• Proceedings of the Korea Water Resources Association Conference
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• 2022.05a
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• pp.192-192
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• 2022

하천유량은 기저유량과 직접유량으로 구성되어 있으며 기저유량은 갈수기 하천유량의 대부분을 차지하므로 직접유출과 기저유출의 분리는 중요하다. 또한, T-N, T-P는 기저유출에 영향을 많이 받는 수질 항목으로 기저유출과 직접유출에 의한 오염부하량을 정확히 분석해야한다. 따라서, 기저유출의 오염부하량 산정을 위해 기존의 WAPLE 2의 단점을 개선한 WAPLE 3가 개발되었으며, WAPLE 3는 유량 곡선의 하강부 변곡점에 붙는 특성을 가지고 있는 Baseflow filter program(BFlow) pass 1값을 사용하여 기저유량을 분리해 기저유출 오염부하량을 산정한다. WAPLE 3는 하천유량 중 기저유출을 어느 정도 분리하는지 결정하는 filter parameter 값을 Nathan과 McMahon가 제시한 최적값인 0.925를 사용하였다. 그러나 지형과 강우량 등에 따라 하천 유량에서의 기저유출 비율은 달라지기 때문에 이러한 한계점을 극복하기 위해 WAPLE 4를 개발하였다. WAPLE 4는 filter parameter 값을 사용자가 변경할 수 있게 개발하여 강우에 의한 유량변동 특정이 고려된 기저유량 및 오염부하를 산정하여 결과에 대한 정확도를 높였다. 또한, WAPLE 4는 강우시 오염부하량 산정에 탁월한 Numeric Integration(NI) 방법을 사용하여 직접유량, 기저유량의 오염부하량 및 유량가중평균농도(FWMC) 산정이 가능하도록 하였다. 본 연구의 결과는 오염총량제 및 기저유량 관리를 통한 유량 관련 정책 수립 시 기초자료로 활용될 수 있을 것으로 판단된다.

• The Korean Journal of Ecology
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• v.25 no.3 s.107
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• pp.189-195
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• 2002

In order to elucidate the budget and cycling of Nitrogen and Sulfur, essential elements and principal constituents of acid rain, their input through precipitation, and their output by streamflow were quantified in coniferous and deciduous forested watersheds, using combination of nutrient concentration and hydrological analysis, in Kwangnung Experimental Forest from July 1991 to December 1993. Amount of annual mean precipitation was $12,916\;ton{\cdot}ha^{-1}{\cdot}yr^{-1}$, annual mean runoff $5,094\;ton{\cdot}ha^{-1}{\cdot}yr^{-1}$(39%), $7,467\;ton{\cdot}ha^{-1}{\cdot}yr^{-1}$(59%) in coniferous and deciduous forest watersheds, respectively. Amounts of annual input of $N({NO_3}^-+{NH_4}^+)$ and ${SO_4}^{2-}$ through preciptation were 12.5, $81.72\;kg{\cdot}ha^{-1}{\cdot}yr^{-1}$, repectively. Annual output via runoff of $N({NO_3}^-+{NH_4}^+)$ and ${SO_4}^{2-}$ were 0.06, $39.23\;ton{\cdot}ha^{-1}{\cdot}yr^{-1}$ in the coniferous forest watershed ecosystem, and 0.15, $55.46\;ton{\cdot}ha^{-1}{\cdot}yr^{-1}$ in the deciduous one, respectively. On the basis of annual nutrient input and output, the annual budget of $N({NO_3}^-+{NH_4}^+)$ and ${SO_4}^{2-}$ were +12.46, $+42.49\;ton{\cdot}ha^{-1}{\cdot}yr^{-1}$ in the coniferous forest watershed, and +11.35, $+26.26\;ton{\cdot}ha^{-1}{\cdot}yr^{-1}$ in the deciduous one. Thus $N({NO_3}^-+{NH_4}^+)$ and ${SO_4}^{2-}$ were accumulated in both forested watershed ecosystems.

