• Water for future
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• v.9 no.2
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• pp.101-114
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• 1976

This paper presents a hydrologic method of probabilistic design flood calculation for ungauged small river basins. It is based on the study and analysis of the physiographic characteristics of the river basin for which stream flow records may not be available. Rainfall data is used at nearby station which has the rainfall intensity-duration-frequency relations. Musim cheon, second tributary of the Guem river, is selected for the sample study. Design floods for the stream reaches are computed by the Rational formula, the runoff coefficients being determined with the physiographic data such as soil type, land use and vepetal covers. Derived unit hydrograph at conneted main river basin is used to compute the peak flood discharge. Kajiyama formula and modified Kajiyama formula are used to calculated the most probable maximum flood discharge. The result of this study shows that synthesized unit hydrograph method is more accurate and applicable way to com pute design flood for ungauged small river basins.

• Journal of the Korean Society of Hazard Mitigation
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• v.7 no.1 s.24
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• pp.47-56
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• 2007

The parameters are determined analyzing the hydraulic and hydrological characteristics of design floods, watershed, channel length, and river bed slope. The models are calibrated while the input hydrologic data are the field data of middle size areas in Guem river basin in Korea. The basic equations of design width are suggested by the multiple regression analysis and the results show excelled in comparisons as well as calibrations with the existing empirical formulas and the design criteria, respectively. The basic equations of design width in validation process is determined the regression functions with the design floods, watershed, channel length, river bed slope as the four parameters using other database in the same scales watershed. As a results, this study will be used for apply to determine of design width and river alignmentof the watershed in hydraulic fields.

• Research in Community and Public Health Nursing
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• v.27 no.4
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• pp.346-357
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• 2016

Purpose: This study attempted to investigate the prevalence and related factors of Clonorchiasis among five major riverside residents in South Korea. Methods: This study is descriptive research, nationwide survey, and the subjects are 23,492 residents selected by convenience sampling. Data collection was conducted between March 1 and June 30, 2011, and stool collection and questionnaire survey were conducted by affiliated public health centers in 38 cities and Gun's. Results: The prevalence rates of Clonorchiasis in the five major riversides were as follows: the Guem River 15.2%; the Nakdong River 11.9%; the Seomjin River 10.9%; the Han River 5.7%; and the Yeongsan River 3.9%. The prevalence rates were shown to be significantly high among people who had highly frequent experiences of eating and cooking freshwater raw fish, were diagnosed with liver and/or biliary tract diseases, and drank less than once a month. Conclusion: These results suggest that it is necessary to improve awareness of Clonorchiasis and provide intensive public health education for the riverside residents. And the target groups should be set up by reflecting the characteristics of at-risk groups, and it is necessary to prepare customized strategies for prevention and management of Clonorchiasis.

• Journal of Korean Society on Water Environment
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• v.30 no.2
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• pp.148-158
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• 2014

In order to assess the effect of TMDLs management and improve that in the future, it is necessary to analyze long-term changes in water quality during management period. Therefore, long term trend analysis of BOD was performed on thirty monitoring stations in Geum River TMDL unit watersheds. Nonparametric trend analysis method was used for analysis as the water quality data are generally not in normal distribution. The monthly median values of BOD during 2004~2010 were analyzed by Seasonal Mann-Kendall test and LOWESS(LOcally WEighted Scatter plot Smoother). And the effect of Total Maximum Daily Loads(TMDLs) management on water quality changes at each unit watershed was analyzed with the result of trend analysis. The Seasonal Mann-Kendall test results showed that BOD concentrations had the downward trend at 10 unit watersheds, upward trend at 4 unit watersheds and no significant trend at 16 unit watersheds. And the LOWESS analysis showed that BOD concentration began to decrease after mid-2009 at almost all of unit watersheds having no trend in implementation plan watershed. It was estimated that TMDLs improved water quality in Geum River water system and the improvement of water quality was made mainly in implementation plan unit watershed and tributaries.

• Journal of the Korean Society of Hazard Mitigation
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• v.3 no.3 s.10
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• pp.165-171
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• 2003

An abnormal storm by the typhoon of RUSA in 2002th year was broken out with tremendous flood demages and inundations on the basin of Chogangcheon located in the upper middle part of Guem river's upstream. This flood could not be engaged because it was so big that the stage engaging Songcheon station stuck to Songcheon bridge was destroyed by submerging. In this study the quantity of the flood was calculated by use of Manning's equation and suitable roughness coefficient was suggested.

• Journal of Korean Society on Water Environment
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• v.28 no.6
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• pp.786-795
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• 2012

Water quality management should be focused on the pollution concentrated area so that the improvement of water quality can be achieved effectively for the management of Total Maximum Daily Loads (TMDLs). It is necessary to consider discharge characteristics in the TMDL plan. This study analysed discharge characteristics such as pollution generation and discharge load density, and reduction potential by each unit watershed, and categorized the unit watershed into four groups according to its discharge load characteristics. This analysis can be used as helpful information for the prioritization of pollution reduction area and selection of pollution reduction measures in the development of TMDL plans.

