• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.4
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• pp.726-733
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• 2016

Recently, the flood frequency and magnitude have increased due to heavy rainfall. Considering the present condition, a flood risk map has been published in many countries to raise awareness about flood damage to people. A flood inundation analysis model, which is used to publish the flood risk map, can be classified as river and inland inundation models according to the inundation cause. Although a variety of flood inundation analysis models are utilized both domestically and overseas, their usability is limited by the expensive price, except for the HEC-RAS model developed by U.S. Army Corps of Engineers (USACE). In the situation, the USACE has developed a 2-D HEC-RAS model that can be linked to the existing 1-D model. This model has been released as a beta version under the name, HEC-RAS 5.0. In this study, the HEC-RAS 5.0 model's features, usability, applicability, and accuracy were evaluated by comparing the performances on Gokgyo-cheon with the FLUMEN model, which is used for domestic flood risk mapping. The results of this study will contribute to river inundation analysis in many different ways after the HEC-RAS 5.0 model is stabilized.

• Journal of Environmental Science International
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• v.13 no.9
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• pp.759-765
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• 2004

HEC-RAS model is used for estimation of rating-curve of Musung in Wi stream. Discharge is computed from stage estimated by HEC-RAS model, is compared with the discharge of water surface slope method. The relative deviation of observed and computed discharge is 5.37%, and shows as a good results. A rating-curve by HEC-RAS model shows better results than by water surface slope method.

• Water for future
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• v.50 no.3
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• pp.45-51
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• 2017

• Proceedings of the Korea Water Resources Association Conference
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• 2009.05a
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• pp.1078-1083
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• 2009

HEC-HMS(Hydrologic Modeling System)은 강우-유출 모의를 위한 차세대 소프트웨어이며 HEC-1에 포함되어 있는 단위도 및 수문학적 홍수추적 이외에도 격자형 강우자료(레이더 데이터)를 이용하여 적용할 수있는 유사분포 유출변화와 장기 연속모의에 적용할 수 있는 간단한 수분감소 등을 추가적으로 포함하고 있다. 또한 GUI(Graphical User Interface)환경, 통합 수문분석 성분, 자료 저장 및 관리 능력, 그래�d 처리 및리포트 출력기능으로 구성되어 있으며 여러 가지 프로그램 언어(C, C++, Fortran)를 이용하여 개발되었다. 본 연구에서는 낙동강 수계의 금호강에 위치한 동촌 지점을 유출구로 선정하고 5개의 소유역과 두 개의 하도로 구성하여 유출모의를 실시하였으며 수문자료 선정은 2007년$^{\sim}$2008년에 발생한 홍수사상과 유량조사 사업단에서 개발한 수위-유량관계곡선식을 활용하였다. 또한, HEC-GeoHMS 모형을 GIS와 연계하여 지형인자를 추출하고 추출된 지형인자를 이용하여 매개변수를 산정하였다. HEC-HMS 모형의 계산 조건에서 손실 우량은 SCS CN, 유출변환은 Clark 단위도법을 적용하였다. 또한 관측치와 계산치의 적합도 검증은 평균제곱 근오차(root mean squar error; RMSE)와 모형 효율성 계수(model efficiency; ME)를 산정하여 분석하였다

• Journal of Life Science
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• v.21 no.6
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• pp.829-837
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• 2011

The purpose of this study was to investigate the effects of ethanol extracts from red pepper seeds on cholesterol adsorption capacity and UDP-glucuronyl transferase activity. In vitro cholesterol adsorption capacity of 2%, 5% and 10% ethanol extracts from red pepper seed groups were significantly higher than that of the control group. Sprague-Dawley strain male rats weighing $100{\pm}10$ g were randomly assigned to one normal diet N group and experimental groups fed high fat and high cholesterol diet, which were divided into HF (0.0%), HEA (0.1%), HEB (0.2%), and HEC (0.5%) groups according to the amount of ethanol extracts from red pepper seeds added to their basal diet. The body weight gain in the HF group was higher than that in the N group, and those in the HEA, HEB and HEC groups were lower than that in the HF group However, there were no statistically significant differences among the all the groups. The hepatic triglyceride and total cholesterol contents in the N group was significantly lower than that in the HF group, and those in the HEA, HEB and HEC groups were lower than that in the HF group. The hepatic UDP-glucuronyl transferase activity in the N group was lower than that of the HF group and those in the HEA, HEB and HEC groups were lower than that of the HF group. The serum total cholesterol and triglyceride contents of the HF group were significantly higher than that of the N group, and those of the HEA, HEB and HEC groups were lower than that of the HF group. The serum HDL-cholesterol contents in all groups supplemented with the ethanol extracts from red pepper seeds were significantly higher than that of the HF group. The serum LDL-cholesterol contents of the HF group were significantly higher than that of the N group, and those of the HEA, HEB and HEC groups were lower than that of the HF group. The fecal total cholesterol contents were significantly higher in the HF group compared to the N group, and those of the HEB and HEC groups were lower than that of the HF group. The fecal triglyceride contents in the N group was higher than that of the HF group, and those of the HEA, HEB and HEC groups were lower than that of the HF group. This study suggested that the ethanol extracts from red pepper seeds have powerful health benefits by the UDP-glucuronyl transferase activity and lipid metabolism.

