• 제목/요약/키워드: Floods

검색결과 668건 처리시간 0.033초

홍수기 저수지의 최적연계운영 (The optimal operation of reservoir systems during flood season)

  • 한건연;최현구;김동일;이경택
    • 한국방재학회:학술대회논문집
    • /
    • 한국방재학회 2008년도 정기총회 및 학술발표대회
    • /
    • pp.743-746
    • /
    • 2008
  • Recently, due to the effect of global warming and extreme rainfall, the magnitude of flood disaster and the frequency of flood is rapidly increasing. In order to mitigate the damage of human and property from this kind of meteorological phenomenon and manage water resources scientifically, effective operation of dam and reservoir is very important. In case of Andong dam which was not performed a flood control function needs to develop new types of dam safety management measure because of recent extraordinary flood by typhoons. In case of Andong dam and Imha dam, I am using HEC-5 model in order to apply reservoir simulation. In this case, complex conditions among 100-year floods , 200-year floods and PMF was used. Also, I modified the maximum outflow 3,800m3/s into 3,490m3/s and applied this modified discharge in order to secure freeboard in the downstream. In an analysis that I applied modified outflow by 100-year floods and 200-year floods to, the result showed that river didn't overflow in Andong area but some other places have relatively low freeboard. In the cases that I modified maximum outflow, results showed that freeboard of levee is larger than existed simulation. In the simulation that I applied 200-year floods and PMF to and under a condition connected with PMF, results showed overflowing the levees. Because of the difference between the frequency of dam outflow and the design flood in river, it is required to improve the existed flood plan in the downstream of Andong dam. As a result of this study, the optimal operation of reservoir systems can be proposed to mitigate the flood damage in the downstream of Andong dam and also can be used to establish the flood plans.

  • PDF

Floods and Flood Warning in New Zealand

  • Doyle, Martin
    • 한국수자원학회:학술대회논문집
    • /
    • 한국수자원학회 2012년도 학술발표회
    • /
    • pp.20-25
    • /
    • 2012
  • New Zealand suffers from regular floods, these being the most common source of insurance claims for damage from natural hazard events in the country. This paper describes the origin and distribution of the largest floods in New Zealand, and describes the systems used to monitor and predict floods. In New Zealand, broad-scale heavy rainfall (and flooding), is the result of warm moist air flowing out from the tropics into the mid-latitudes. There is no monsoon in New Zealand. The terrain has a substantial influence on the distribution of rainfall, with the largest annual totals occurring near the South Island's Southern Alps, the highest mountains in the country. The orographic effect here is extreme, with 3km of elevation gained over a 20km distance from the coast. Across New Zealand, short duration high intensity rainfall from thunderstorms also causes flooding in urban areas and small catchments. Forecasts of severe weather are provided by the New Zealand MetService, a Government owned company. MetService uses global weather models and a number of limited-area weather models to provide warnings and data streams of predicted rainfall to local Councils. Flood monitoring, prediction and warning are carried out by 16 local Councils. All Councils collect their own rainfall and river flow data, and a variety of prediction methods are utilized. These range from experienced staff making intuitive decisions based on previous effects of heavy rain, to hydrological models linked to outputs from MetService weather prediction models. No operational hydrological models are linked to weather radar in New Zealand. Councils provide warnings to Civil Defence Emergency Management, and also directly to farmers and other occupiers of flood prone areas. Warnings are distributed by email, text message and automated voice systems. A nation-wide hydrological model is also operated by NIWA, a Government-owned research institute. It is linked to a single high resolution weather model which runs on a super computer. The NIWA model does not provide public forecasts. The rivers with the greatest flood flows are shown, and these are ranked in terms of peak specific discharge. It can be seen that of the largest floods occur on the West Coast of the South Island, and the greatest flows per unit area are also found in this location.

  • PDF

과거강우사상과 저류함수모형을 이용한 대유역 계획홍수량 추정 (Design Flood Estimation using Historical Rainfall Events and Storage Function Model in Large River Basins)

  • 윤종우;이동률;안원식;임해욱
    • 대한토목학회논문집
    • /
    • 제29권3B호
    • /
    • pp.269-279
    • /
    • 2009
  • 대유역에서 계획홍수량 추정은 ARF, 강우 시공간분포 및 강우-유출 모형의 매개변수 등에서 많은 불확실성이 발생한다. 과거 동시 강우사상을 이용한 계획홍수량의 추정은 이들 불확실성을 개선할 수 있다. 본 연구는 과거 동시 강우사상과 저류 함수모형을 이용하여 대유역의 홍수량을 추정하는 방법을 제시하였다. 과거 동시 강우사상의 시공간분포를 이용하여 계획 강우량과 강우의 시공간분포를 산정하였고 비선형 강우-유출 반응을 재현할 수 있는 저류함수모형을 이용하여 홍수량을 추정하였다. 추정된 계획홍수량은 실측홍수량에 의한 빈도분석 결과와 비교하여 본 연구에서 제시한 홍수량 추정기법의 적용성을 평가하였다. 본 연구의 결과는 실측홍수량의 빈도해석과 비슷한 결과를 얻었으며 이는 대유역의 홍수량 추정에서 본 연구의 홍수량 추정과정을 충분히 이용할 수 있음을 보여준다.

