• 제목/요약/키워드: Rainfall and Flood

검색결과 997건 처리시간 0.034초

지표홍수 빈도곡선의 개발에 의한 미 계측지점의 확률 홍수량 추정 (An Estimation of Flood Quantiles at Ungauged Locations by Index Flood Frequency Curves)

  • 윤용남;신창건;장수형
    • 한국수자원학회논문집
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    • 제38권1호
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    • pp.1-9
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    • 2005
  • 본 연구에서는 지표홍수 빈도곡선을 개발하여 미계측 지점에서의 확률 홍수량을 추정해 보았다. 홍수빈도 분석은 한강유역의 9개 지점에 대하여 연최대치 홍수량 자료를 이용하여 분석하였다. 홍수빈도 곡선을 작성한 후 각 지점별 연평균홍수량( $Q_{2.33}$)을 결정하였고, 각 지점별 재현기간에 따른 연평균 홍수량에 대한 비를 산정 후 평균하였다. 그 결과 재현기간별로 다른 홍수량비가 산정되었다. 연평균 홍수량과 유역의 지형인자와의 상관 분석을 통해 다중선형 회귀식을 도출하였다. 미계측 지점의 확률 홍수량은 그 지점의 유역면적과 하상경사를 이용하여 경험식에 의해 연평균 홍수량을 산정 한 후 재현기간에 따른 홍수량비를 곱하여 산정 할 수 있다. 본 연구의 검증을 위하여 하천정비 기본계획에 수록되어 있는 재현기간별 확률홍수량과 비교한 결과 유역면적 2,000k $m^2$ 이하의 유역에서는 유사한 값을 모의 할 수 있었다. 기존 강우-유출 해석을 기반으로 한 설계 홍수량 추정 방법에의 적용은 재평가되어야 한다. 왜냐하면, 수문자료와 강우-유출모형은 많은 불확실성이 내포하고 있기 때문이다.

Quantitative Flood Forecasting Using Remotely-Sensed Data and Neural Networks

  • Kim, Gwangseob
    • 한국수자원학회:학술대회논문집
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    • 한국수자원학회 2002년도 학술발표회 논문집(I)
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    • pp.43-50
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    • 2002
  • Accurate quantitative forecasting of rainfall for basins with a short response time is essential to predict streamflow and flash floods. Previously, neural networks were used to develop a Quantitative Precipitation Forecasting (QPF) model that highly improved forecasting skill at specific locations in Pennsylvania, using both Numerical Weather Prediction (NWP) output and rainfall and radiosonde data. The objective of this study was to improve an existing artificial neural network model and incorporate the evolving structure and frequency of intense weather systems in the mid-Atlantic region of the United States for improved flood forecasting. Besides using radiosonde and rainfall data, the model also used the satellite-derived characteristics of storm systems such as tropical cyclones, mesoscale convective complex systems and convective cloud clusters as input. The convective classification and tracking system (CCATS) was used to identify and quantify storm properties such as life time, area, eccentricity, and track. As in standard expert prediction systems, the fundamental structure of the neural network model was learned from the hydroclimatology of the relationships between weather system, rainfall production and streamflow response in the study area. The new Quantitative Flood Forecasting (QFF) model was applied to predict streamflow peaks with lead-times of 18 and 24 hours over a five year period in 4 watersheds on the leeward side of the Appalachian mountains in the mid-Atlantic region. Threat scores consistently above .6 and close to 0.8 ∼ 0.9 were obtained fur 18 hour lead-time forecasts, and skill scores of at least 4% and up to 6% were attained for the 24 hour lead-time forecasts. This work demonstrates that multisensor data cast into an expert information system such as neural networks, if built upon scientific understanding of regional hydrometeorology, can lead to significant gains in the forecast skill of extreme rainfall and associated floods. In particular, this study validates our hypothesis that accurate and extended flood forecast lead-times can be attained by taking into consideration the synoptic evolution of atmospheric conditions extracted from the analysis of large-area remotely sensed imagery While physically-based numerical weather prediction and river routing models cannot accurately depict complex natural non-linear processes, and thus have difficulty in simulating extreme events such as heavy rainfall and floods, data-driven approaches should be viewed as a strong alternative in operational hydrology. This is especially more pertinent at a time when the diversity of sensors in satellites and ground-based operational weather monitoring systems provide large volumes of data on a real-time basis.