• Journal of the Korean Geographical Society
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• v.36 no.2
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• pp.111-125
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• 2001

An estuary is semi-inclosed inlets, located between terrestrial and marine environment. Since many estuaries along south-western coasts of Korean peninsula were affected by human settlements and activities, significant changes in sedimentation environments have been observed. The research area is divided into three distinct morpho-stratigraphic units: fluvial dominated area(Area1), mixed area(Area 2), tide-dominated area(Area3). The landform of this area has been changed by reclamation and river channel change. Temporal variations affected by dam construction, periodic freshet was iterrupted. Sediments began to continuously accmulate on estuary banks by tide. Meanwhile, because of the continuous but reduced discharge of fresh water, the salinity of estuarine sediments was declined. That processes made vegetated area( Phregmites lonivalvis and Suaeda japonica) to be expanded. It indicates that the magnitude and frequency of geomorphic processes has been significantly changed.

• Journal of Korea Water Resources Association
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• v.47 no.6
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• pp.501-511
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• 2014

The effects of initial conditions and input values of the rainfall-runoff model were studied in the applications of a lumped concept model for flood event data extension. For the initial conditions of the rainfall-runoff model, baseflow effects and spatial distributions of saturation points ($R_{sa}$) for the storage function methods (SFM) were analyzed. In addition, researches on the effects of rainfall data conditions as input values for the rainfall-runoff model were performed. The Chungju Dam watershed was selected and divided into 3 catchments including smaller size of 22 sub-catchments. The observed discharge and inflow amounts at Yeongwol 1, Chungju Dam, and Yeongwol 2 water level stations were individually operated as criteria for flood data extension in 30 flood events from 1993 to 2009. Direct and base flow were distinguished from a stream flow. In order to test capability of flood data extension, obtained base flow was applied to the rainfall-runoff model for three water level stations. When base flow was adopted in the model, the Nash-Sutcliffe Efficiency(NSE) was increased. The numbers of over satisfaction for model performance (>0.5) were increased over 10%. Saturation points ($R_{sa}$) which strongly influence the runoff amount when rainfall starts were optimized based on the runoff amount at three water level stations. The sizes of saturation points for three locations were similar which means saturation point size is not depending on the runoff amount. The effects of rainfall information for flood runoff were tested at 2002ev1 and 2008ev1. When increased the amount of rainfall information, the runoff simulations were closer to the simulations with full of rainfall information. However, the size of improvement was not substantial on rainfall-runoff simulations in terms of the size of total amount of rainfall.

• Journal of Korean Society of Forest Science
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• v.89 no.3
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• pp.342-355
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• 2000

This study was carried out to reveal the influence of discharge change on matters and stream water quality between pH, EC and dissolved matters obtained by observation of long-term and short-term on stream water quality and separated runoff components from stream water by using HYCYMODEL. From January in 1998 to September in 1999, it was estimated by relationships of character of water quality and discharge for the experimental watershed in Mt. Palgong. The results were summarized as follows : 1. Annual average pH values of stream water in 1998 and in 1999 were 6.48(6.22~6.89) and 6.52(5.75~7.18), respectively. The observed annual average pH values were maintaining identical values in general, but pH values decreased continuously during the four months after thinning in the experimental watershed. So thinning is suspected of the major cause for the decrease. 2. Annual average EC values of stream water in 1998 and in 1999 were $26.69(17.95{\sim}33.5){\mu}S/cm$ and $25.19(17.5{\sim}33.8){\mu}S/cm$, respectively. The observed annual average EC values were maintaining identical values in general. 3. As a result of the comparison of average dissolved ions of rainfall and stream water, $Na^+$, $Mg^{2+}$, $Ca^{2+}$, $Cl^-$, $NO_3{^-}$, and $SO_4{^{2-}}$ showed minus values between incomings and outgoings. $Na^+$ and $NO_3{^-}$ among the dissolved ions of stream water showed the highest concentration out of cations and anions respectively. 4. By the change of pH value in stream water due to rainfall events, pH value decreased with increasing runoff as pH value increased before and after peak flow. 5. By the change of EC value in stream water due to rainfall events, EC value decreased with increasing runoff of first rainfall as EC value changed with runoff before and after peak flow. 6. As the runoff increased, the concentration of $Na^+$, $Ca^{2+}$, $K^+$, total cation, $Cl^-$, and $SO_4{^{2-}}$ in stream water lowered. On the other hand, the runoff decreased, their concentration in stream water tended to get high. But in terms of $NO_3{^-}$ and total anion, they turned out vice versa. $Mg^{2+}$ produced no reaction. 7. The base flow among runoff components separated by using HYCYMODEL influenced greatly on pH, EC, concentration of cation and anion.

