scholarly journals A spatial bootstrap technique for parameter estimation of rainfall annual maxima distribution

2013 ◽  
Vol 10 (9) ◽  
pp. 11755-11794 ◽  
Author(s):  
F. Uboldi ◽  
A. N. Sulis ◽  
C. Lussana ◽  
M. Cislaghi ◽  
M. Russo
Keyword(s):  
Extreme Event ◽  
Surrounding Area ◽  
Precipitation Time Series ◽  
Spatial Gradients ◽  
Estimated Parameters ◽  
Bootstrap Technique ◽  
Historical Series ◽  
Repeated Sampling ◽  
Raingauge Data ◽  
Station Point

Abstract. Estimation of extreme event distributions and depth-duration-frequency (DDF) curves is achieved at any target site by repeated sampling among all available raingauge data in the surrounding area. The estimate is computed over a gridded domain in Northern Italy, using precipitation time series from 1929 to 2011, including data from historical analog stations and from the present-day automatic observational network. The presented local regionalisation naturally overcomes traditional station-point methods, with their demand of long historical series and their sensitivity to very rare events occurring at very few stations, possibly causing unrealistic spatial gradients in DDF relations. At the same time, the presented approach allows for spatial dependence, necessary in a geographical domain such as Lombardy, complex for both its topography and its climatology. The bootstrap technique enables evaluating uncertainty maps for all estimated parameters and for rainfall depths at assigned return periods.

scholarly journals A spatial bootstrap technique for parameter estimation of rainfall annual maxima distribution

2014 ◽  
Vol 18 (3) ◽  
pp. 981-995 ◽  
Author(s):  
F. Uboldi ◽  
A. N. Sulis ◽  
C. Lussana ◽  
M. Cislaghi ◽  
M. Russo
Keyword(s):  
Extreme Event ◽  
Surrounding Area ◽  
Precipitation Time Series ◽  
Spatial Gradients ◽  
Estimated Parameters ◽  
Bootstrap Technique ◽  
Historical Series ◽  
Repeated Sampling ◽  
Raingauge Data ◽  
Station Point

Abstract. Estimation of extreme event distributions and depth-duration-frequency (DDF) curves is achieved at any target site by repeated sampling among all available raingauge data in the surrounding area. The estimate is computed over a gridded domain in Northern Italy, using precipitation time series from 1929 to 2011, including data from historical analog stations and from the present-day automatic observational network. The presented local regionalisation naturally overcomes traditional station-point methods, with their demand of long historical series and their sensitivity to very rare events occurring at very few stations, possibly causing unrealistic spatial gradients in DDF relations. At the same time, the presented approach allows for spatial dependence, necessary in a geographical domain such as Lombardy, complex for both its topography and its climatology. The bootstrap technique enables evaluating uncertainty maps for all estimated parameters and for rainfall depths at assigned return periods.

scholarly journals MÉTODOS ESTIMADORES DOS PARÂMETROS DA DISTRIBUIÇÃO DE GUMBEL E SUA INFLUÊNCIA EM ESTUDOS HIDROLÓGICOS DE PROJETO

Irriga ◽  
2005 ◽  
Vol 10 (4) ◽  
pp. 334-350 ◽  
Author(s):  
Carlos Rogério de Mello ◽  
Antônio Marciano da Silva
Keyword(s):  
Maximum Likelihood ◽  
Probability Distribution ◽  
Daily Rainfall ◽  
Rio Grande ◽  
Likelihood Method ◽  
Estimated Parameters ◽  
Historical Series ◽  
Distribution Parameters ◽  
Rainfall Runoff Model ◽  
Runoff Model

