scholarly journals Comparative Study of Regional Frequency Analysis and Traditional At-Site Hydrological Frequency Analysis

Water ◽  
2019 ◽  
Vol 11 (3) ◽  
pp. 486
Author(s):  
Mengrui Li ◽  
Xiaodong Li ◽  
Tianqi Ao
Keyword(s):  
Frequency Analysis ◽  
Return Period ◽  
Flood Control ◽  
Regional Frequency Analysis ◽  
Optimal Frequency ◽  
Frequency Curve ◽  
Design Values ◽  
Homogeneous Regions ◽  
Regional Frequency ◽  
Hydrological Frequency Analysis

Hydrological frequency analysis plays an indispensable role in the construction of national flood control projects. This study selects the stations with the smallest and largest discordances in the nine homogeneous regions of Sichuan Province as the representative stations, and results obtained by regional frequency analysis are compared with those obtained by traditional at-site hydrological frequency analysis. The results showed that the optimal frequency distribution of each representative station obtained by traditional at-site hydrological frequency analysis and the ones of corresponding homogeneous regions obtained by regional frequency analysis were not necessarily consistent, which was related to the site and homogeneous regions. At the same time, there were also differences between the fitting of the theoretical rainstorm frequency curve obtained by the two methods and the observation. In general, in each homogeneous region, the results obtained by regional frequency analysis and traditional at-site hydrological frequency analysis at the stations with the largest frequency analysis were quite different. The design values obtained by the two methods were also increasingly different with the increase of the return period. The study has specific reflections on the differences between regional frequency analysis and traditional at-site hydrological frequency analysis.

scholarly journals Region-of-influence approach to a frequency analysis of heavy precipitation in Slovakia

2008 ◽  
Vol 12 (3) ◽  
pp. 825-839 ◽  
Author(s):  
L. Gaál ◽  
J. Kyselý ◽  
J. Szolgay
Keyword(s):  
Frequency Analysis ◽  
Growth Curves ◽  
Heavy Precipitation ◽  
Regional Frequency Analysis ◽  
Design Values ◽  
Site Design ◽  
Specific Alternative ◽  
Method Yield ◽  
Regional Frequency ◽  
Selection Of

Abstract. The paper compares different approaches to regional frequency analysis with the main focus on the implementation of the region-of-influence (ROI) technique for the modelling of probabilities of heavy precipitation amounts in the area of the Western Carpathians. Unlike the conventional regional frequency analysis where the at-site design values are estimated within a fixed pooling group (region), the ROI approach as a specific alternative to focused pooling techniques makes use of flexible pooling groups, i.e. each target site has its own group of sufficiently similar sites. In this paper, various ROI pooling schemes are constructed as combinations of different alternatives of sites' similarity (pooling groups defined according to climatological characteristics and geographical proximity of sites, respectively) and pooled weighting factors. The performance of the ROI pooling schemes and statistical models of conventional (regional and at-site) frequency analysis is assessed by means of Monte Carlo simulation studies for precipitation annual maxima for the 1-day and 5-day durations in Slovakia. It is demonstrated that a) all the frequency models based on the ROI method yield estimates of growth curves that are superior to the standard regional and at-site estimates at most individual sites, and b) the selection of a suitable ROI pooling scheme should be adjusted to the dominant character of the formation of heavy precipitation.

scholarly journals Drought Analysis in East Nusa Tenggara (Indonesia) Using Regional Frequency Analysis

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Heri Kuswanto ◽  
Anggi Wahyu Puspa ◽  
Imam Safawi Ahmad ◽  
Fausania Hibatullah
Keyword(s):  
Frequency Analysis ◽  
Return Period ◽  
Extreme Drought ◽  
Regional Frequency Analysis ◽  
Drought Risk ◽  
Drought Analysis ◽  
Daily Precipitation Data ◽  
Pearson Type ◽  
Normal Rainfall ◽  
Regional Frequency