• Journal of the Korean GEO-environmental Society
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• v.2 no.3
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• pp.37-45
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• 2001

The characteristics of drinking groundwater quality was analyzed by investigating observed data during 1995-1997 in Daejeon city. As the analysis of observed data, the 30.1% of them were over the drinking water quality standards in Daejeon city and the unfit ratios of each region were 36.4% at Dong-Gu, 32.3% Daedeog-Gu, 31.2% Jung-Gu, 30.0% Seo-Gu and 25.2% at Yusoung-Gu. It was found that the items over the drinking water quality standards were 24 items and all of the mean concentration of water quality items were under the drinking water quality standard except Fe and Mn in 1997. The mean concentration of Fe was $1.31mg/{\ell}$ over the water quality at Daedeog-Gu and that of Mn was $0.53mg/{\ell}$ at Jung-Gu. The concentrations of $NH_3$-N, Mn, Fe, Al and F were increased rapidly in 1997, so that the cause of increasing also must be examined closely. It was found that the rainfall and unfit ratio(unfit frequency/test frequency) of E-coli and bacteria had the hydrologic persistance. The coefficient of correlation between them was 0.525. On the rainfall over 100mm, it was 0.673 and on the rainfall over 150mm, it was 0.641. The correlation between E-coli and rainfall was higher than that between bacteria and rainfall.

• Proceedings of the Korea Water Resources Association Conference
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• 2019.05a
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• pp.257-257
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• 2019