MÉTODOS ESTIMADORES DOS PARÂMETROS DA DISTRIBUIÇÃO DE GUMBEL E SUA INFLUÊNCIA EM ESTUDOS HIDROLÓGICOS DE PROJETO  Carlos Rogério de Mello; Antônio Marciano da SilvaLaboratório de Hidráulica, Departamento de Engenharia, Universidade Federal de Lavras, Lavras, MG, [email protected]  1 RESUMO             Este trabalho objetiva estudar os efeitos que o método de estimativa dos parâmetros da distribuição de Gumbel proporcionam na estimativa da equação de chuvas intensas aplicando-se um modelo chuva-vazão, a conseqüente influência no hidrograma de projeto. Trabalhou-se com 7 estações pluviométricas da região Alto Rio Grande, ajustando-se a distribuição Gumbel à série histórica de precipitação máxima diária anual, pelas metodologias da Máxima Verossimilhança e Momentos. Utilizando o método de desagregação de chuvas, estimaram-se as respectivas equações de chuvas intensas. Com o método CN-SCS foram gerados os hidrogramas de projeto para uma bacia hidrográfica hipotética. Por meio do teste de l2, foram feitas comparações entre os modelos ajustados pelas metodologias. Verificou-se que as séries históricas ajustadas por Máxima Verossimilhança produziram os menores valores de l2, concluindo sobre a sua maior precisão. No entanto, os efeitos na geração da equação de chuvas intensas e por conseqüência, no hidrograma de projeto, apresentaram variações que, em alguns casos, foram de magnitude considerável, e em outros, de menor relevância em termos práticos. UNITERMOS: equação de chuvas intensas, máxima verossimilhança, método dos momentos.  MELLO, C.R.de; SILVA, A. M. da. ESTIMATING METHODS OF GUMBEL PROBABILITY DISTRIBUTION PARAMETERS AND THEIR INFLUENCE ON DESIGN HYDROLOGIC STUDIES  2 ABSTRACT             This work aimed to evaluate the influence of parameter estimating methods of Gumbel probability distribution for adjustment of p-d-f rainfall equation and, through rainfall-runoff model, generation of design hydrograph. Maximum annual daily rainfall from seven (7) weather stations, belonging to Alto Rio Grande region, were used and Gumbel probability distribution was adjusted to its parameters, which were estimated by the methods of Maximum Likelihood and Moment. Qui-square statistical test was applied to evaluate the accuracy of both methods. Desegregation rainfall technique was applied to estimate the respective p-d-f rainfall equations. CN-SCS method was used, based on estimated p-d-f rainfall equations to generate the design hydrograph for a hypothetical watershed. Through qui-squared test, adjusted methods were compared using different methodologies. Historical series that were adjusted by estimated parameters of Maximum Likelihood were more accurate, based on slower qui-square. However, effects on p-d-f rainfall equations and design hydrograph showed considerable differences in any situations, but in others these variations had smaller relevance in practical situations. KEYWORDS: p-d-f rainfall equation, Maximum Likelihood, Method of Moments.

scholarly journals 20 May 2013 Moore, Oklahoma, Tornado: Damage Survey and Analysis

2014 ◽  
Vol 29 (5) ◽  
pp. 1229-1237 ◽  
Author(s):  
Donald Burgess ◽  
Kiel Ortega ◽  
Greg Stumpf ◽  
Gabe Garfield ◽  
Chris Karstens ◽  
...  
Keyword(s):  
Damage Assessment ◽  
Extreme Event ◽  
Surrounding Area ◽  
Private Companies ◽  
Damage Survey ◽  
Future Studies ◽  
Survey Team ◽  
Damage Indicators ◽  
Survey Results ◽  
Tornado Damage

Abstract The tornado that affected Moore, Oklahoma, and the surrounding area on 20 May 2013 was an extreme event. It traveled 23 km and damage was up to 1.7 km wide. The tornado killed 24 people, injured over 200 others, and damaged many structures. A team of surveyors from the Norman, Oklahoma, National Weather Center and two private companies performed a detailed survey (all objects/structures) of the tornado to provide better documentation than is normally done, in part to aid future studies of the event. The team began surveying tornado damage on the morning of 21 May and continued the survey process for the next several weeks. Extensive ground surveys were performed. The surveys were aided by use of high-resolution aerial and satellite imagery. The survey process utilized the enhanced Fujita (EF) scale and was facilitated by use of a National Weather Service (NWS) software package: the Damage Assessment Toolkit (DAT). The survey team defined a “well built” house that qualified for an EF5 rating. Survey results document 4253 objects damaged by the tornado, 4222 of them EF-scale damage indicators (DIs). Of the total DIs, about 50% were associated with EF0 ratings. Excluding EF0 damage, 38% were associated with EF1, 24% with EF2, 21% with EF3, 17% with EF4, and only 0.4% associated with EF5. For the strongest level of damage (EF5), only nine homes were found. Survey results are similar to other documented tornadoes, but the amount of EF1 damage is greater than in other cases. Also discussed is the use of non-DI objects that are damaged and ways in which to improve future surveys.