Drought is a condition of a shortage of water that has an impact on economic activity. This research studies the severe drought area in Indonesia using Regional Frequency Analysis (RFA), based on daily precipitation data recorded at nine stations. The analysis reveals five homogeneous regions, based on discordancy and heterogeneity tests. Furthermore, the L-moment approach is applied to investigate the regional distribution and suggests that the Pearson type III distribution is the distribution that best fits the five regions. This distribution is also used to calculate the regional growth curve that is employed in the drought analysis. The drought return period analysis, for conditions of 40% of normal rainfall, concludes that the region containing the Fransiskus Xaverius, Gewayantana, and Mali stations has the highest drought risk, indicated by the fastest return period estimate of 2 years and 4 months. Moreover, the extreme drought analysis shows that two of the regions have the potential to experience the return of extreme drought, with less than 20% of normal rainfall, in less than four years.

scholarly journals Regional Frequency Analysis of Precipitation Extremes and Its Spatio-Temporal Patterns in the Hanjiang River Basin, China

Atmosphere ◽  
2019 ◽  
Vol 10 (3) ◽  
pp. 130 ◽  
Author(s):  
Wenlong Hao ◽  
Zhenchun Hao ◽  
Feifei Yuan ◽  
Qin Ju ◽  
Jie Hao
Keyword(s):  
River Basin ◽  
Frequency Analysis ◽  
Return Period ◽  
Extreme Events ◽  
Extreme Precipitation ◽  
Precipitation Extremes ◽  
Regional Frequency Analysis ◽  
Hanjiang River ◽  
Spatio Temporal ◽  
Regional Frequency

Extreme events such as rainstorms and floods are likely to increase in frequency due to the influence of global warming, which is expected to put considerable pressure on water resources. This paper presents a regional frequency analysis of precipitation extremes and its spatio-temporal pattern characteristics based on well-known index-flood L-moments methods and the application of advanced statistical tests and spatial analysis techniques. The results indicate the following conclusions. First, during the period between 1969 and 2015, the annual precipitation extremes at Fengjie station show a decreasing trend, but the Wuhan station shows an increasing trend, and the other 24 stations have no significant trend at a 5% confidence level. Secondly, the Hanjiang River Basin can be categorized into three homogenous regions by hierarchical clustering analysis with the consideration of topography and mean precipitation in these areas. The GEV, GNO, GPA and P III distributions fit better for most of the basin and MARE values range from 3.19% to 6.41% demonstrating that the best-fit distributions for each homogenous region is adequate in predicting the quantiles estimates. Thirdly, quantile estimates are reliable enough when the return period is less than 100 years, however estimates for a higher return period (e.g., 1000 years) become unreliable. Further, the uncertainty of quantiles estimations is growing with the growing return periods and the estimates based on R95P series have a smaller uncertainty to describe the extreme precipitation in the Hanjiang river basin (HJRB). Furthermore, In the HJRB, most of the extreme precipitation events (more than 90%) occur during the rainy season between May and October, and more than 30% of these extreme events concentrate in July, which is mainly impacted by the sub-tropical monsoon climate. Finally, precipitation extremes are mainly concentrated in the areas of Du River, South River and Daba Mountain in region I and Tianmen, Wuhan and Zhongxiang stations in region III, located in the upstream of Danjiangkou Reservoir and Jianghan Plain respectively. There areas provide sufficient climate conditions (e.g., humidity and precipitation) responsible for the occurring floods and will increase the risk of natural hazards to these areas.

Extreme events Analysis of Short-Duration Rainfall and Intensity-Duration-Frequency curve using Scaling Model in North Korea

2020 ◽  
Author(s):  
Younghun Jung ◽  
Kyungwon Joo ◽  
JoonHak Lee ◽  
Jun-Haeng Heo
Keyword(s):  
Climate Change ◽  
Short Duration ◽  
Frequency Analysis ◽  
21St Century ◽  
North Korea ◽  
Flood Control ◽  
Extreme Rainfall ◽  
Regional Frequency Analysis ◽  
Index Flood ◽  
Regional Frequency

