• Journal of Korean Society on Water Environment
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• v.27 no.4
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• pp.509-515
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• 2011

For this study the 4 sub-watersheds Okdong A, Hankang B, Jecheon A and Hankang C which are the main streams of the Han River within the mid-level region of Chungju Dam are selected and the analysis of soils has been carried out through the soil basic survey. When it comes to the soil erosion amount the soil nutrient load has been calculated by utilizing the RUSLE erosion equation. In case of the data related to the measurement of water flow and quality the information available from the "Water Information System" one of the websites run by the Ministry of Environment has been used to calculate the water pollution load. The correlation between the soil nutrient load and the water pollutant load has been analyzed through making comparison. According to the results related to the soil nutrient load of each sub-watershed the Hankang C shows the highest values TOC 29,986.92 ton/yr, TN 3,860.33 ton/yr and TP 973.97 ton/yr respectively. Even when it comes to the loads related to water quality the Hankang C shows also comparatively high values TOC 6,625.64 ton/yr, TN 7,335.01 ton/yrand TP 145.49 ton/yr respectively. The soil nutrient loads of the sub-watersheds are shown to increase towards the lower stream meaning the load increases in the order of Hankang CHankang B and Okdong A. When it comes to the water pollutant load the value goes up along down the water system meaning the load gets higher in the order of Hankang C, Hankang B and Okdong A while utilizing the mainstream within the mid-level region of Chungju Dam as the basis. The correlation study showed that the nutrient content of soil is proportional to the pollutant load in water with the strongest positive correlation with TOC.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.18 no.2
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• pp.157-165
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• 1985

Character of oceanic conditions in the bay is investigated by taking hydrographic data on june in Kamak Bay which has two channels and four submarine topographic parts of its own. This bay has four remarkable water mass influenced greatly by the above topographical factor: inner bay water, Yosu harbor water, the middle water and outer bay water. General characteristics of these four water mass were as fellows: inner bay water has a stagnation character with the influence of inland, Yosu harbor water has a out-sea character with the low salinity caused by run-off of Somjin river, outer bay water has a out-sea character with same values vertically coused by eddy current or bottom turbulunce and the middle water has a middle character among the inner bay water and outer bay water. Outer waters flowed in the bay through both channels during the flood are come upon at a near by Daekyong-do and Hangdae-ri of Dolsan-do. Eddy current or bottom turbulunce in the vincinity of Kunnae-ri which is located at south of the bay are showed sinking of water during the flood flow, while that during the ebb flow shelved up-welling phenomena.

• Proceedings of the Korean Quaternary Association Conference
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• 2004.11a
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• pp.37-43
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• 2004

The response of the CCCma coupled climate model to the imposition of LGM conditions is investigated. The global mean SAT and SST decrease by about $10^{\circ}C$ and $5.6^{\circ}C$ in the coupled model. Tropical SST decreases by $6.5^{\circ}C$, whereas CLIMAP reconstructions suggest that the tropics cool by only about $1.7^{\circ}C$, although the larger tropical cooling is consistent with the more recent proxy estimates. With the incorporation of a full ocean component, the coupled model gives a realistic spatial SST pattern, capturing features associated with ocean dynamics that are seen in the CLIMAP reconstructions. The larger decrease of the surface temperature in the model is associated with a reduction in global precipitation rate (about 15%). The tropical Pacific warm pool retreats to the west and a mean La $Ni\tilde{n}a$-like response is simulated with less precipitation over the central Pacific and more in the western tropical Pacific. The more arid ocean climate in the LGM results in an increase in SSS almost everywhere. This is particularly the case in the Arctic Ocean where large SSS increase is due to a decrease in river discharge to the Arctic Ocean associated with the accumulation of snow over the ice sheet, but in the North Atlantic by contrast SSS decreases markedly. This remarkable reduction of SSS in the North Atlantic is attributed to an increase in fresh water supply by an increase in discharges from the Mississippi and Amazon rivers and an increase in P-E over the North Atlantic ocean itself. The discharges increase in association with the wetter LGM climate south of the Laurentide ice sheet and in South America. The fresh water capping of the northern North Atlantic results in a marked reduction of deep convection and consequently a marked weakening of the North Atlantic overturning circulation. In the LGM, the maximum overturning stream function associated with the NADW formation decreases by about 60% relative to the control run, while in the Southern Ocean, oceanic convection is stronger in the LGM due to reduced stratification associated with an increase in SSS and a decrease in SST and the overturning stream function associated with the formation of AABW and the outflow increases substantially.