• Proceedings of the Korea Water Resources Association Conference
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• 2018.05a
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• pp.47-47
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• 2018

최근 이상기후로 인한 강우 패턴의 변화, 홍수와 가뭄 등으로 인하여 하천 환경은 급격한 변화를 경험하고 있다. 급격한 외부 조건에 따른 하천 환경의 변화를 평가하고 예측하기 위하여, 현재까지의 하천의 유황 조건 변화와 그에 따른 하천 지형과 생물상 변화를 토대로 대상하천의 기존의 변화 프로세스를 이해하는 것은 필수적이다. 본 연구에서는 향후 금강유역의 하천관리 및 복원사업에 이용하기 위하여 1960년대부터 현재까지의 금강의 하천 지형 변화를 파악하고 변화 양상을 분석하고자 한다. 본 연구에서는 금강 하구둑의 건설 전 후, 용담댐과 대청댐의 건설 전 후, 4대강 보(세종보, 공주보, 백제보)건설 전 후의 대상 하천의 평면적 지형 변화를 년도 별 항공사진을 통하여 지형 변수 (굴곡도, 하폭 등) 변화를 분석하고, 4대강 보 건설 구역에 대하여 건설 전 후의 지형 변화 모델링 및 생물 서식처 평가 모의를 실시한다.

• Journal of Korean Society on Water Environment
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• v.36 no.6
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• pp.521-534
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• 2020

In this study, the variation of water quality was analyzed for six sites in major tributaries of the Nakdong River Basin. Standard-FDC (Flow Duration Curve) was developed using PM (Percentile Method), one of the statistical FDC estimation methods. The LDC (Load Duration Curve) was obtained using the developed FDC. The current method and the LDC evaluation method were compared and analyzed to evaluate the achievement of TWQ (Target Water Quality). Regarding the monthly flow rate variation, the five sites showed the distribution of the lowest flow rate between May and June, indicating a high probability of dry weathering of the streams. The variation of water quality confirmed the vulnerable timing of flow rate in each site, and it is therefore deemed necessary to plan to reduce T-P and TOC. A comparison and evaluation of TWQ showed that there was a difference between the TWQ values achieved by the two techniques. In addition, the margin ratio to the 50% excess ratio can be found in the LDC evaluation. The results of the LDC evaluation by section and by month showed whether or not the water quality was exceeded by flow conditions, along with the vulnerable sections and timing. Accordingly, it is judged that this method can be used for water quality management in TMDLs (Total Maximum Daily Loads).

• Proceedings of the Korea Water Resources Association Conference
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• 2021.06a
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• pp.312-312
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• 2021

최근 이상기후의 발생이 증가함에 따라 집중호우, 가뭄, 태풍 등 자연재해의 발생빈도가 증가하고 있다. 이러한 자연재해 중 태풍 등의 극한 홍수 사상의 발생으로 인하여 재산 및 인명피해가 급증하고 있다. 이러한 태풍과 같은 자연재해로부터 안전한 하천 관리를 수행하기 위해서는 신뢰할 수 있는 수문 관측 자료를 바탕으로 유출량 산정이 필수적이다. 본 연구에서는 금강 유역에서 발생한 주요 태풍 사상을 바탕으로 지역화 연구를 수행하였다. 강우-유출 해석을 위하여 개념적 강우-유출모형인 PDM 모형을 활용하였으며, 유역면적, 수계밀도 등 7개의 유역 특성인자를 활용하여 Monte-Carlo 방법을 이용하여 모형의 최적화 매개변수를 도출하였다. 또한, 최적화 매개변수를 바탕으로 PDM 모형의 매개변수별 지역화 모형을 구축하였다. 금강 유역을 대상으로 지역화 모형을 적용한 결과 NSE 목적함수 값이 0.70 이상인 우수한 결과를 확인하여 개발된 지역화 모형이 태풍 사상의 유출특성과 금강 유역의 유역특성을 우수하게 반영하고 있음을 확인하였다. 본 연구의 결과를 바탕으로 향후 미계측 유역에서도 적용할 수 있는 지역화 모형을 개발하고자 한다.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.14 no.5
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• pp.1191-1197
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• 1994

The purpose of this study is to examine morphometric characteristics in a channel bend reach. The new shape factor is suggested that channel deformation rate of cross section (${\Delta}A_s$) showed the variation of concentrated location of force due to the current and the variation of erosional section in alluvial channel. In the downstream direction the meaning of decreasing "${\Delta}A_s$" is the stability of channel bed. This study was analyzed morphological characteristics of cross section-width of channel ($W_s$), width to the thalweg ($W_{th}$), maximum depth ($D_{th}$)-on the Guem River, and typical cross sections in channel bend were proposed. The channel migration rate (M) for the study river was represented that the zones of curvature ratio (R/W) with 2~4 were larger 12% than other zones.