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GIS를 이용한 한계유량과 GcIUH 매개변수간의 상관성분석에 관한 연구 (Study of Correlation Between Flash Flood and GcIUH Parameters using GIS)

  • 양인태;박건
    • 대한공간정보학회지
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    • 제21권4호
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    • pp.37-44
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    • 2013
  • 최근 기상 이변에 따라 단시간에 집중되는 돌발홍수에 의해 해마다 막대한 인적, 물적 피해를 입고 있다. 이러한 국지성호우에 의한 산지하천이나 미소하천에서 첨두유출량을 예측하기 위한 도구로서 GIS를 적용하고 있는 추세이다. 하지만 수문학적 접근이 주를 이루고 있으며 GIS를 이용한 지형분석으로의 접근은 매우 미비한 실정이다. 본 연구에서는 돌발홍수를 발생시키는 강우량을 GIS기법과 GcIUH의 모형을 연계하여 산정하였고, 유역별 GcIUH 매개변수를 추출하여 한계유량에 따른 GcIUH 매개변수간의 상관관계를 분석하였다.

관개저수지의 최적 홍수관리방안 (Optimal Flood Control System for Irrigation Reservoir)

  • 문종필;민진우;김영식;박승기;김태철
    • 한국농공학회:학술대회논문집
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    • 한국농공학회 1998년도 학술발표회 발표논문집
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    • pp.311-317
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    • 1998
  • Recently irrigation reservoir has been developed to perform multipurpose function. To get a maximum effect it requires to establish optimal management system for irrigation reservoir in drought and flood season. Especially we dealt with optimal flood control system for irrigation reservoir in this study. This system consists of real-time rainfall data via online system, real-time flood forecasted by SCS method in hourly basis, storage volume by water balance equation, optimal releasing discharge from the gate, the water level in right downstream, and calculation of innundated area, depth, and time using GIS, and amount of flood damages. If we consider the relation of these sub module reasonably, we can reach the optimal flood control to minimize flood damage

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Why More Flood Disasters are Occurring (New Zealand Examples & Solutions)

  • Smart, G.M.;Mckerchar, A.I.
    • 한국수자원학회:학술대회논문집
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    • 한국수자원학회 2008년도 학술발표회 논문집
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    • pp.33-39
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    • 2008
  • Most New Zealanders reside in coastal regions and four of the larger cities are situated on active floodplains. There have been many recent storm events with rainfall AEPs of 1/150 or rarer and there have been recent flood-related disasters. Insurance claim statistics indicate that the frequency of floods is increasing. Such statistics are alarming local government authorities, insurance companies and populations in low-lying areas. The underlying physical and hydrologic causes of the flood disasters are investigated. It is found that the present numbers of rare rainfall events are not unexpected and there does not appear to be any significant trend evident in the occurrence of river floods. What is revealed is that the river floods appear clustered in certain decades. The clusters do not occur at the same times in different parts of the county. Recently there have been more floods in the north of New Zealand which is where more of the population lives. Also, the increase in population has seen more houses built in locations prone to flooding. Thus the increase in flood-related insurance claims is attributed to more people getting in the way of floods, rather than an increase in the number of floods that have occurred.

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Flood Simulation of Upriver District Considering an Influence of Backwater

  • Um, Dae Yong;Song, Yong Hyun
    • 한국측량학회지
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    • 제30권6_2호
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    • pp.631-642
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    • 2012
  • This study aims to predict inundation and flood-stricken areas more accurately by simulating flood damage caused by reversible flow of rain water in the upper water system through precise 3D terrain model and backwater output. For the upstream of the South Han-River, precise 3D terrain model was established by using aerial LiDAR data and backwater by area was output by applying the storm events of 2002 including the history of flood damage. The 3D flood simulation was also performed by using GIS Tool and for occurrence of related rainfall events, inundation events of the upriver region of water system was analyzed. In addition, the results of flood simulation using backwater were verified by making the inundation damage map for the relevant area and comparing it with flood simulation's results. When comparing with the results of the flood simulation applying uniformly the gauging station's water surface elevation used for the existing flood simulation, it is found that the results of the flood simulation using backwater are close to the actual inundation damage status. Accordingly, the causes of flood occurred in downstream of water system and upstream that has different topographic characteristics could be investigated and applying the simulation with backwater is proved more proper in order to procure accuracy of the flood simulation for the upriver region.

극한수문사상의 모의를 위한 포아송 클러스터 강우생성모형의 적용성 평가 (Evaluation of the Applicability of the Poisson Cluster Rainfall Generation Model for Modeling Extreme Hydrological Events)

  • 김동균;권현한;황석환;김태웅
    • 대한토목학회논문집
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    • 제34권3호
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    • pp.773-784
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    • 2014
  • 본 연구는 우리나라의 극한강우와 극한홍수를 모의하기 위한 MBLRP 포아송 클러스터 강우생성모형의 적용성을 평가하였다. 국내 61개의 기상청 지상기상관측시스템의 강우량 관측지점에 대하여 고립입자 군집화 최적화(ISPSO) 기법을 적용하여 모형의 매개변수를 추정하고, 추정된 매개변수를 바탕으로 각 강우관측지점에서 100년치의 가상 강우시계열을 생성하였다. 생성된 강우시계열을 이용하여 확률강우량 및 확률홍수량을 산정하고 이 값들을 관측치에 근거하여 산정된 값들과 비교하였다. 비교 결과, 모형에 의한 확률강우량은 관측치보다 평균적으로 20~42% 작았으며, 강우의 재현기간이 증가할수록 과소산정되는 정도가 증가하였다. 확률홍수량의 경우, 모형에 의한 값이 관측치에 근거한 값보다 31%에서 50% 작았으며, 이 과소산정량은 홍수의 재현기간의 증가 및 유역의 불투수도의 증가와 함께 증가하였다.

