• Journal of the Korean Geophysical Society
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• v.2 no.3
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• pp.179-190
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• 1999

The overall structural framework was studied using the regional 2D seismic data, followed by the sequence stratigraphic study on the 3D seismic and well- log data in the margin of the South Con Son basin of the South China Sea. This research contributes to delineate depositional stratigraphy, depositional environment and geologic history in the 3D seismic area of highly complicated faulting. Eight Miocene sequences were indicated on the 3D seismic and well-log data, in which the structural maps of each sequence boundary and the isochron maps for the corresponding sequence were made. The seismic facies were analyzed for each sequence volume and sequence boundary surface. The 3D seismic area is characterized by coal beds deposited in the transgression environment (transgression systems tract) and channel distributions just above the sequence boundaries. During the Early Miocene, the coals and thick shales deposited in the mangrove swamp representing the lower coastal plain environment. During the Mid to Late Miocene, thick clastic sediments deposited in the coastal to shallow shelf by regional subsidence and marine transgression. The isochron maps and structural patterns indicate that the sediments were transported from west to east or from northwest to southeast.

• Proceedings of the Korea Water Resources Association Conference
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• 2009.05a
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• pp.1678-1682
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• 2009

IRWMS(Integrated Real time Water Management System)은 우리나라의 수자원 운영환경에 부합하도록 하천유역에 수자원 통합관리 개념을 도입한 실시간 물관리 의사결정지원 시스템이다. 국내 기술로 개발하여 실무에 적용함으로써 수자원 이용 효율을 극대화하고 선진국 수준의 수자원 관리기술을 확보하기 위한 방안으로 개발되어졌다. 이러한 물관리 시스템 구축을 위해서는 통합 유역에 적합한 모형의 선택과 이수, 치수, 수질 관리 모델의 통합 방안, 해당 유역특성을 반영한 시스템 구성 방법, 각각의 모형의 입,출력 자료의 관리 및 실무에 적용하기 용이한 GUI 구성 등을 고려하여야 한다. 물관리 시스템은 GIS 기반의 해석모형과 웹기반의 정보, 지식 전달 시스템, 수문자료 관리를 위한 DB시스템 등으로 구성되어져 있으며 SOBEK, RIBASIM, MIKE BASIN, WEAP 등 다양한 물관리 시스템들은 각각의 개발 시기나 쓰임에 따라 해석모형과 DB의 사용유무 등 여러 기능들을 차별화하여 구성하고 있다. RIBASIM(RIver BAsin SIMulation)의 경우 다양한 해석모형 들을 각각의 과정에 따라 사용하고 있으며 CMT(Case Management tool), CAT(Case Analysis Tool)라 불리는 기능들을 통하여 각각의 과정을 순차적으로 진행하고 분석하고 있으며 자사의 수문DB관리 프로그램, 수질, GIS도구 등과 연동하여 사용되고 있다. MIKE BASIN의 경우 ArcGIS의 EXTENSION으로 강력한 GIS기능과 비쥬얼한 화면 구성을 그 특징으로 가지고 있다. IRWMS는 강우유출모형과 댐군 저수지 연계 운영모형, 수질모형으로 구성되어져 있으며 DB와의 연동을 통하여 실시간으로 의사결정자들이 의사결정을 지원하며 실무진 중심의 GUI구성을 통하여 실용성을 중심에 두었다. IRWMS는 금강, 낙동강의 구축사례에서 보듯이 실시간 운영으로 수자원 관리 실무진의 사용에 그 주안점을 두었지만 차후 범용화와 상기에서 언급한 여러 국내외 시스템들의 장점을 받아들인다면 각각의 유역특성에 맞는 다양한 활용으로 수자원기술의 선진화에 크게 기여를 할 것이다.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.4B
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• pp.335-344
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• 2006

In this study, sequential mixing model (SMM) was proposed based on the Taylor's theory which can be summarized as the fact that longitudinal advection and transverse diffusion occur independently and then the balance between the longitudinal shear and transverse mixing maintains. The numerical simulation of the model were performed for cases of different mixing time and transverse velocity distribution, and the results were compared with the solutions of 1-D longitudinal dispersion model (1-D LDM) and 2-D advection-dispersion model (2-D ADM). As a result it was confirmed that SMM embodies the Taylor's theory well. By the comparison between SMM and 2-D ADM, the relationship between the mixing time and the transverse diffusion coefficient was evaluated, and thus SMM can integrate 2-D ADM model as well as 1-D LDM model and be an explanatory model which can represents the shear flow dispersion in a visible way. In this study, the predicting equation of the longitudinal dispersion coefficient was developed by fitting the simulation results of SMM to the solution of 1-D LDM. The verification of the proposed equation was performed by the application to the 38 sets of field data. The proposed equation can predict the longitudinal dispersion coefficient within reliable accuracy, especially for the river with small width-to-depth ratio.