• Journal of Korea Water Resources Association
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• v.41 no.7
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• pp.737-746
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• 2008

The purpose of developing a rainfall-runoff and reservoir model is to provide an analysis tool for hydrological engineers in order to forecast discharge of rivers and to accomplish reservoir operations easily and accurately. In this study, based on the short-term rainfall-runoff storage function model which has gained popularity for real time flood forecast in practical water management affairs, a long-term runoff model was developed for the improvement of the calculation method of effective rainfall and percolation at the infiltration area. Annual discharge was simulated for three dam watersheds(Andong, Hapcheon, Milyang) in Nakdong River basin to analyze the accuracy of the developed model and compare it to SSARR model, which is used as the long-term runoff model in current practical water management affairs. As the result of the comparison of hydrographs, SSARR model showed relatively better results. However, it is possible for the developed model to simulate reliable long-term runoff using relatively little available data and is useful for hydrological engineers in practical affairs.

• Journal of Korea Water Resources Association
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• v.47 no.12
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• pp.1177-1185
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• 2014

This study suggests a new hydrostatic pressure distribution corrected for nonuniform flow over a channel of large slope. For analyzing shallow-water flows over large slope accurately, it is developed a finite-volume model incorporating the pressure distribution to the shallow water equations. Traveling speed of the hydraulic jump downstream a parabolic bump in the drain case is quite reduced by the weakened bottom gradient source term in the model with the pressure correction. In simulating the dam-break flow over a triangular sill, it is identified that the model with pressure correction could capture the water surface by the digital imaging measurements more than the model without that. Due to the pressure correction decreasing the reflected flows on and increasing overflows over the sill, there are good agreements in the experiment and the simulation with that. Therefore, this model is expected to be applied to such practical problems as flows in the spillway of dam or run-up on the beach.

• Proceedings of the Korea Water Resources Association Conference
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• 2018.05a
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• pp.227-227
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• 2018

티롤리안 위어(Tyrolean Weir)는 유송잡물 및 유사의 영향이 비교적 높은 산악지역에 설치되는 취수구조물로 대부분 저류면적이 제한된 자류식(Run-Off River) 수력발전 및 소규모 농업용수 취수시설에 적합한 구조물이다. 티롤리안 위어는 일반적인 취수시설과 비교하여 구조물의 규모를 최소화할 수 있어 친환경적 취수구조물로 분류할 수 있다. 아직까지 국내에서는 설치사례가 없고 연구성과 또한 부족하여 적용성에 한계가 있는 것이 사실이다. 본 연구에서는 3차원 유동해석 프로그램인 FLOW-3D를 이용하여 티롤리안 위어의 월류흐름특성을 분석하고 스크린 경사와 월류수위 변화에 따른 유량계수를 산정하였다. 티롤리안 위어 스크린경사에 따른 수치모형실험을 위해 3차원 AUTO CAD 프로그램을 이용하여 위어폭 11.0m, 길이 10m 및 수로경사 2:3의 솔리드 모형을 구성하였으며, 티롤리안 위어 스크린 경사를 $0^{\circ}$, $5^{\circ}$, $10^{\circ}$, $15^{\circ}$, $20^{\circ}$, $25^{\circ}$, $30^{\circ}$로 변화시키며 월류수심 변화에 따른 수치모형실험을 수행하였다. 금회 수치해석 분석결과 다음과 같은 결론을 얻을 수 있었다. 1) 티롤리안 위어 스크린 경사가 증가할수록 유량계수가 증가하였다. 2) 월류수심 1.4m일때 월류량의 표준편차는 0.767이며 월류수심 4.4m일때 표준편차는 9.580으로 월류수심이 증가할수록 스크린 경사에 따른 표준편차는 증가하는 것으로 확인되었다. 3) 티롤리안 위어 스크린 경사가 클수록 월류수심은 감소하고 접근수로부 유속이 증가하였으며 스크린 경사가 작을수록 월류수심은 증가하고 유속이 감소하는 경향을 확인하였다. 4) 티롤리안 위어 스크린 경사가 작고 월류수심이 클수록 광정위어와 유사한 흐름특성을 보였다.

