• Proceedings of the Korea Water Resources Association Conference
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• 2005.05b
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• pp.1269-1273
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• 2005

자연 친화적 하천관리는 현 치수위주의 하천정비 관행으로 인한 하천의 환경 기능의 훼손을 막고, 제도적으로 자연 친화적으로 하천 사업을 추진하기 위해서 수변조사, 계획, 설계, 시공, 모니터링, 그리고 유지관리 등 일련의 체계적인 절차에 따라 하천 사업을 시행하는 것이다. 특히 이러한 표준 절차 가운데 수변조사는 하천의 특성을 결정짓는 여러 가지 자연적, 인공적 형성과정들과 그 과정들을 지배하는 생태학적 원리들을 파악하여 하천사업의 정비주제와 방향을 설정하는데 도움을 준다. 모니터링은 계획과 설계, 시공을 통해 실시된 하천사업의 효과를 평가하고, 공법적용에 따른 하천의 변화과정을 파악하여 유지관리 및 적응관리를 위한 근거를 제시하는 과정이다. 수변조사 및 모니터링 매뉴얼은 건설교통부가 수행한 '자연친화적 하천정비기법 개발' 의 연구성과로서, 경기도의 탄천, 충청북도의 달천 그리고 경기도 오산천을 대상으로 각 관련분야의 전문가가 참여하여 직접 적용$\cdot$검증한 결과를 바탕으로 제작한 것이다. 이는 하천의 관리 및 하천관련 사업을 자연 친화적으로 수행하기 위하여 필요한 '수변조사'와 '모니터링'에 대한 일반적인 절차와 방법을 체계화 한 것이다. 특히 수변조사 매뉴얼의 경우는 $\ulcorner$하천설계기준$\lrcorner$의 '제12장 하천환경조사'를 보완하는 관계에 있다. 하천설계기준에서 제시한 하천환경조사는 본 수변조사 매뉴얼상과 동일한 절차와 양식을 따르고 있다. 하천설계기준에서 자세하게 기술하지 못한 조사방법, 정리, 분석, 평가에 대한 내용을 구체적으로 적용하여 이를 보완하고 있다.은 안양천 웹페이지(http://anyang.river.or.kr)에서 구현되고 있으며, 앞서 설명한 바와 같이 1단계 프론티어 사업으로 설치된 4개의 하천수위, 2개의 지하수위 관측시설과 함께, 2단계에 (주)웹솔루스에서 자체적으로 설치 운영하고 있는 2개소의 하수관거 모니터링 관측시설, 그리고 안양시에서 운영하고 있는 5개소의 강우관측소와 7개소의 수위관측소를 모두 통합하여 실시간 자료를 제공하고 있다. 수위자료는 10분단위의 텍스트정보와 그래프형태로 지원되며, 검색기간 설정을 통해 원하는 기간내의 자료를 선별, 검색할 수 있다.. 또한 이와 같은 기초적인 정보를 바탕으로 하류하천의 탁수 피해를 최소화할 수 있는 선택취수탑의 운영방안을 수립할 수 있다 본 연구에서는 이를 위해 선택취수탑 주위의 성층흐름을 기존의 실험자료와 수치해석을 통하여 분석하였고, 온도성층구조나 취수구의 위치변화에 따른 방류수 수질특성을 조사하였다.쇄파대(artifical reef)와 같은 완충지대를 갖는 호안을 축조함으로써 월파량을 감소시키는 대안으로 제시하고자 한다. 본 연구 수행을 통해 태풍 내습시 발생 가능한 자연재해에 대한 사전 방지를 목적으로 태풍피해의 원인을 제시하고 이를 해결하여 현재의 방재대책이 항구적인 방재대책으로 전환될 수 있는 방안 마련의 기초 자료로 활용되기를 기대한다., L-arabinose, 및 D-galactose; 제3차(第三次) 가수분해물(加水分解物)(C)에서 L-rhamnose, D-xylose, L-arabinose 및 D-galactose, 비가수분해물(非加水分解物)(C')에서 D-xylose와 D-galactose를 검출(檢出)하였다. (4) 구성당(構