L-모멘트법에 의한 적정 설계홍수량의 유도 (Derivation of Optimal Design Flood by L-Moments)

  • 이순혁;박명근;맹승진;정연수;김동주;류경식
    • 한국농공학회:학술대회논문집
    • /
    • 한국농공학회 1998년도 학술발표회 발표논문집
    • /
    • pp.318-324
    • /
    • 1998
  • This study was conducted to derive optimal design floods by Generalized Extreme-value(GEV) distribution for the annual maximum series at ten watersheds along Han, Nagdong, Geum, Yeongsan and Seomjin river systems. Adequacy for the analysis of flood data used in this study was established by the tests of Independence, Homogeneity, detection of Outliers. L-coefficient of variation, L-skewness and L-kurtosis were calculated by L-moment ratio respectively. Parameters were estimated by the Methods of Moments and L-Moments. Design floods obtained by Methods of Moments and L-Moments using different methods for plotting positions in GEV distribution were compared by the relative mean and relative absolute error. It was found that design floods derived by the method of L-moments using weibull plotting position formula in GEV distribution are much closer to those of the observed data in comparison with those obtained by method of moments using different formulas for plotting positions in view of relative mean and relative absolute error.

  • PDF

Weibull-3 분포모형의 모멘트법 및 L-모멘트법에 의한 홍수빈도비교분석 (Comparative Analysis of Flood Frequncy by Moment and L-moment in Weibull-3 distribution)

  • 이순혁;맹승진;송기헌;류경식;지호근
    • 한국농공학회:학술대회논문집
    • /
    • 한국농공학회 1998년도 학술발표회 발표논문집
    • /
    • pp.331-337
    • /
    • 1998
  • This study was carried out to derive optimal design floods by Weibull-3 distribution with the annual maximum series at seven watersheds along Man, Nagdong, Geum, Yeongsan and Seomjin river systems. Adequacy for the analysis of flood data used in this study was acknowledged by the tests of Independence, Homogeneity, detection of Outliers. Parameters were estimated by the Methods of Moments and L-Moments. Design floods obtained by Methods of Moments and L-Moments using different methods for plotting positions in Weibull-3 distribution were compared by the rotative mean error and relative absolute error. It has shown that design floods derived by the method of L-moments using Weibull plotting position formula in Weibull-3 distribution are much closer to those of the observed data in comparison with those obtained by method of moments using different formulas for plotting positions in view of relative mean and relative absolute error.

  • PDF

Log Pearson Type III 분포 모형에 의한 매개변수 유도방법별 설계홍수량의 비교 고찰 (Comparative Studies on the Design Floods Derived by Different Methods for the Parameters of the Log Pearson Type III Distribution)

  • 이순혁;정연수;맹승진;유경식
    • 한국관개배수논문집
    • /
    • 제4권1호
    • /
    • pp.34-50
    • /
    • 1997
  • This study was conducted to derive optimal design floods by Log Pearson Type III distribution model of the annual maximum series at five watersheds along Geum, Yeong San and Seom Jin river systems. Design floods obtained by different methods for evaluatio

  • PDF

일부 남자 고등학교 태권도 선수들의 영양상태와 식이 조사 시점 및 조사 일수의 평가 (An Evaluation of the Nutritional Status and the Desirable Time and Period for Dietary Record in Male High School Taekwondo Athletes)

