• Title/Summary/Keyword: Probable Maximum Flood

Search Result 55, Processing Time 0.024 seconds

Modeling Downstream Flood Damage Prediction Followed by Dam-Break of Small Agricultural Reservoir (농업용 소규모 저수지의 붕괴에 따른 하류부 피해예측 모델링)

  • Park, Jong-Yoon;Joh, Hyung-Kyung;Jung, In-Kyun;Jung, Kwan-Soo;Lee, Joo-Heon;Kang, Bu-Sik;Yoon, Chang-Jin;Kim, Seong-Joon
    • Journal of The Korean Society of Agricultural Engineers
    • /
    • v.52 no.6
    • /
    • pp.63-73
    • /
    • 2010
  • This study is to develop a downstream flood damage prediction model for efficient confrontation in case of extreme and flash flood by future probable small agricultural dam break situation. For a Changri reservoir (0.419 million $m^3$) located in Yongin city of Gyeonggi province, a dam break scenario was prepared. With the probable maximum flood (PMF) condition calculated from the probable maximum precipitation (PMP), the flood condition by dam break was generated by using the HEC-HMS (Hydrologic Engineering Center - Hydrologic Modeling System) model. The flood propagation to the 1.12 km section of Hwagok downstream was simulated using HEC-RAS (Hydrologic Engineering Center - River Analysis System) model. The flood damaged areas were generated by overtopping from the levees and the boundaries were extracted for flood damage prediction, and the degree of flood damage was evaluated using IDEM (Inundation Damage Estimation Method) by modifying MD-FDA (Multi-Dimensional Flood Damage Analysis) and regression analysis simple method. The result of flood analysis by dam-break was predicted to occurred flood depth of 0.4m in interior floodplain by overtopping under PMF scenario, and maximum flood depth was predicted up to 1.1 m. Moreover, for the downstream of the Changri reservoir, the total amount of the maximum flood damage by dam-break was calculated nearly 1.2 billion won by IDEM.

A Study of Adoption on the Concept of Monthly Probable Maximum Precipitation (월 PMP 개념의 적용에 관한 연구)

  • Choi, Han-Kyu;Kim, Nam-Won;Choi, Yong-Mook;Yoon, Hee-Sub
    • Journal of Industrial Technology
    • /
    • v.21 no.B
    • /
    • pp.241-248
    • /
    • 2001
  • Normally at a flood season the operation of the dam depends on a short range weather forecast that makes many difficulties of the management at a dry season. It is needed to study the pattern of the long period rainfall. The concept of PMP(Probable Maximum Precipitation) was used for designing dam. From the concept, this study is applied the concept of monthly probable maximum precipitation for operating dam. It can be possible to let us know the appropriateness of a limiting water level at a rainy season. For the operation of dam at a dry season this study can predict roughly the flood season's pattern of precipitation by month or period, therfore the prediction of precipitation can rise efficient operation of a dam.

  • PDF

The Characteristics of Probable Maximum Flood on Wi Stream Watersheds (위천유역(渭川流域)의 가능최대홍수량(可能最大洪水量) 특성(特性))

  • Choi, Kyung-Sook;Suh, Seung-Duk
    • Current Research on Agriculture and Life Sciences
    • /
    • v.16
    • /
    • pp.37-44
    • /
    • 1998
  • The estimation of PMP (Probable Maximum Precipitation) and the analysis of characteristics of PMF (Probable Maximum Flood) according to the types of time distribution of rainfall and variations of base flow for the determination of design flood of major hydraulic structures in the watershed area of Wi stream were analysed. The PMP was estimated by the hydro-meteorological method suggested by the guideline of the World Meteorological Organization(WMO). The Blocking method was cited to transpose from PMP to PMS (Probable Maximum Storm) with time distribution. The unit hydrograph, applied for the estimation of PMF was derived by Clark's method. The summaryzed results : (1) The 72 hrs duration PMP in the area is 477.3mm which is 80mm less than the PMP map in Korea and 134 mm lager than the maximum precipitation of 342.9mm in Taegu, near the Wi stream watershed. (2) According to the types of time distribution and variations of base flow, the ranges of PMF for advanced type, central type and delayed type are 3,145.3~3,348.3cms, 3,774.6~3,977.7cms and 3,814.6~4,017.3cms, respectively. Those mean that peak discharge of advanced type is 600cms less than the central type and delayed type. (3) Delayed type among three types by Blocking method has been estimated the largest PMF of 4,017.3cms, and the advanced type has been estimated the smallest PMF of 3,145.3cms. The mean value of the peak PMF of 3,653.6cms may probably be resonable PMF in the Wi stream watershed. The mean PMF could probably be 1.7 times lager than the result of Gajiyama's equation. It is equivalent to the flood of return period 1,000 to 10,000 yrs.