• Journal of Korea Water Resources Association
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• v.50 no.4
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• pp.241-252
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• 2017

This study aims to evaluate applicability of both online and offline parameter calibration techniques on rainfall-runoff modeling using a conceptual lumped hydrologic model. To achieve the goal, the storage function model was selected and then two different automatic calibration techniques: SCE-UA (offline method) and particle filter (online method) were applied to calibrate the optimal parameter sets for 9 rainfall events in the Cheoncheon catchment, upper area of the Yongdam multi-purpose dam. In order to assess reproducibility of hydrographs from the parameter sets of both techniques, the observed discharge of each event was divided into low flow (below average flow) and high flow (over average flow). The results show that the particle filter method, updating the parameters in real-time, provides more stable reproducibility than the SCE-UA method regardless of low and high flow. The optimal parameters estimated by SCE-UA are very sensitive to the selected objective functions used in this study: RMSE and HMLE. In particular, the parameter sets from RMSE and HMLE demonstrate superior goodness-of-fit values for high flow and low flow periods, respectively.

• Korean Journal of Environmental Biology
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• v.23 no.3 s.59
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• pp.304-314
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• 2005

The occurrence of cyanobacterial bloom in Korean lakes of the summer is generalized. The characteristic of cyanobacterial community was explored. And the developmental stage of cyanobacterial bloom was divided into three phases, 'preparatory phase', 'bloom phase' and 'extinction phase' Cyanobacterial bloom started during the end of June at site 1, transition Bone of Lake Daecheong. The period of water bloom in normal year was about 60~70 days at site 4, lacustrine Bone, but it was unusually 11 days from July 19 in 1999. M. aerugilnosa first occurred in June, had a peak of standing crop curve from the end of August to the beginning of September in 1998 and 2002 and the end of July in 1999 and 2001. The standing crop of M. aeruginosa occupied $68.1\%$ of phytoplankton, $74.2\%$ of cyanobacteria and $88.8\%$ of genus Microcystis, Anabaena spp. first occurred in April, was above 10,000 cells $mL^{-1}$ from the end of August to about the middle of September in 1998. The effect of rainfalls on cyanobacterial bloom was different according to the phases. The rainfalls of preparatory phase assist the growth of cyanobacteria, but accelerate the decrease of cyanobacteria in extinction phase. In bloom phase, the heavy rainfalls reduce the development of the bloom, while the slight ones display only a little effects.

• Fire Science and Engineering
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• v.24 no.2
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• pp.67-75
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• 2010

The fuel moisture changes accompanying with the elapsed days after a rainfall is very important to predict the risk of forest fire and make a good use of forest fire guard. So, to investigate the conditions for the risk of forest fire, it was studied the risk of forest fire for fallen leaves level, rotten level, and soil level after more-than-5 mm-rainfall according to the different forest density of pine forests which were located in Yeong-dong region in the Spring of 2007. The result of the study showed that the around 17% of fuel moisture which was the risky level for forest fire was reached after three days of a rainfall in the coarse dense forest region and after five days in the medium or highly dense forest region. However, for the rotten level represents more than 30% of fuel moisture even after six days after the rainfall, and the lower and upper level of the soil represented a slight or almost no changes. Based on the result, the prediction model ($R^2$=0.56~0.87) for the change of fuel moisture was developed, and it was examined by applying to actual meteorological measurements in the same period of 2008. It showed a meaningful result of 1% level of distinction.