  • 정경아;황세희;김찬;이장규;장유경
    • Journal of Nutrition and Health
    • /
    • 제35권2호
    • /
    • pp.237-249
    • /
    • 2002
  • This study was done to evaluate the nutritional status and the desirable time and period for making dietary records in male high school Taekwondo athletes. Nutrient and flood intake was investigated using dietary record method during usual training (UT, for 29 days) and special training (ST, for 17 days) periods in nine Taekwondo athletes. Nutrient intake by 7-d and 3-d dietary record were compared to the standard nutrient intake, which was computed from dietary record during total period of UT or ST. Total mean energy intake was 2278 kcal, 84% of RDA, and mean intakes of riboflavin, Ca and Fe were less than 77% of RDA. Mean intakes of energy, carbohydrate, protein, fat, cholesterol, thiamin, riboflavin, and P decreased during ST (p < 0.05 or p < 0.01). Mean intakes of vegetables and grains ware the highest in the two periods and following were beverages and instant floods in UT, and meats and fruits in ST. During ST, mean intakes of mushrooms, meats and their products, and instant floods decreased, and sugars and sweets increased (p < 0.05 or p < 0.01). The contribution of grains and their products, instant floods, and meats and their products to mean intakes of energy, carbohydrate, protein and fat were high. In snacks, the contribution of instant floods, breads and confections and beverages was high. During UT, cholesterol intake at weeks 1 and 3, and intakes of protein, fat, thiamin, riboflavin and niacin at week 4 by 7-d dietary record were different from their standard intakes (p < 0.05 or p < 0.01). Intakes of VA, Ca and Fe at week 1, and intakes of carbohydrates, cholesterol rind crude fiber at week 4 by 3-d dietary record were different from their standard intakes (p < 0.05 or p < 0.01). During ST, VC intake at week 5, and energy intake from carbohydrate and cholesterol intake at week 6 by 7-d dietary record were different from their standard intakes (p < 0.05 or p < 0.01). Cholesterol intake at week 7, and energy intake from carbohydrates and fat, and intakes of protein, fat, cholesterol and riboflavin by 3-d dietary record were different from their standard intakes (p < 0.05 o. p < 0.01). In conclusion, empty-calorie floods can be a main source of diet and snacks for Taekwondo athletes, and education about desirable nutrients and floods intakes is needed to help them control their weight. When investigating the nutritional status of Taekwondo athletes in the future, the 7-day or 3-day dietary record is desirable provided they are conducted in the milddle of each period artier distinguishing UT from ST period.

Generalized Gamma 분포 모형의 매개변수 유도 방법에 의한 설계홍수량의 비교분석 (Comparative Analysis of Design Flood by Different Methods for the Estimation of Parameters in Generalized Gamma Distribution Model)

  • 이순혁;맹승진;류경식
    • 한국관개배수논문집
    • /
    • 제5권1호
    • /
    • pp.32-46
    • /
    • 1998
  • This study was conducted to derive optimal design floods by generalized gamma distribution model of the annual maximum series at six watersheds along Han and Nag Dong river systems. Design floods obtained by different methods for estimation of parameters

  • PDF

Scenario Analysis Technology for Flood Risk Management in the Taihu Basin

  • Changwei, Hu
    • 한국수자원학회:학술대회논문집
    • /
    • 한국수자원학회 2010년도 학술발표회
    • /
    • pp.140-148
    • /
    • 2010
  • The Taihu Basin is located in the east coast of China, where the threats of frequent floods have induced construction of massive, complex, hierarchical flood defense systems over the interconnected river networks. Digital modeling of flooding processes and quantitative damage assessment still remain challenging due to such complexity. The current research uses an integrated approach to meet this challenge by combining multiple types of models within a GIS platform. A new algorithm is introduced to simulate the impacts of the flood defense systems, especially the large number of polders, on floods distributions and damages.

  • PDF

L-모멘트 및 LH-모멘트 기법에 의한 적정 설계홍수량의 유도( I ) - L-모멘트법을 중심으로 - (Derivation of Optimal Design Flood by L-Moments and LB-Moments ( I ) - On the method of L-Moments -)

  • 이순혁;박명근;맹승진;정연수;김동주;류경식
    • 한국농공학회지
    • /
    • 제40권4호
    • /
    • pp.45-57
    • /
    • 1998
  • This study was conducted to derive optimal design floods by Generalized Extreme Value (GEV) distribution for the annual maximum series at ten watersheds along Han, Nagdong, Geum, Yeongsan and Seomjin river systems. Adequacy for the analysis of flood data used in this study was established by the tests of Independence, Homogeneity, detection of Outliers. L-coefficient of variation, L-skewness and L-kurtosis were calculated by L-moment ratio respectively. Parameters were estimated by the Methods of Moments and L-Moments. Design floods obtained by Methods of Moments and L-Moments using different methods for plotting positions in GEV distribution were compared by the Relative Mean Errors(RME) and Relative Absolute Errors(RAE). The results were analyzed and summarized as follows. 1. Adequacy for the analysis of flood data was acknowledged by the tests of Independence, Homogeneity and detection of Outliers. 2. GEV distribution used in this study was found to be more suitable one than Pearson type 3 distribution by the goodness of fit test using Kolmogorov-Smirnov test and L-Moment ratios diagram in the applied watersheds. 3. Parameters for GEV distribution were estimated using Methods of Moments and L-Moments. 4. Design floods were calculated by Methods of Moments and L-Moments in GEV distribution. 5. It was found that design floods derived by the method of L-Moments using Weibull plotting position formula in GEV distribution are much closer to those of the observed data in comparison with those obtained by method of moments using different formulas for plotting positions from the viewpoint of Relative Mean Errors and Relative Absolute Errors.

  • PDF