레이더 정량강우와 연계한 홍수유출 및 범람해석 시스템 확립 II. Cokriging을 이용한 2차원 정량강우 산정 (Development of a Flood Runoff and Inundation Analysis System Associated With 2-D Rainfall Data Generated Using Radar II. 2-D Quantitative Rainfall Estimation Using Cokriging)

  • 최규현;한건연;김광섭;이창희
    • 한국수자원학회논문집
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    • 제39권4호
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    • pp.335-346
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    • 2006
  • 수문모형의 많은 입력자료 가운데 강우 관측자료가 모의결과에 가장 주요한 원인을 가진다. 과거부터 수문모형은 유역에서의 평균강우량 자료를 한 지점에서의 강우량 자료에 의존해 왔다. 그러나, 지점에서 측정된 강우량 자료를 유역을 대표하는 평균강우량 산정에 이용할 경우 부적절한 경우가 발생할 수 있으며, 특히 그 계측망이 조밀하지 못할 경우 더욱 그러하다. 레이더의 경우 보다 넓은 유역 전체를 관측하기 때문에 유역에서의 평균강우량을 제공함에 있어 좋은 관측장비라 할 수 있다. 레이더를 이용하여 강우를 관측할 경우 직접적인 강우관측이 아니기 때문에 QPE에서 몇몇 한계가 있을 수 있으나, 강우자료의 공간변화도에 대한 좋은 정보를 제공해 준다. 또한 지상의 강우관측소에서의 강우측정자료는 지점에서의 강우량에 대한 정확한 정보를 제공해 준다. 따라서, 본 연구의 목적은 지상의 강우관측소에서 관측된 강우량 자료와 레이더를 이용하여 관측된 자료, 즉 두 가지 관측자료를 Ordinary cokriging 보간을 이용하여 통합함으로써 개선된 강우량 추정방법을 개발한다.

농업생산기반정비사업 계획설계기준 배수편 개정 (Revision of Agricultural Drainage Design Standards)

  • 김경찬;김영화;송재도;정상옥
    • 한국관개배수논문집
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    • 제21권1호
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    • pp.32-44
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    • 2014
  • In Korea, global warming caused by the climate changes impacted on weather system with increase in frequency and intensity of precipitation, and the rainfall pattern changes significantly by regional groups. Furthermore, it is expected that the regional and annual fluctuation ranges of the rainfall in the future would be more severe. Nowadays, agricultural drainage system designed by the existing standard of 20-year return period and 2 days of fixation time cannot deal with the increment rainfall such as localized heavy rain and local torrential rainfalls. Therefore, it is required to reinforce the standard of the drainage system in order to reduce the agricultural flood damage brought by unusual weather. In addition, it is needed to improve the standard of agricultural drainage design in order to cultivate farm products in paddy fields as facility vegetable cultivation and up-land field crop have been damaged by the moisture injury and flooding. In order to prepare for the changes of rainfall pattern due to climate changes and improve the agricultural drainage design standards by the increase of cultivating farm products, the purpose of this study is to examine the impact of climate changes, the changes of relative design standard, and the analytic situation of agricultural flood damages, to consider the drainage design standard revision, and finally to prepare for enhanced agricultural drainage design standards.

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Rainfall Intensity Estimation with Cloud Type using Satellite Data

  • Jee, Joon-Bum;Lee, Kyu-Tae
    • 대한원격탐사학회:학술대회논문집
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    • 대한원격탐사학회 2006년도 Proceedings of ISRS 2006 PORSEC Volume II
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    • pp.660-663
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    • 2006
  • Rainfall estimation is important to weather forecast, flood control, hydrological plan. The empirical and statistical methods by measured data(surface rain gauge, rainfall radar, Satellite) is commonly used for rainfall estimation. In this study, the rainfall intensity for East Asia region was estimated using the empirical relationship between SSM/I data of DMSP satellite and brightness temperature of GEOS-9(10.7${\mu}m$) with cloud types(ISCCP and MSG classification). And the empirical formula for rainfall estimation was produced by PMM (Probability Matching Method).

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