• Fire Science and Engineering
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• v.24 no.4
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• pp.18-26
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• 2010

The change of fuel moisture according to the passed days after a raindrop is very important to forecast risk of forest fire and to make a good use of forest fire watchmen. For that reason, in the Spring of 2007, we researched pine forest that were widespread growing in Yeongdong region to find out the condition of forest fire risk. We developed the forecast model of fuel moisture change on dead tree branches which were dropped on the ground and less than 0.6 cm, 0.6~3.0 cm, 3.0~6.0 cm, and more than 6.0 cm in diameter after more than 5.0 mm in precipitation. The result showed that the less diameter of ground fuel and small stand of pines the faster diminishing of fuel moisture, and the days of reaching to a forest fire danger fuel moisture level were represented by two (2) days for less than 0.6 cm diameter of small stand of pine and three (3) days for 0.6~3.0 cm diameter one, respectively. By those results, we developed the forecast model($R^2=0.76{\sim}0.92$) of fuel moisture change on different diameter of small stand of pine, and found that the model had statistical significant of 1% level after we applied it to the data of 2008 after the same period of raindrop by actual meteorological measurement.

• Journal of Korea Water Resources Association
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• v.37 no.9
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• pp.707-718
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• 2004

This study is to analyze the Probable Maximum Flood(PMF) as a part of counterplan for the disaster prevention of hydraulic structures such as dams, according to recent unfavorable weather conditions. During the period of typhoon RUSA in August 2002, the rainfall recorded in Gang-loeng Province was 880mm a day and exceeded the scale of PMP made in 2001. Accordingly, the reconsideration of hydrologic criteria for dam design was inevitable. In the design of dams for flood controls, the design flood must be determined by introducing the concept of maximum values. When the duration of design rainfall is determined, it needs to use the critical duration which causes the maximum flood by the maximum runoff. In this study, we Investigate the variation of critical duration with hydrologic parameters used in three different synthetic unit hydrographs(Clark, Nakayasu and SCS methods). As a result, the total runoff calculated from 24-hour duration is larger than that calculated from the critical duration. We calculate also the hydrographs with three different time distribution models(Huff's 4-quartile, IDF curve and Mononobe) and compare those with measured hydrograph data. From this comparison, we propose that the Huff's 4-quartile model must be used to obtain the desirable data in the hydrologic design of dams.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.6B
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• pp.709-721
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• 2008

This paper is to test the applicability of ModKIMSTORM (Modified KIneMatic Wave STOrm Runoff Model) by applying it to Namgangdam watershed of $2,293km^2$. Model inputs (DEM, land use, soil related information) were prepared in 500 m spatial resolution. Using five typhoon events (Saomi in 2000, Rusa in 2002, Maemi in 2003, Megi in 2004 and Ewiniar in 2006) and two storm events (May of 2003 and July of 2004), the model was calibrated and verified by comparing the simulated streamflow with the observed one at the outlet of the watershed. The Pearson's coefficient of determination $R^2$, Nash and Sutcliffe model efficiency E, the deviation of runoff volumes $D_v$, relative error of the peak runoff rate $EQ_p$, and absolute error of the time to peak runoff $ET_p$ showed the average value of 0.984, 0.981, 3.63%, 0.003, and 0.48 hr for 4 storms calibration and 0.937, 0.895, 8.08%, 0.138, and 0.73 hr for 3 storms verification respectively. Among the model parameters, the stream Manning's roughness coefficient was the most sensitive for peak runoff and the initial soil moisture content was highly sensitive for runoff volume fitting. We could look into the behavior of hyrologic components from the spatial results during the storm periods and get some clue for the watershed management by storms.

• Korean Journal of Agricultural and Forest Meteorology
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• v.15 no.3
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• pp.161-170
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• 2013

Spatio-temporal distribution of soil moisture was studied to improve understanding of hydrological processes at hillslope scale. Using field measurements for three designated periods during the spring, summer and autumn seasons in 2010 obtained from Beomryunsa hillslope located at the Sulmachun watershed, correlation analysis was performed between soil moisture measurements and 18 different terrain attributes (e.g., curvatures and topographic index). The results of correlation analysis demonstrated distinct seasonal variation features of soil moisture in different depths with different terrain attributes and rainfall amount. The relationship between predicted flow lines and distribution of the soil moisture provided appropriate model structures and terrain indices.