• Proceedings of the Korea Water Resources Association Conference
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• 2023.05a
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• pp.233-233
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• 2023

효율적인 수자원 관리에 필수적인 요소 중 하나는 유역 유출의 정확한 예측이다. 동일한 유역이라 할지라도 과거 기후조건에 대해 매개변수나 모형구조가 최적화된 수문모형은 현재나 미래 기후에 대해 최적이라 할수 없으며, 이에 따라 유역 유출 해석의 불확실성 또한 증가하고 있다. 수문자료동화는 모형의 입력 자료에 따른 불확실성을 줄이고 예측정확도를 향상 시킬 수 있는 방법으로, 수문모형의 상태량이나 매개변수를 업데이트하여 모형 초기 조건의 가능성 높은 추정치를 생성하는 기법이다. 본 연구에서는 국내 댐 상류 유역에 대해 집중형 수문모형과 순차자료동화 기법의 연계 패키지인 airGRdatassim 모형을 적용하여, 앙상블 칼만 필터와 파티클 필터 기법의 수문자료동화 특성을 비교 분석하고, 자료동화와 관련된 하이퍼-매개변수의 불확실성이 수문모의 성능에 미치는 영향을 분석하였다. 자료동화 적용 결과, 두 자료동화 기법 중 파티클 필터에 의한 모의성능이 높았으며 기상강제력 노이즈의 범위, 갱신 대상 상태량 설정, 앙상블 설정 등 수문자료동화의 설정과 관련된 하이퍼 매개변수의 불확실성은 두 기법별 뚜렷한 차이를 보였다. 또한, 본 연구에서는 일단위에서 시단위로 확장한 유량 예측 자료동화의 시험 모의결과 및 앙상블 수문동화기법의 도전과제에 대해서도 논의한다.

• Economic and Environmental Geology
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• v.44 no.6
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• pp.503-511
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• 2011

The Upper Devonian Grosmont Formation in northern Alberta, Canada, underlies the erosion unconformity that formed between the Cretaceous and Upper Devonian. The formation is divided into four units on the basis of intercalated shales and showing a typical shelf environment of shallowing-upward. It was possible to separate four units(LG~UG3), considering the seismic interpretation attributes of polarity, continuity, frequency/spacing and amplitude and showing the reflection characteristics of the medium-high amplitude, medium-low frequency, good continuity, and subparallel reflection events. The formation can be interpreted as shelf or platform, based on in-situ core data. However, it is difficult, only with reflection attributes and features, to recognize the boundaries and sedimentary environment of parasequence. Therefore, we try to interprete by parasequence set in this study. The parasequence set was formed by erosion unconformity with systems tracts. The erosion unconformity can be recognized by facies data and karst, erosional surface. Grosmont carbonate deposits ranging from platform and shelf to shelf slope are; by wedge-shaped strata of characterized by complex sigmoid-oblique progradational configurations, reflecting a depositional history of upbuilding and outbuilding in response to sea-level changes. Most of the sedimentary units is interpreted as platforms under regression and lowstand environments that support is evidences. In particular, shale layer at the basal part of the highstand systems tracts represents the regressive to lowstand of sea level.

• Journal of the Society of Naval Architects of Korea
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• v.33 no.4
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• pp.22-31
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• 1996

An efficient calculation method of pressure acting on a bluff body is developed. The method is applied to assess the containment capability of an oil fence, considering skirt deformation in current. The pressure on the frontal side of the oil fence is determined by analyzing the potential flow, substituting the wake region as a rigid body which has its boundary at the closed separation streamlines. The pressure at the downstream side of the fence, the so called base pressure, is obtained from the existing experimental results. To verify the calculation method, pressure drag of some bluff bodies in an infinite-fluid medium is calculated, which shows good agreement with the experimental results. The deformed shape of the oil fence is obtained by solving, iteratively, the coupled equations governing the flow field and the deformation of the oil fence, respectively. The deformed shape and the decrease of draft of oil fences with different ballast mass in various current conditions are investigated.

• Journal of Korea Water Resources Association
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• v.52 no.8
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• pp.515-529
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• 2019

Geospatial information for river network and watershed boundary have played a fundamental roles in terms of river management, planning and design, hydrological and hydraulic analysis. Irrespective of their importance, the lack of punctual update and improper maintenance in currently available river-related geospatial information systems has revealed inconsistency issues between individual systems and spatial inaccuracy with regard to reflecting dynamically transferring riverine geography. Given that digital elevation models (DEMs) of high spatial resolution enabling to reproduce precise river network are only available adjacent to national rivers, DEMs with poor spatial resolution lead to generate unreliable river network information and thereby reduce their extensible applicabilities. This study first of all evaluated published spatial information available in Korea with respect to their spatial accuracy and consistency, and also provides a methodology and tool to modify existing low resolution of DEMs by means of striation of conventional or digitized river network to replicate input river network in various degree of further delineation. The tool named FSND was designed to be operated in ArcGIS ModelBuilder which ensures to automatically simulate river network striation to DEMs and delineation with different flow accumulation threshold. The FNSD was successfully validated in Seom River basin to identify its replication of given river network manually digitized based on recent aerial photograph in conjunction with a DEM with 30 meter spatial resolution. With the derived accuracy of reproducibility, substantiation of a various order of river network and watershed boundary from the striated DEM posed tangible possibility for highly extending DEMs with low resolution to be capable of producing reliable riverine spatial information subsequently.