• Proceedings of the Korea Water Resources Association Conference
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• 2004.11a
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• pp.1-204
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• 2004

• Proceedings of the Korea Water Resources Association Conference
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• 2007.05a
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• pp.1342-1347
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• 2007

최근 수자원 분야에서 GIS의 활용은 유역의 수리, 수문분석을 위한 모형의 입력자료 생성 및 모의 결과를 가시화, 이에 따른 유역관리 시스템의 구축 등 폭넓게 활용되고 있다. 또한 국가지리정보시스템에 조사를 통해서 수치지형도 및 주제도를 구축, 구축된 자료의 표준화를 실시하고 있는 실정이다. 그러나 수자원 분야에서 GIS를 활용하기 위한 기술은 주로 선진국을 중심으로 발전하여 왔기 때문에 우리의 실정에 맞지 않아 활용측면에 있어 신뢰할 만한 결과를 얻지 못하고 있는 실정이다. 따라서 국내 상황을 고려하면서 수자원이라는 전문분야 적용에 적합한 GIS(HyGIS)를 개발하고 여기에 수리, 수문분석모형을 연계하여 국내 실무분야에 적용함에 있어 편의성과 실용성을 구비한 모형개발이 이루어져야 한다. 따라서 본 연구에서는 국내 소프트웨어 GeoMania(HyGIS)에 의한 GIS 정보처리의 자동화를 기반으로 하여 실무에서 활용도가 높은 수문모형인 HEC-HMS 및 HEC-1과 수리모형인 HEC-RAS를 연계 및 통합하기 위해서 HyGIS에서 DLL형태로 제공되도록 하였다. HyGIS에서는 수문학적 DEM 분석 및 공간정보 생성, 선형참조가 가능한 하천 네트워크 생성, 유역 시설물 관리 등의 기능을 제공하며 COM(Component Object Model)을 기반으로 개발된 시스템으로 다른 소스로부터 개발된 컴포넌트를 연계하여 시스템의 기능 확장을 손쉽게 수행할 수 있도록 하였을 뿐만 아니라 공간 DB는 GeoMania의 고유 DB인 GSS를 이용한다. HyGIS-HMS는 HyGIS를 통한 국내 유역의 지리정보를 활용하여 HEC-HMS 뿐만 아니라 HEC-1을 추가하여 사용자의 기호와 편의에 따라 모형을 선택할 수 있도록 하였으며 HEC-1의 결과를 가시화하기 위해서 챠트 기능을 추가하였으며 매개변수를 자동으로 산정할 수 있도록 시스템을 구축하였다. HyGIS-RAS는 국내 하천유역에 대해서 기구축 되어있는 하천관리지리정보시스템(RIMGIS)자료를 직접 활용하도록 구성되어있고 자료를 활용하여 제내지와 제외지를 통합하여 TIN분석을 실시하여 범람 홍수해석에 활용할 수 있도록 하였다. 하천수리해석의 기능을 보강하기 위해 역산조도계수 산정모형, 상류-사류 천이류 구간에 대한 부등류 해석모형, 범람 홍수류에 대한 홍수위 산정모형, 하천수리계산시의 불확실도 해석모형 등의 새로운 기능을 추가하여 제시하였다. 모든 입출력자료는 프로젝트 단위별로 운영되어 data의 관리가 손쉽도록 하였으며 결과를 DB에 저장하여 다른 모형에서도 적용할 수 있도록 하였다. 그리고 HyGIS-HMS 및 HyGIS-RAS 모형에서 강우-유출-하도 수리해석-범람해석 등이 일괄되게 하나의 시스템 내에서 구현될 수 있도록 하였다. 따라서 HyGIS와 통합된 수리, 수문모형은 국내 하천 및 유역에 적합한 시스템으로서 향후 HydroInformatics 구현을 염두에 둔 특화된 국내 수자원 분야 소프트웨어의 개발에 기본 토대를 제공할 것으로 판단된다.

• Journal of Korea Water Resources Association
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• v.36 no.6
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• pp.911-924
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• 2003

Many researches have been conducting on extracting geometry data and hydrologic parameters by using GIS technique. However, there is no clear standard on those methods yet. This study examines the changing pattern of runoff responses characteristics with applying lumped model on divided watershed. WMS is used in order to divide watershed and calculate hydrologic geometry data and parameters by GIS technique. HEC-1 is adopted as a hydrologic model to establish runoff responses. The basin is divided into small watersheds, which are approximately same size. This research conducted runoff response simulation of Pyoungchang River and Wichon River Basin. Especially, research was focused on what is the most appropriate level as a divined sub-basin, and tested the effect of size of sub-basin for the runoff response simulation. The results showed the size of sub-basin was not an important factor for the simulation results after a certain size. The results of this study can be applied as an appropriate guidance to select optimal simulation size of watershed for the lumped model in a specific watershed.