• Proceedings of the Korea Water Resources Association Conference
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• 2017.05a
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• pp.348-348
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• 2017

최근 기후변화로 인해 국지성 호우 등 이상기후의 발생이 증가하고 있으며, 이에 따른 홍수피해 역시 증가하고 있다. 우리나라에서도 연 강수량의 30% 이상의 강우가 하루에 집중되어 내리는 등 집중호우의 발생이 빈번이 일어나고 있으며, 이로 인한 홍수피해에서 자유롭지 못한 실정이다. 실무에서 홍수에 의한 하천 수위는 대부분 HEC-RAS를 이용해 산정하고 있다. 하천 범람에 의한 제내지 침수해석의 경우 일부 연구에서 HEC-RAS를 이용하여 1차원적으로 수행된 바 있으나, 많은 연구자들은 HEC-RAS와 2차원 수치해석 모형을 연계하여 수행하고 있다. 최근 미육군공병단에서는 기존의 1차원 수위모의와 연계하여 2차원 침수모의가 가능한 HEC-RAS 5.0 버전을 개발하여 공개하였다. 본 연구에서는 HEC-RAS 최신버전을 이용하여 청미천 유역의 2차원 침수 모의를 수행하고, 그 적용성을 평가하고자 한다. 대상지역은 침수흔적도를 이용하여 청미천 유역에 위치한 침수발생지구를 선정하였다. 하천단면자료는 청미천 하천기본계획의 측량자료를 사용하였으며, 강우자료는 인근 기상관측소의 관측자료를 수집하였다. HEC-HMS를 이용하여 강우에 의한 유출량을 산정하였으며, 산정된 유출량을 HEC-RAS에 입력하여 수위를 계산하고 2차원 모의기능을 이용하여 침수해석을 수행하였다. HEC-RAS를 이용한 2차원 침수 모의 방법은 향후 하천범람에 의한 침수해석에 널리 활용될 것으로 예상되며, 본 연구의 결과는 이를 위한 적용성 분석의 기초자료로 활용될 수 있을 것으로 기대된다.

• Journal of The Korean Society of Agricultural Engineers
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• v.46 no.5
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• pp.107-116
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• 2004

A GIS-based paddy inundation simulation system which is capable of simulating temporal and spatial inundation processes was established and applied in this paper. The system is composed of HEC-GeoHMS, and HEC-GeoRAS modules which interface the GIS and flood runoff models, and HEC-HMS, and HEC-RAS models which estimate the flood runoff. It was used to simulate storm runoff and inundation for a small rural watershed, the Baran HP#7, which is 10.69 $km^2$ in size. The simulated peak runoff, time to peak, and total direct runoff for eight storms were compared with the observed data. The results showed that the coefficient of determination ($R^2$) for the observed peak runoff was 0.99 and an error, RMSE, 11.862 $m^3$/s for calibration stages. In the model verification, $R^2$ was 0.99 and RMSE 1.296 $m^3$/s. Paddy inundation for each paddy growing stages in study watershed were estimated using verified inundation simulation system when probability rainfall was applied.

• Journal of Korea Water Resources Association
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• v.30 no.6
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• pp.721-729
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• 1997

Total scour depth at a bridge is comprised of three components: long-term changes, contraction scour and local scour. Therefore, the analysis of long-term bed elevation changes is very important in the estimation of total scour depth at bridge sites. In this research, long-term bed elevation changes at the Namhan River Bridge are analysed using CHARIMA and HEC-6 models. The results show that, for 5-year steady normal stream flow, the bed elevation is aggreded by 45cm for CHARIMA model but degraded by 5cm for HEC-6 model. For 5-year unsteady flow, the bed elevation is changed greatly and it has a great influence on the estimation of total scour depth. Therefore, to make a proper estimation of total scour depth, not only contraction scour and local scour, but also long-term bed elevation changes should be estimated precisely.

• Journal of the Korean Society of Hazard Mitigation
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• v.8 no.5
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• pp.129-135
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• 2008

USWMM was developed as a drainage analysis system for estuarine urban areas by adding sluice gates on existing EPA SWMM5 through this study. For the purpose of reviewing, Ansungchon river was modeled with USWMM and calibration and verification were attempted at three observation stations. In comparison, another approach using HEC-HMS and HEC-RAS was applied to the area under the same condition. It turned out that USWMM resulting values were closer to the observed values than those of the HEC-HMS and HEC-RAS approach. USWMM's flow simulation through sluices were more realistic to sluice operation fields by adding incomplete submerged orifice flow equation and maintenance water level. In sum, USWMM can be seen as a general purpose tool for estuarine urban drainage analysis system.

• Journal of Korea Water Resources Association
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• v.45 no.5
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• pp.505-516
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• 2012

The study applies a hydrologic simulation model, HEC-1 developed by Hydrologic Engineering Center to Daecheong dam watershed for modeling hourly inflows of Daecheong dam. Although the HEC-1 model provides an automatic optimization technique for some of the parameters, the built-in optimization model is not sufficient in estimating reliable parameters. In particular, the optimization model often fails to estimate the parameters when a large number of parameters exist. In this regard, a main objective of this study is to develop Bayesian Markov Chain Monte Carlo simulation based HEC-1 model (BHEC-1). The Clark IUH method for transformation of precipitation excess to runoff and the soil conservation service runoff curve method for abstractions were used in Bayesian Monte Carlo simulation. Simulations of runoff at the Daecheong station in the HEC-1 model under Bayesian optimization scheme allow the posterior probability distributions of the hydrograph thus providing uncertainties in rainfall-runoff process. The proposed model showed a powerful performance in terms of estimating model parameters and deriving full uncertainties so that the model can be applied to various hydrologic problems such as frequency curve derivation, dam risk analysis and climate change study.