  • PDF

A study on the Flood Frequency Analyzed in Consideration of Low Outliers. (Low Outliers를 고려한 홍수빈도분석에 관한 연구)

  • 이순혁;홍성표;박명근
    • Magazine of the Korean Society of Agricultural Engineers
    • /
    • v.30 no.4
    • /
    • pp.62-70
    • /
    • 1988
  • This study was conducted to solve the problems for the unsuitable parameters and the uncertainty of design flood can be appeared by low outliers were inclined to the lower part from the trend of the balance of the data. Derivation of reasonable design flood was attempted finally by modification of low outliers with analysis of flood frequency by means of Log Pearson Type Ill distribution. Three subwatersheds were selected as studying basins with the annual maximum series including low outliers along Geum River basin. The results through this study were analyzed and summarized as follows. 1. Log Pearson Type In distribution was confirmed as a reasonable one by X$^2$ goodness of fit test at Gong Ju, Gyu Am, og Cheon watershed along Geum River basin. 2. Probable flood flows for each watershed were derivated by flood frequency curve with outliers. 3. Weighted skew coefficient for each watershed was calculated for the evaluation of freq- uency factor which is needed for the modification of low outlier. 4. It was confirrned that adjusted frequency curve has a lower tendency than that of deletion of low outlier in common at all watersheds. 5. Final probable flood flows were derivated by modification with evaluation of modified basic statistics for three watersheds. 6. In comparison with a frequency curve with modification and one with outlier, The former has a higher probable flood flow within three years of return periods than that of the latter, and vice versa over three years of return periods.

  • PDF

Hydrological Stability Analysis of the Existing Soyanggang Multi-Purpose Dam (소양강 다목적댐의 수문학적 안정성 검토)

  • 고석구;신용노
    • Water for future
    • /
    • v.28 no.3
    • /
    • pp.187-195
    • /
    • 1995
  • This study aims at suggesting an alternative to improve current capacity of flood control for the existing Soyanggang multi-purpose dam which was constructed 20 years ago as a largest dam in Korea. The newly estimated value of the probable maximum precipitation(PMP) is 760.0 mm which is based on the hydrometeorological method. The peak inflow of 1000 years return period at the time of construction was 13,500$m^3$/s. However, the newly estimated peak inflow of the PMF is 18,100$m^3$/s which is 1.34 times bigger than the original one. In order to adopt the newly estimated PMF as a design flood, following four alternatives were compared; (1) allocation of more flood control space by lowering the normal high water level, (2) construction of a new spillway in addition to the existing one, (3) raising the existing dam crest, (4) construction of a new dam which has relevant flood control storage at the upstream of the Soyanggang multipurpose dam. The preliminary evaluation of these alternatives resulted in that the second alternative is most economical and feasible. So as to stably cope with the newly estimated PMF by meeting all the current functions of the multi-purpose dam, a detailed study of an additional spillway tunnel has to be followed.

  • PDF

Analysis of Flood Control Capacity of Agricultural Reservoir Based on SSP Climate Change Scenario (SSP 기후변화 시나리오에 따른 농업용 저수지 홍수조절능력 분석)

  • Kim, Jihye;Kwak, Jihye;Hwang, Soonho;Jun, Sang Min;Lee, Sunghack;Lee, Jae Nam;Kang, Moon Seong
    • Journal of The Korean Society of Agricultural Engineers
    • /
    • v.63 no.5
    • /
    • pp.49-62
    • /
    • 2021
  • The objective of this study was to evaluate the flood control capacity of the agricultural reservoir based on state-of-the-art climate change scenario - SSP (Shared Socioeconomic Pathways). 18 agricultural reservoirs were selected as the study sites, and future rainfall data based on SSP scenario provided by CMIP6 (Coupled Model Intercomparison Project 6) was applied to analyze the impact of climate change. The frequency analysis module, the rainfall-runoff module, the reservoir operation module, and their linkage system were built and applied to simulate probable rainfall, maximum inflow, maximum outflow, and maximum water level of the reservoirs. And the maximum values were compared with the design values, such as design flood of reservoirs, design flood of direct downstream, and top of dam elevation, respectively. According to whether or not the maximum values exceed each design value, cases were divided into eight categories; I-O-H, I-O, I-H, I, O-H, O, H, X. Probable rainfall (200-yr frequency, 12-h duration) for observed data (1973~2020) was a maximum of 445.2 mm and increased to 619.1~1,359.7 mm in the future (2011~2100). For the present, 61.1% of the reservoirs corresponded to I-O, which means the reservoirs have sufficient capacity to discharge large inflow; however, there is a risk of overflowing downstream due to excessive outflow. For the future, six reservoirs (Idong, Baekgok, Yedang, Tapjung, Naju, Jangsung) were changed from I-O to I-O-H, which means inflow increases beyond the discharge capacity due to climate change, and there is a risk of collapse due to dam overflow.