• Proceedings of the Korea Water Resources Association Conference
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• 2010.05a
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• pp.1555-1559
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• 2010

본 연구는 미래 물 관리를 위한 기후변화 대응방안 도출 연구의 사전연구로서 금강유역의 과거 기상 수문요소의 특성변화 분석을 수행하였다. 기상자료로 금강유역 기상관측소 8개소의 37개년(1973~2009)의 기온, 강수량, 상대습도 자료를 수집하였다. 하천수위자료는 수위자료와 수위-유량관계곡선의 신뢰성 문제, 이후 수행될 장기유출분석을 고려하여 최종적으로 공주, 규암 수위관측소의 36개년(1973~2008)의 자료를 이용하였고, 지하수위자료는 강우관측소와 근접하게 위치해 있으면서 과거 자료를 최대한 많이 보유하고 있는 6개 관측소의 10개년(1999~2008)의 자료를 이용하였다. 수집된 자료의 평균, 표준편차, 왜곡도, 변동계수를 산출하여 연 계절별로 수문기상인자의 경년변화를 파악한 결과 기상인자 중 강수량의 변동성이 가장 크게 나타나 경년별 변화가 큰 것으로 분석되었고 하천수위보다는 지하수위가 경년별 변동이 적은 것으로 분석되었다. 수문학적 지속성 분석을 위해 Run 검정, Turning Point 검정, Anderson Exact검정을 이용하여 시계열자료에 주기성이 있는지 분석한 결과 기온과 강수는 무작위성, 상대습도, 하천수위는 지속성을 가지는 인자로 분석되었고 지하수위는 관측소별, 기간별로 무작위성과 지속성이 혼재되어 있는 것으로 나타났다. 마지막으로 경향성 분석을 위해 단순 선형 회귀분석과 Mann-Kendall 검정을 이용하였다. 그 결과 기온은 연 계절 모두 증가경향이 나타났고, 강수량은 여름에만 증가경향이 나타났으며, 상대습도는 뚜렷한 감소경향을 보였다. 또한 하천수위는 감소경향이 나타났으며 지하수위는 유의수준 범위에서 경향성은 보이지 않았다. 본 연구의 결과는 기후변화로 인해 발생될 수 있는 수자원의 영향을 평가하고 미래 물 관리 적응기술 개발 및 계획 수립을 위한 자료로 활용될 수 있을 것으로 사료된다.

• Proceedings of the Korea Water Resources Association Conference
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• 2023.05a
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• pp.471-471
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• 2023

소양댐 상류 유역에 위치한 고랭지 밭에서 강우시 많은 양의 탁수가 유입되고 있어 상·하류지역사회에 갈등을 유발하고 하천 환경오염의 주범으로 지목되었다. 이에 환경부는 2007년부터 꾸준히 소양호 유역을 비점오염원 관리지역으로 지정하여 다양한 노력을 기울여왔으나 여전히 소양강 상류 수계의 강우시 흙탕물 발생이 지속적으로 문제가 되고 있다. 특히 고랭지 농업이 활발한 자운지구의 경우 고랭지 밭 경작 이외에도 나대지 상태로 방치되거나, 절삭지 보호가 제대로 이루어지지 않는 등 여러 가지 문제로 토사유출이 심각하게 발생하고 있어 흙탕물 관리가 필요한 실정이다. 이에 본 연구에서는 자운지구를 포함한 내린천 유역을 대상으로 강우유출수 모니터링을 수행하였으며, 모니터링 결과를 바탕으로 강우시 비점오염물질 유출 특성을 분석하였다. 강우유출수 모니터링은 2022년 3월부터 10월 중 총 5회를 수행하였으며, 내린천 유역 내 유량 측정망이 설치되어 있는 4개지점(양지교, 현리교, 하죽천교, 원대교)과 내린천 상류 2개지점(에코빌리지, 새터교) 총 6개 지점에서 강우유출수 모니터링을 실시하였다. 분석된 자료를 바탕으로 각 소유역별 EMC, 오염부하, 단위면적당 오염부하를 산정한 결과 하죽천교와 원대교의 단위면적 당 오염부하가 높게 나타났다. 이는 해당 소유역(내린천 하류)에서 발생한 강우강도가 상류에 비해 높았으며, 하죽천교는 유역내 농경지의 비율이 높고, 원대교는 가파른 경사도의 영향이 큰 것으로 판단된다. 또한, 하죽천교와 원대교 소유역에서 배출된느 흙탕물이 내린천 유역의 하천수질 오염에 상당한 기여를 하고 있는 것으로 나타났으며, 오염 우심 소유역에서 발생하는 흙탕물 저감을 위한 적절한 대책이 마련되어야 할 것으로 판단된다. 본 연구 결과와 같이 장기적인 모니터링을 통해 내린천 유역의 흙탕물 저감 대책 수립을 위한 기초자료로 활용할 수 있을 것으로 기대된다.