• Journal of Korea Water Resources Association
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• v.45 no.3
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• pp.253-262
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• 2012

The objectives of this study are to suggest the method for estimation of sub-daily extreme rainfall under climate change using scale properties and to assess the application in the 6 major weather stations including Seoul site. First, the proposed method was assessed by past observations. As the results, absolute relative errors of probability rainfall quantiles estimated by frequency analysis and scale property method show approximately 10% in the all durations. And as the result of application climate scenario, absolute relative errors of rainfall quantiles between two method show approximately 20%. From the results, the scale property method on this study will be derive as the reliable results.

• Proceedings of the Korea Water Resources Association Conference
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• 2006.05a
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• pp.214-220
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• 2006

본 연구의 목적은 지역별 농업가뭄의 평가를 위하여 농업가뭄지표의 적용성을 분석하는 것이다. 가뭄발생 상황에 분석은 SPI, PDSI, SWSI, CMI, Decile 및 Percent of Normal에 대하여 농업가뭄에 대한 적용성을 검토하였다. 기존 가뭄지수에 대한 가뭄발생시기 및 심도에 대한 분석을 통하여 농업가뭄을 잘 나타낼 수 있는 농업용 저수지 저수율과 3개월 지체된 표준강수지수, 평년강우비율, 무강우일수 등 4가지를 농업가뭄지표로 선정하였으며, 이들 지수를 통하여 가뭄평가에 적용하였다. 농업가뭄 평가를 위하여 평시대비단계, 가뭄우려단계, 가뭄확산단계의 3단계로 구성된 기존의 가뭄단계를 가뭄진행상황의 판단을 위해 6단계로 세분하여 이에 대한 기준을 정립하였다. 농업용 저수지의 저수율에 따른 농업가뭄의 판단은 영농시기에 대한 농업용수의 공급에는 적당하지만, 겨울에서 봄으로 이어지는 영농준비시기 및 논에서의 영농이 끝난 후의 가을철 이후의 가뭄에 대해서는 대표적인 기준으로서는 미흡한 것으로 나타났다. 농업용 저수지의 저수율에 따른 농업가뭄의 표현은 저수율의 지연효과, 저수율과 가뭄심도의 일반화된 상관성을 수립하기 어려운 단점이 있으므로, 영농상황에 따른 시기별 저수율의 고려할 수 있도록 구성하고, 표준강수지수, 평년강우비율 및 무강우일수 등의 지수를 이용하여 보완하도록 하였다. 이를 통해 제시된 농업가뭄지표 및 가뭄단계에 의한 농업가뭄 평가 결과 농업가뭄 발생시기, 지속기간 및 심도에 대한 적용성이 우수한 것으로 분석되었다. 농업가뭄지표 및 농업가뭄단계는 농업가뭄 평가 및 웹기반 정보제공시스템의 구축을 통하여 농업가뭄 분석 및 판단에 이용하고 있다. 농업가뭄의 분석 및 평가를 위한 농업가뭄 평가시스템은 가뭄분석을 위한 자료의 수집 및 분석, 농업가뭄심도의 분류, 지역별 농업가뭄 상황의 도식화 등을 수행하도록 구성되어 있다. 농업가뭄 평가시스템을 통해 구축된 시기별, 지역별 분석결과는 DB를 통하여 관리되며, 홈페이지를 통하여 실시간 분석결과를 제공할 수 있도록 웹기반 정보제공시스템을 구축하였다. 이상과 같은 농업가뭄 평가 및 웹기반 정보제공시스템은 현재 한국농촌공사 농어촌연구원에서 시범운영중에 있으며 농업가뭄의 평가 및 대책수립을 위한 지원수단으로 효율적으로 활용될 수 있을 것으로 판단되었다.