Comparison of flood inundation simulation between one- and two-dimensional numerical models for an emergency action plan of agricultural reservoirs

  • Kim, Jae Young;Jung, Sung Ho;Yeon, Min Ho;Lee, Gi Ha;Lee, Dae Eop
    • Korean Journal of Agricultural Science
    • /
    • v.48 no.3
    • /
    • pp.515-526
    • /
    • 2021
  • The frequency of typhoons and torrential rainfalls has increased due to climate change, and the concurrent risk of breakage of dams and reservoirs has increased due to structural aging. To cope with the risk of dam breakage, a more accurate emergency action plan (EAP) must be established, and more advanced technology must be developed for the prediction of flooding. Hence, the present study proposes a method for establishing a more effective EAP by performing flood and inundation analyses using one- and two-dimensional models. The probable maximum flood (PMF) under the condition of probable maximum precipitation (PMP) was calculated for the target area, namely the Gyeong-cheon reservoir watershed. The breakage scenario of the Gyeong-cheon reservoir was then built up, and breakage simulations were conducted using the dam-break flood forecasting (DAMBRK) model. The results of the outflow analysis at the main locations were used as the basis for the one-dimensional (1D) and two-dimensional (2D) flood inundation analyses using the watershed modeling system (WMS) and the FLUvial Modeling ENgine (FLUMEN), respectively. The maximum inundation area between the Daehari-cheon confluence and the Naeseong-cheon location was compared for each model. The 1D flood inundation analysis gave an area of 21.3 km2, and the 2D flood inundation analysis gave an area of 21.9 km2. Although these results indicate an insignificant difference of 0.6 km2 in the inundation area between the two models, it should be noted that one of the main locations (namely, the Yonggung-myeon Administrative and Welfare Center) was not inundated in the 1D (WMS) model but inundated in the 2D (FLUMEN) model.

PMP Estimation and Its Application for the Design Flood Determination in River Basin (하천유역의 설계 홍수량 결정을 위한 P.M.P.의 산정 및 적용)

  • 이순탁;박정규
    • Water for future
    • /
    • v.19 no.1
    • /
    • pp.75-86
    • /
    • 1986
  • This study aims at the analysis and application of PMP(Probable Maximum Precipitation)for the determination of design flood in the river basin planning and design of major hydraulic structures. PMP was estimated by hydro-meterological method statistical method and envelope curve method. PMF(Probable Maximum Flood)was then estimated from this PMP by synthetic unit hydrograph method and chow method. From the comparison of three methods for PMP estimation of magnitude of PMP in order of statistical, hydro-metrological, envelope curve method. Among PMP results estimated by each method it is believed that the hydro-meteorological method gave the best proper value in comparison with historical maximum rainfall because of this method reflected upon all meterological factor. From the comparison of PMP with probable rainfall and flood, it was shown that estimated value by statistical method and hydro-metrological method were nearly equivalent to the value of return period 100 years and its value of envelope curve method was equivalent to return period 200 to 500 year. It was found that PMF estimated from would be more safe for the design of major hydraulic structures in the consideration.

  • PDF

Estimation of Probable Maximum Flood by Duration using Creager Method (Creager 기법을 이용한 지속시간별 가능최대홍수량 산정)

  • Kang, Boo-Sik;Ryu, Seung-Yeop
    • Journal of the Korean Society of Hazard Mitigation
    • /
    • v.11 no.1
    • /
    • pp.77-84
    • /
    • 2011
  • The methods of the rational formula and Kajiyama formula have been widely used for estimating the peak flood for design to all kind of hydraulic structure. However, there are many limitations and we have to apply these methods to ungauged basin. These methods require to calculate the Probable Maximum Precipitation (PMP) before determining the Probable Maximum Flood (PMF). Creager's method (Creager et al., 1945) is a kind of estimation of specipic flood and this method provided nonlinear equations based on relationship between the drainage area and PMF in order to calculate the PMF of multipurpose dams over medium-sized. But this method has not much applied in Korea. Creager's coefficient is not clear about its application because this method has never been applied to dams in Korea. Based on the PMP for rainfull-runoff models with the PMF of small and larger dams in this research, the range and standard of Creager's coefficients with parameters are proposed to apply basin areas in Korea.

Flood Frequency Analysis by the Box-Cox Transformation

  • 이순혁;조성갑;박명곤
    • Magazine of the Korean Society of Agricultural Engineers
    • /
    • v.32 no.E
    • /
    • pp.20-32
    • /
    • 1990
  • Abstract This study was conducted to pursue the normalization of frequency distribution by making an approach to the coefficient of skewness to nearly zero through the Box-Cox transformation, to get probable flood flows can be calculated by means of the transformation equation which has been derivated by Box-Cox transformation in the annual maximum series of the applied watersheds. It has been concluded that Box-Cox transfromation is proved to be more efficient than logarithmic, square root and SMEMAX transformation which is based on the trigonometric solution of a right triangle whose three verteces repesent the smallest, median and largest observed values of a population in making the coefficient of skewness nearer to zero. Consequently it is shown that probable flood flows according to the return period based on Box-Cox transformation are closer to the observed data as compared to other methods including SMEMAX transformation and fitted probability distributions such as the three parameter lognormal and the type I extremal distribution for the applied watersheds.

  • PDF