<p>Climate change has emerged as one of the defining issues of the early 21st century. Recent research confirms that the imprint of human induced climate change can be recognized in current accident events. There is a high probability of observed trends, such as increases in heat waves and heavy extreme rainfall events, intensifying over the 21st century. Extreme weather and climate events are anticipated to generate significant risks to societies and ecosystem. This paper focuses on estimation rainfall quantile using sclaling model for short duration IDF curve in North Korea. It is very important to manage the flood control facilities because of increasing the frequency and magnitude of severe rain storms. For managing flood control facilities in possibly hazardous regions, data sets such as elevation, gradient, channel, land use and soil data should be filed up. Using this information, the disaster situations can be simulated to secure evacuation routes for various rainfall scenarios. The aim of this study is to investigate and determine extreme rainfall quantile estimates in North Korea Cities using index flood method with L-moments parameter estimation. Regional frequency analysis trades space for time by using annual maximum rainfall data from nearby or similar sites to determine estimates for any given site in a homogeneous region. Regional frequency analysis based on pooled data is recommended for estimation of rainfall quantiles at sites with record lengths less than 5T, where T is return period of interest. Many variables relevant to precipitation can be used for grouping a region in regional frequency analysis. For regionalization of Han River basin, the k-means method is applied for grouping regions using variables of meteorology and geomorphology. The results from the k-means method are compared for each region using various probability distributions. In the final step of the regionalization analysis, goodness-of-fit measure is used to evaluate the accuracy of a set of candidate distributions. And rainfall quantiles by index flood method are obtained based on the appropriate distribution(GEV and GLO). Therefore, it could be possible to estimate rainfall quantiles using scale invariance and frequency analysis for Wonsan, Jangjeon, and Pyeonggang rainfall stations in North Korea. And then, rainfall quantiles based on various scenarios are used as input data for disaster simulations.</p><p>Acknowledgements</p><p>This work was supported by the National Research Foundation of Korea(NRF) grant funded by the Korea government(MSIT) (No. 2019R1A2C2010854).</p><p> </p>

scholarly journals ASSESSMENT OF THE REGIONAL FREQUENCY ANALYSIS TO THE ESTIMATION OF EXTREME STORM SURGES

2012 ◽  
Vol 1 (33) ◽  
pp. 27 ◽  
Author(s):  
Jérôme Weiss ◽  
Pietro Bernardara ◽  
Michel Benoit
Keyword(s):  
Frequency Analysis ◽  
Storm Surges ◽  
Regional Frequency Analysis ◽  
Dependence Structure ◽  
The North ◽  
Extreme Storm ◽  
Physically Based ◽  
Pairwise Dependence ◽  
Homogeneous Regions ◽  
Regional Frequency

Regional frequency analysis (RFA) is performed to estimate extreme storm surges along the French coasts of the Atlantic Ocean, the English Channel and the Southern part of the North Sea. An insight on the formation of physically homogeneous regions from a criterion of propagation of storms is provided. The treatment of the pairwise dependence structure within a given region through a spatial extreme value copula is also considered, leading to a model coupling physically-based RFA and spatial dependence to describe the probabilistic behavior of extreme storm surges.

scholarly journals Hybrid Approach to Delineation of Homogeneous Regions for Regional Precipitation Frequency Analysis

2009 ◽  
Vol 57 (4) ◽  
pp. 226-249 ◽  
Author(s):  
Ladislav Gaál ◽  
Ján Szolgay ◽  
Milan Lapin ◽  
Pavol Faško
Keyword(s):  
Distribution Function ◽  
Frequency Analysis ◽  
Regional Distribution ◽  
Hybrid Approach ◽  
Heavy Precipitation ◽  
Regional Frequency Analysis ◽  
Precipitation Frequency ◽  
Precipitation Analysis ◽  
Homogeneous Regions ◽  
Regional Frequency

Hybrid Approach to Delineation of Homogeneous Regions for Regional Precipitation Frequency AnalysisRegional frequency analysis of heavy precipitation amounts based on the estimation of the parameters of a regional distribution function usingL-moments is adopted for the specific geographical-climatological settings of Slovakia. The paper focuses on the first step of the regionalL-moment algorithm (Hosking, Wallis, 1997), which is the delineation of homogeneous regions. Objective and process-based logical pooling techniques are used to form homogeneous pooling groups of rainfall gauging stations for regional frequency analysis ofk-day precipitation amounts (k= 1 to 5 days). Even though the delineation of homo-geneous regions by means of objective methods is generally accepted and recommended in the literature, it is concluded here that such a pooling of similar sites should not be carried out automatically in precipitation analysis. Instead, a combination of physical/geomorphological considerations and objective methods should be preferred.

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