• Magazine of the Korean Society of Agricultural Engineers
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• v.30 no.2
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• pp.31-43
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• 1988

The Purpose of this study is to develop the rainfall-delayed response model (RDR Model) which influences the baseflow proportion of rivers as a result of the antecedent precipitation of the previous several months. The assesment of accurate baseflows in the rivers is one of the most important elements for the planning of seasonal water supply for agriculture, water resources development, hydrological studies for the availability of water and design criteria for various irrigation facilities. The Palukan river gauging site which is located in the Pulukan catchment on Bali Island, Indonesia was selected to develop this model. The basic data which has been used comprises the available historic flow records at 19 hydrologic gauging stations and 77 rainfall stations on Bali Island in the study. The methology adopted for the derivation of the RDR model was the water balance equation which is commonly used for any natural catcbment ie.P=R+(catchment losses) -R+(ET+DP+DSM+DGW). The catchment losses consist of evapotranspiration, deep percolation. change in soil moisture, and change in groundwater storage. The catchment areal rainfall has been generated by applying the combination method of Thiessen polygon and Isohyetal lines in the studies. The results obtained from the studies may be summarized as follows ; 1. The rainfall-runoff relationship derived from the water balance equation is as shown below, assuming a relationship of the form Y=AX+B. Finally these two equations for the annual runoff were derived ; ARO$_1$=0.855 ARF-821, ARF>=l,400mm ARO$_2$=0.290ARF- 33, ARF<1,400mm 2. It was found that the correction of observed precipitation by a combination of Thiessen polygons and Isohyetal lines gave good correlation. 3. Analysis of historic flow data and rainfall, shows that surface runoff and base flow are 52 % and 48% (equivalent to 59.4 mm) of the annual runoff, respectively. 4. Among the eight trial RDR models run, Model C provided the correlation with historic flow data. The number of months over which baseflow is distributed and the relative proportions of rainfall contributing in each month, were estimated by performing several trial runs using data for the Pulukan catchment These resulted in a value for N of 4 months with contributing proportions of 0.45, 0.50, 0.03 and 0.02. Thus the baseflow in any month is given by : P$_1$(n) =0.45 P(n) +0.50 P(n-I ) +0.03 P(n-$_2$) +0.02 P(n-$_3$) 5. The RDR model test gave estimated flows within +3.4 % and -1.0 % of the observed flows. 6. In the case of 3 consecutive no rain months, it was verified that 2.8 % of the dependable annual flow will be carried over the following year and 5.8 % of the potential annual baseflow will be transfered to the next year as a result of the rainfall-delayed response. The results of evaluating the pefformance of the RDR Model was generally satisfactory.

• The Journal of Korean Philosophical History
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• no.31
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• pp.321-346
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• 2011

This is a preliminary study in order to deal intensively with the overall characteristics of Korean military science in the future days. First off, the history of military science of China based on the precedent studies was recapitulated, and a comparative study on the acceptance process of the books on military art and science, as well as on understanding patterns of literati on the subject through literature searches, ranging from the Three Kingdoms Period to the Goryeo Dynasty in Korean peninsula, was conducted. In case of Korea, the Chinese books on military strategy, including Sun Tzu's the Art of War, had already been passed down during the Three Kingdoms Period, and broadly read by scholarly people. They had utilized diverse methods based on their knowledge of Confucianism. In the reference materials, the authors of Korean military strategy books had greatly relied upon the Chinese books on military strategies, however, they had made the military principles run in their own way. At the end of Goryeo Dynasty, 'Military Science' had been well established as a subject in academia, and this curriculum had been taught not only at the National Confucian Academy, Seonggyun-gwan, in the capital but also at the country public school ("Hyanggyo") in the province together with Confucianism. Because of the limits of reference materials, however, it was difficult to confirm whether or not such strategic experiences were actually led to the publication of the books on military art and science, or how many books on military strategies and tactics had been published up until the end of Goryeo Dynasty. But, the facts that there were not many publications of the books on military strategies during the era of Three Kingdoms and of Goryeo Dynasty don't mean that Korean military science had entirely relied upon the Chinese military art and science. For instance, such strategies, tactics and leaderships as exhibited in the process of the Great Victory at Salsu River ("Salsu Daecheop") achieved by General Eulji Mun-deok, as well as the Great Victory at Gwiju ("Gwiju Daecheop") achieved by General Kang Gam-chan could never happen by chance.