• 제목/요약/키워드: Floods

검색결과 668건 처리시간 0.035초

INFLOW PREDICTION FOR DECISION SUPPORT SYSTEM OF RESERVOIR OPERATION

  • Kazumasa Ito
    • 한국수자원학회:학술대회논문집
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    • 한국수자원학회 2002년도 학술발표회 논문집(I)
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    • pp.59-64
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    • 2002
  • An expert system, to assist dam managers for five dams along the Saikawa River, has been developed with a primary objective of achieving swift and accurate reservoir operation decision-makings during floods. The expert system is capable of supporting on decision-makings upon establishment of flood management procedure and release/storage planning. Furthermore, an attempt was made to improve reservoir inflow prediction models for better supporting capability. As a result, accuracy on prediction of inflow up to 7 hours ahead was improved, which is important for flood management of the five dams, using neural network. The neural network inflow prediction models were developed for each types of floods caused by frontal rainfalls, snowmelt and typhoons, after extracting relevant meteorological factors for each.

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Weibull-3및 GEV 분포모형의 L-모멘트법에 의한 홍수빈도 비교분석 (Comparative Analysis of Flood Frequency by L-moment in Weibull-3 and GEV Distributions)

  • 이순혁
    • 한국농공학회지
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    • 제41권4호
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    • pp.25-29
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    • 1999
  • This study was conducted to derive optimal design floods by Gerneralized Extreme Value(GEV) and Weibull-3 distributions for the annual maximum series at ten watersheds along Han,Nagdong, Geum, Yeongsan and Seomjin reiver systems. Adequency for the analysis of flood data used in this study was established by the tests of Independence. Homogeneity , detection of Outlines, L-moments. Design flood sobtaine dby /methods of Moments and L-Moments using different methods for plotting positions in BEV and Weibull-3 distributions were compared by the Relative Mean Errors(RME) and Root MEan Square Errors(RMSE). The result wa found that design floods derived by the L-moments using the other formulas for plotting positions from the viewpoint of Relative Mean Errors and Root Mean Square Errors.

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홍수시 얕은기초의 세굴위험도 평가 사례연구 (A Case Study of Scour Vulnerability Evaluation for Shallow Foundations during Floods)

  • 박재현;이주형;정문경;곽기석
    • 한국방재학회:학술대회논문집
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    • 한국방재학회 2008년도 정기총회 및 학술발표대회
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    • pp.59-62
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    • 2008
  • Scour vulnerability evaluation for shallow foundations was performed to assure bridge safety against scour in the national capital region. The case studies for 26 shallow foundations consisted of site investigation including boring test, bridge scour analysis for the design flood, bearing capacity evaluation of the bridge foundation before and after scour, and comprehensive evaluation of bridge scour vulnerability. Bridge scour vulnerability was determined based on the interdisciplinary concept considering predicted scour depth for the design floods and bearing capacity of foundation as well as dimensions of foundation. Nine of 26 shallow foundations showed the potential future vulnerability to scour with significant decrease in the bearing capacity of foundations due to scour and the remaining 17 were expected to maintain their stability against scour.

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2002년 8월의 집중호우와 저온현상 (Agricultural Implications of Rainfall Events and Low Temperature in August 2002)

  • 이양수;심교문;황규홍;고문환
    • 한국농림기상학회지
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    • 제4권3호
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    • pp.169-174
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    • 2002
  • When the long - lasting stationary fronts were pushed northward by the Pacific Highs in late July, mostly clear skies with intermittent showers were a typical weather of August in Korea. However, torrential rains and flash floods are now a seasonal event of August in recent years. Some meteorologists suspect this unusual phenomenon might be connected with the global change and are concerned about the possibility of change in summer climatic pattern in Korea. August of year 2002 must be remembered to be one of the record breaking months with respect to the rainfall events. In this paper, we analyzed the weather and crop data nationwide for August in 2002, and suggest a few countermeasures necessary to overcome the wet and cool summer impacts on agricultural sector.

