유사와 흐름방정식의 계산은 반연계과정(semi coupling)을 적용하여 계산하였다.