최근 기후변화에 따른 대응을 위해 기존 수자원 활용의 고도화 및 배수능력 증대를 위해 다양한 방안이 추진되고 있으며, 그에 따라 기존 개수로에 신규 수로를 연결하여 합류와 분류를 시키는 사례가 증가하고 있다. 특히 신규 개수로 연결을 위한 분류부 형상은 관련 설계기준, 분류유량의 규모, 해당 지점의 하상변동 경향, 지형여건, 흐름 분류시설 및 구조물의 형태(양수펌프장, 스크린이나 수문, 암거설치)와 같은 구조적 요인 등에 의해 달라지지만, 이와 관련된 연구가 매우 부족한 실정이다. 따라서 본 연구에서는 2차원 수치모형을 이용하여 분류부 평면형상 변화에 따른 분류유량비와 흐름분리구역 분포 등에 대한 흐름특성을 분석하고 이수와 치수계획 수립 등에 활용하고자 한다. 본 연구에서는 TELEMAC-2D 모형을 이용하여 주수로 상류 유입흐름의 프루우드 수가 0.74, 0.52인 두 흐름에 대해 형상변화 폭을 주수로 폭(B)의 1B, 주수로 형상변화를 급확대, 점진적 확대 구간길이를 1B~3B로 변화시키며 분류유량비(분류수로 유입유량/상류 유입유량)와 흐름분리구역의 위치와 크기 등에 대한 분석을 수행하였다. 분류부 상류 유입흐름의 프루우드 수가 0.74, 분류유량비는 0.33인 흐름은 주수로 형상변화 구간길이가 1B 일 때 0.44~0.46, 3B일 때 0.54~0.60으로 점차 분류유량비가 증가한다. 반면 상류 유입흐름의 프루우드수가 0.52, 분류유량비가 0.52인 흐름은 주수로 형상변화 구간길이가 1B일 때 0.77~0.82에서 3B일 때 0.70~0.80으로 점차 분류유량비 증가율이 감소하는 경향을 나타내게 된다. 주수로 형상변화 폭을 0.5B, 1B로 달리하여 수로 형상변화를 시킨 경우 분류유량비 증가율은 각각 135~162%, 134~176%로 나타났으며, 이는 수로 형상변화 폭보다 변화구간 길이가 더 큰 분류유량비 변화에 영향을 미치는 것을 확인할 수 있다. 흐름분리구역은 상류 유입흐름의 프루우드 수가 0.74인 경우 수로형상 변화구간과 분류수로 입구에 형성되지만, 상류유입흐름의 프루우드 수가 0.52인 경우 수로형상변화 구간과 주수로 하류에도 형성된다. 수치실험 결과 동일수로 폭 직사각형 $90^{\circ}$ 분류수로에서 분류부 평면형상의 변화에 따라 주수로 하류방향흐름의 관성력은 감소하는 반면 분류수로로 향하는 횡압력경사와 흐름분리구역 발생위치 변화로 인해 분류 수로내 통수능이 증가하여 분류유량비가 급격하게 증가하게 된다. 또한 분류부 상류 유입흐름의 관성력이 작은 경우 분류부 평면형상 변화시 주수로 하류방향에서도 흐름분리구역이 형성되고 주수로 종방향 수위가 상승함에 따라 분류흐름 계획수립 시 세심한 주의가 필요하다.

• Proceedings of the Korea Water Resources Association Conference
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• 2019.05a
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• pp.371-371
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• 2019

우리나라는 홍수기(6~9월)에 집중되는 기상패턴과 하천 중하류부에 발달된 도시의 개발특성으로 인하여 가장 중요한 자연재해 중 하나로 홍수 및 도시침수가 거론되고 있다. 과거 집중호우로 침수 피해가 발생한 사례를 살펴보면, 피해가 발생하는 지역은 지방하천 및 소하천을 중심으로 형성된 도시지역이다. 중앙 지방 정부는 수차례 침수 피해를 겪으며 사후관리가 아닌 재난예방 및 사전관리 등의 방안 마련을 강조하고 있다. 하지만 기후변화에 의한 기상의 불확실성으로 치수 중심의 물관리 및 중 소하천의 하천 특성으로 여전히 홍수 발생에 대비할 수 있는 골든타임 확보 등에 어려움을 겪고 있다. 이러한 어려움을 극복하기 위해 사전 예방적 차원에서의 홍수대응 방안으로 중 소하천을 담당하는 지자체 중심의 홍수피해 저감 방안이 필요하다. 본 연구에서는 A 지자체를 대상으로 모니터링 대상 경계를 설정하여 우량 알람 기준을 예비알람, 주요 관측지점에 대해 강우에 따른 수위 상승 정도를 홍수대응 기준인 직접알람과 연계함으로써 예방적 재난대응 체계를 구축하였다. 모니터링 대상 지역은 해당 지자체를 포함하면서 유역 개념을 적용하여 만경강유역 전체로 설정하였다. 만경강 유역 내 유관기관(지자체, 환경부, K-water, 기상청 등)이 관할하는 우량국(41개소) 및 수위국(28개소), 저수용량이 30만톤 이상이 되는 농어촌공사 저수지(7개소)를 고려하여 홍수분석 모형(COSFIM)을 구축하였다. 해당 모형은 2018년 8월 호우사상에 대해 주요 수위관측 지점에서 $R^2$가 0.8 이상의 우수한 검증 결과를 보였다. 구축된 모형을 통해 예상강우량별 하천 내 수위지점별 최고수위, 최대유량, 도달시간 등 예상 조견표를 제시하여 호우 발생시 지자체 담당자가 참고할 수 있도록 제시하였다. 또한 수위지점별 홍수대응 기준은 평시, 관심, 주의, 경계, 심각 단계로 구분하여 담당자가 수위별 위험 정도를 인지할 수 있도록 지점별 도달되는 수위의 위험 정보를 알람기준으로 제시하였다. 홍수분석 모형은 상류에 위치한 주요시설물의 운영현황을 연계하고 있어 실제 강우 발생 시 기상예보를 고려하여 하천 내 수위관측 지점별 수위 상승 정도를 예상함으로써 사전에 홍수에 대비할 수 있는 단계별 시간 확보에 활용 가능하다. 향후 홍수대응기준은 하천 환경 변화를 반영하여 지속적인 보완이 필요하며 유관기관과의 수문자료 공유체계 확대로 예방적 차원의 홍수 대응 체계가 구축되어야 할 것이다.