• Journal of Korea Water Resources Association
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• v.38 no.7 s.156
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• pp.555-564
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• 2005

In this study, a simple rainfall-runoff model was proposed by using the hydraulic routing model that requires relatively few parameters. The parameters of this model were estimated by the watershed characteristics data, and were applied to the Soyang watershed and Ui stream watershed by using the kinematic wave for overland flow and dynamic wave routing for channel routing. In order to demonstrate validity, the proposed approach was compared to the HEC-1 model for the Soyang watershed. As the results of modeling have shown, the hydraulic model shows reasonable results similar to that of the HEC-1 model. This model also represents good results for the Ui stream watershed. Hence, even if this model is a simple rainfall-runoff model using general methodology, it is competitive to the natural watershed. However, it is still difficult to estimate the roughness coefficient and the catchment width, and therefore this model is in need of such supplements.

• Journal of The Korean Society of Agricultural Engineers
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• v.52 no.6
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• pp.63-73
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• 2010

This study is to develop a downstream flood damage prediction model for efficient confrontation in case of extreme and flash flood by future probable small agricultural dam break situation. For a Changri reservoir (0.419 million $m^3$) located in Yongin city of Gyeonggi province, a dam break scenario was prepared. With the probable maximum flood (PMF) condition calculated from the probable maximum precipitation (PMP), the flood condition by dam break was generated by using the HEC-HMS (Hydrologic Engineering Center - Hydrologic Modeling System) model. The flood propagation to the 1.12 km section of Hwagok downstream was simulated using HEC-RAS (Hydrologic Engineering Center - River Analysis System) model. The flood damaged areas were generated by overtopping from the levees and the boundaries were extracted for flood damage prediction, and the degree of flood damage was evaluated using IDEM (Inundation Damage Estimation Method) by modifying MD-FDA (Multi-Dimensional Flood Damage Analysis) and regression analysis simple method. The result of flood analysis by dam-break was predicted to occurred flood depth of 0.4m in interior floodplain by overtopping under PMF scenario, and maximum flood depth was predicted up to 1.1 m. Moreover, for the downstream of the Changri reservoir, the total amount of the maximum flood damage by dam-break was calculated nearly 1.2 billion won by IDEM.

• Korea-Australia Rheology Journal
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• v.14 no.4
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• pp.189-201
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• 2002

The interaction between hydrophobically modified hydroxyethyl cellulose (hmHEC), containing approximately 1 wt% side-alkyl chains of $C_{16}$, and an anionic sodium dodecyl sulphate (SDS) surfactant was investigated. For a semi-dilute solution of 0.5 wt% hmHEC, the previously observed behaviour of a maximum in solution viscosity at intermediate SDS concentrations, followed by a drop at higher SDS concentrations, until above the cmc of surfactant when the solution resembles that of the unsubstituted polymer, was confirmed. Additionally, a two-phase region containing a hydrogel phase and a water-like supernatant was found at low SDS concentrations up to 0.2 wt%, a concentration which is akin to the critical association concentration, cac, of SDS in the presence of hmHEC. Above this concentration, SDS molecules bind strongly to form mixed micellar aggregates with the polymer alkyl side-chains, thus strengthening the network junctions, resulting in the observed increase in viscosity and elastic modulus of the solution. The shear behaviour of this polymer-surfactant complex during steady and step stress experiments was examined In great detail. Between SDS concentrations of 0.2 and 0.25 wt%, the shear viscosity of the hmHEC-polymer complex network undergoes shear-induced thickening, followed by a two-stage shear-induced fracture or break-up of the network. The thickening is thought to be due to structural rearrangement, causing the network of flexible polymers to expand, enabling some polymer hydrophobic groups to be converted from intra- to inter-chain associations. At higher applied stress, a partial local break-up of the network occurs, while at even higher stress, above the critical or network yield stress, a complete fracture of the network into small microgel-like units, Is believed to occur. This second network rupture is progressive with time of shear and no steady state in viscosity was observed even after 300 s. The structure which was reformed after the cessation of shear is found to be significantly different from the original state.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.8
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• pp.5716-5720
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• 2015