Recurrent Neural Network with Multiple Hidden Layers for Water Level Forecasting near UNESCO World Heritage Site "Hahoe Village"

  • Oh, Sang-Hoon
    • International Journal of Contents
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    • 제14권4호
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    • pp.57-64
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    • 2018
  • Among many UNESCO world heritage sites in Korea, "Historic Village: Hahoe" is adjacent to Nakdong River and it is imperative to monitor the water level near the village in a bid to forecast floods and prevent disasters resulting from floods.. In this paper, we propose a recurrent neural network with multiple hidden layers to predict the water level near the village. For training purposes on the proposed model, we adopt the sixth-order error function to improve learning for rare events as well as to prevent overspecialization to abundant events. Multiple hidden layers with recurrent and crosstalk links are helpful in acquiring the time dynamics of the relationship between rainfalls and water levels. In addition, we chose hidden nodes with linear rectifier activation functions for training on multiple hidden layers. Through simulations, we verified that the proposed model precisely predicts the water level with high peaks during the rainy season and attains better performance than the conventional multi-layer perceptron.

이상기후변화가 낙동강 유역의 수문·수질요소에 미치는 영향 (Hydrologic and Water Quality Responses to Precipitation Extremes in Nakdong River Basin)

  • 장재호;안종호
    • 한국수자원학회논문집
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    • 제45권11호
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    • pp.1081-1091
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    • 2012
  • 가뭄, 홍수와 같은 이상기후에 따른 낙동강 유역의 수문과 수질에 미치는 영향을 평가하기 위해 강우 시나리오기반의 장기유출 유역모의를 통해 지표유출과 오염부하량 발생 특성을 살펴보았다. 전반적으로가뭄년도에서는지표유출량감소에 따라 오염부하량 감소현상을, 홍수년도에는 강우유출 증가에 따른 부하량 증가를 나타냈으나, 상류유역의 댐 직 하류와 같은 특정유역에서는 가뭄 시 댐 운영으로 인한 방류효과와 토양수분량의 변화 등의 물리적 요인들로 인해 SS부하량의 증가현상이 나타났다. 가뭄에 따른 SS의 농도변화는 유량변화에 따라 민감하게 반응하여 가뭄년도의 평수량 및 갈수량 시기에 높은 농도분포를 나타내었고 T-P는 상대적으로 본류구간보다는 유량이 비교적 적은 지류구간에서 높은 농도범위를 나타내었다. 반면, 홍수년도의 경우SS와T-P 모두 기준년도와 유사한농도범위에서 완만한형태의 변화를보였다. 또한, 유출량이 적은 건기 시에는 SS 부하량 유출도 감소하지만 유출량이 증가할수록 부하량이 급격히 증가하는 반면, T-P의 경우 건기 시에 부하량 유출이 크고 강우 시에는 오히려 감소하여 건기일수와 강우패턴에 지배적으로 각기 다른 영향을 받는 것으로 판단된다.

비용편익 분석을 통한 소하천유역의 저류조 설치 타당성 분석연구 (Using Cost-Benefit Analysis for a Feasibility Study on Constructing a Storage Facility in the Small River Basin)

  • 서세덕;이승욱;박형근
    • 대한토목학회논문집
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    • 제36권1호
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    • pp.135-141
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    • 2016
  • 본 연구의 목적은 소하천유역의 홍수와 가뭄 예방을 목적으로 설치하는 저류조에 대하여 비용 편익분석을 통해 경제적 타당성을 분석하는데 있다. 소하천유역의 홍수예방이 가능한 저류조 용량에 따른 설치비용을 도출하고, 저류조 설치를 통해 도출될 수 있는 편익요소인 피해금액 및 복구금액, 가뭄예방으로 인한 요소별 편익비용을 적용하여 비용 편익분석을 실시하였다. 이는 홍수와 가뭄을 동시에 예방할 수 있는 다목적 저류조 설치의 타당성을 제시하는 기초자료로 활용할 수 있으며, 세부 연구결과로 자연재해의 피해금액 예측 등 다방면으로 활용할 수 있을 것으로 기대된다.