• Korean Journal of Ecology and Environment
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• v.41 no.3
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• pp.348-359
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• 2008

The objectives of the study were to elucidate functional modifications in relation to hydrological, physico-chemical and ecological aspects in Daechung Reservoir by the upper dam constructions of Youngdam Reservoir and analyze temporal and spatial dynamic patterns using trophic parameters of TN, TP, chlorophyll (CHL), and Secchi depth (SD). Hydrological data such as inflow, precipitation, and water levels before (BDC, 1995$\sim$2000) and after (ADC, 2001$\sim$2006) the dam construction showed that precipitation had greater correlations with inflow volume in the BDC (r=0.964, p=0.002) than in the ADC (r=0.857, p=0.029). This outcome indicates that the upper dam construction influenced the inflow and water level of Daechung Reservoir. One of the greatest changes after the dam construction was decreases of nutrient contents (TN, TP) and increases of algal biomass (as CHL) as the water residence time increases. Values of CHL had greater relations with TP in the ADC (r=0.412, p<0.001) than the BDC (r=0.249, p<0.001), indicating that CHL had greater response at a given phosphorus in the ADC. Thus, algal yield at a given TP (CHL : TP ratios) increased in the ADC, resulting in a greater CHL-TP relations. Long-term interannual TP, TN, SD, and CHL showed greater variations in the riverine zone (RZ) than any other transition (TZ) and lacustrine zones (LZ). This phenomenon was mainly attributed to rapid hydrological response in the riverine zone (RZ) to flow reductions (short water residence time) from the upper dam, resulting in ambient contents of nutrients and light regime along with functional relations of CHL-TP.

• Food Science of Animal Resources
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• v.25 no.4
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• pp.365-372
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• 2005

This study was carried out to investigate the Physiochemical Properties of loin and rump in the native horse meat from Jeju. In the analysis of chemical composition of loin and rump, the result showed $72.2\%\;and\;73.8\%$ in moisture content $20.1\%\;and\;21.2\%$ in crude protein, $2.42\%\;and\;3.08\%$ in crude Int and $0.13\%\;and\;0.14\%$ in crude ash respectively. Glutamic acid was 3,275mg/100g and 3,577mg/100g in loin and rump each and it had highest result in amino acid analysis. K content was 388.0mg/100g which showed highest result in mineral analysis and next contents were P>Na>Mg>Ca. Oleic acid had highest result in fatty acid composition which were $62.64\%\;and\;63.77\%$ in loin and rump respectively. Cholesterol content of loin and rump were 43.25 and 43.57 mg/100g but showed no significant differences to the part. pH of loin and rump were 5.60 and 5.75 which had no significant differences. Loin had Higher result than that of rump with no significant differences in WHC and springiness of texture analysis. Redness of rump was higher than that of loin. In the sensory evaluation, there were significant differences in the color and odor. Loin had higher result than that of rump in the overall palatability but showed no significant differences. With the result of this experiment native horse meat from Jeju could be understood as good meat resources.