This study has analyzed the backwater effect by the bridge pier on the basis of the result on hydraulic characteristics with pier shapes in study(I), using a two-dimensional model(RMA-2) and an one-dimensional model(HEC-RAS). The pier shapes are classified into total six types such as square, rhombus, octagon, oval, round, and no-piers. The result of the backwater effect analysis showed that the backwater length is about 150 and 50m from HEC-RAS and RMA-2, respectively for all pier types. Although it is difficult to directly compare between results from the two models, the oval shape pier has shown similar results to the no-pier situation before the bridge construction in hydraulic characteristics. This analysis can help to select pier types in the new bridge construction for the future.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.22 no.12
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• pp.2727-2735
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• 1997

This paper describes a new fading compensation scheme for Wireless ATM(WATM) sytem using pilot symbols. We have carried out a simulation for bit error rate(BER) and cell loss probability(CLP) to analyze the performance of a new scheme. As the resutls, BER performance we improved by means of HEC only above 3 dB of $E_{b}/N_{0}$ in AWGN, but not at all in fading environment. However, by using a new fading compenstion scheme with HEC, BER performance degraded below to 1 dB of $E_{b}/N_{0}$ in AWGN, but BER and CLP performances in WATM system were improved remarkably, and meeted at CLP performance criterion for K=10 dB rician fading. Also, code rate will be high and harware size of codec will be small by using this new scheme with HEC OR FEC.

• Proceedings of the Korea Water Resources Association Conference
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• 2021.06a
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• pp.411-411
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• 2021

최근 들어 이상기후에 따른 집중호우의 영향과 하천 유역 내에서의 토지이용의 증가로 하천의 하류부에서의 홍수피해는 점점 증가하고 있다. 이에 대비하기 위해 하천 시설물 설치를 계획하거나 이수, 치수 계획을 세우기 위해서는 하상이 어떻게 변화할 것인지 파악하는 것이 중요하다. 연구 대상 지역 세종특별자치시 금남면 영대리 유천천은 최근 10년간 홍수로 인한 피해액이 연평균 약 2.4억 원으로 나타났으며 매년 피해가 지속되고 있다. 유천천은 인위적 하도의 변경과 토지이용 상황의 변화 및 하천 골재채취, 댐 및 저수지 건설, 자연적인 홍수 등으로 하상이 변동되고 있으며, 그로 인해 생긴 유로의 변화로 발생할 수 있는 피해 예측이나 하천 시설물 설치를 위해서는 변동 결과의 예측이 필요하다. 따라서 본 연구에서는 대상 유역의 하상변동을 분석하기 위하여 HEC-RAS Sediment Transport Analysis(STA) 모형을 적용하였다. 적용한 데이터를 바탕으로 장래 하상변동 결과를 예측하였고 GIS 기법을 이용하여 유역의 특성 및 유출 특성에 관한 인자들을 도출하였다. 장래 1년, 5년, 10년 단위로 하상변동의 예측이 가능한 HEC-RAS STA 모형 분석 결과, 하상경사가 급한 각 하천상류 구간과 횡단시설물의 상류층에서는 하상저하가 발생하고, 하상경사가 완만한 하류 구간 부근에서는 일부 하상 상승이 발생하는 것으로 나타났다. 수위상승에 대비하여 지속적인 관찰과 상승구간에 대한 주기적인 하천 정비를 통하여 홍수기에 수위상승을 억제할 필요가 있을 것으로 판단된다. 본 연구의 결과는 하도 안정성과 이수와 치수안정성 확보, 하천의 효율적인 이용과 보전, 유지관리 시 기본해석으로 활용할 수 있을 것으로 사료된다.

• Proceedings of the KSRS Conference
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• v.2
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• pp.602-605
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• 2006

This study is to apply QuickBird satellite image for the simulation of storm runoff in a small rural watershed. For a 1.05 $km^2$ watershed located in Goesan-Gun of Chungbuk Province, the land use from the QuickBird image was produced by on-screening digitising after ortho-rectifying using 2 m DEM. For 3 cases of land use, soil and elevation scale (1:5,000, 1:25,000 and 1:50,000), SCS (Soil Conservation Service)-CN (Curve Number) and the watershed physical parameters were prepared for the storm runoff model, HEC-HMS (Hydrological Modelling System). The model was evaluated for each case and compared the simulated results with couple of selected storm events.