Extreme wave events attribution using ERA5 datasets for storm-surge studies in the northern Adriatic sea

2020 ◽  
Author(s):  
Federico Porcu ◽  
Leonardo Aragão ◽  
Margherita Aguzzi ◽  
Andrea Valentini ◽  
Sisay Debele ◽  
...  
Keyword(s):  
Storm Surge ◽  
Wave Height ◽  
Extreme Events ◽  
Significant Wave Height ◽  
Adriatic Sea ◽  
Extreme Event ◽  
Measured Data ◽  
Northern Adriatic Sea ◽  
Northern Adriatic ◽  
Historical Series

<p>Extreme hydro-meteorological events are often defined by the statistical analysis of some parameter that measures the strength of the event over a long enough time series. The parameter could refer to the intensity of the event in terms of energy or to the impact of the event on the environment. This attribution becomes even more relevant when used as reference for future climate projections, suggesting a possible increase in the number of extreme events considering the attribution applied to the past database. <br>In the literature concerning storm-surge, the use of significant wave height (Hs) percentiles to define thresholds of an extreme event is a common practice when dealing with sufficiently long datasets. Usually, this value ranges from 90th up to 99.5th trying to highlight about 3-6 Hs peaks per year. But, in fact, thresholds should provide a benchmark for how much a region can withstand an extreme event. The Italian coast of the northern Adriatic is recently increasing its sensitivity to such episodes, that threaten one of the most active touristic hub of Italy, the highly valuable Po Delta UNESCO Biosphere Reserve and city of Venice fragile structure. Recently in late 2019, a strong event hit Venice with high tides flooding the city's main monument, St. Mark's Basilica, for the 6th time in 1200 years, with levels very similar to the worst event in history in 1966. <br>Attempting to better understand the distribution of these extreme events throughout last decades and how reanalysis products can be useful for storm-surge studies, this paper presents a climatological comparison of significant wave height data extracted from ECMWF ERA5 against the entire historical series available to the Nausicaa wave buoy. This station, owned and managed by ARPAE, is located about 8 km offshore the Municipality of Cesenatico, where the seabed is about 10m, and since 2007 has been used to monitor and prevent sea level related events. In the last 12 years, at least 10 extreme events have been reported based on hourly measured data in Nausicaa and the damage observed along the coast, allowing the local authorities to define Hs thresholds as 1.5 m to significant events and 3.0 m for extreme events. However, analysing the measured data in this period, at least 26 events that exceeded the 3 m threshold were observed, representing the percentile 99.81th of the historical series, whereas only 10 storm-surge events resulted in damage to cities or environmental protection areas. When analysing Hs extracted from ERA5 at the nearest grid point to Nausicaa (~ 30 km) for the same 26 events, all events were correctly identified by reanalysis and represented with an averaged correlation of 0.96. For Hs series extracted from ERA5, values above 3 m reached the 99.83rd percentile for the same period from 2007 to 2018, and 99.84th when expanded to the last 30 years (since 1989), showing that, although quite restricted, the 99.8th percentile seems to be a good value for identifying extreme events of storm-surge in the northern Adriatic Sea.</p>

World Christianity, ‘World Religions’ and the Challenge of Insider Movements

2020 ◽  
Vol 26 (1) ◽  
pp. 84-103
Author(s):  
Christian J. Anderson
Keyword(s):  
Religious Studies ◽  
World Religion ◽  
World Religions ◽  
Historical Series ◽  
Enlightenment Project ◽  
World Christianity ◽  
Other World ◽  
Religious Systems ◽  
The One ◽  
Insider Movements

While studies in World Christianity have frequently referred to Christianity as a ‘world religion’, this article argues that such a category is problematic. Insider movements directly challenge the category, since they are movements of faith in Jesus that fall within another ‘world religion’ altogether – usually Islam or Hinduism. Rather than being an oddity of the mission frontier, insider movements expose ambiguities already present in World Christianity studies concerning the concept of ‘religion’ and how we understand the unity of the World Christian movement. The article first examines distortions that occur when religion is referred to on the one hand as localised practices which can be reoriented and taken up into World Christianity and, on the other hand, as ‘world religion’, where Christianity is sharply discontinuous with other world systems. Second, the article draws from the field of religious studies, where several writers have argued that the scholarly ‘world religion’ category originates from a European Enlightenment project whose modernist assumptions are now questionable. Third, the particular challenge of insider movements is expanded on – their use of non-Christian cultural-religious systems as spaces for Christ worship, and their redrawing of assumed Christian boundaries. Finally, the article sketches out two principles for understanding Christianity's unity in a way that takes into account the religious (1) as a historical series of cultural-religious transmissions and receptions of the Christian message, which emanates from margins like those being crossed by insider movements, and (2) as a religiously syncretic process of change that occurs with Christ as the prime authority.

Economic Impact of a PGA Tournament (McGladrey Classic) on Surrounding Area

2018 ◽  
Vol 9 (8) ◽  
pp. 713-723
Author(s):  
Dominique Halaby ◽  
◽  
Benjamin McKay ◽  
Kristen Ruhland
Keyword(s):  
Economic Impact ◽  
Research Team ◽  
Golf Club ◽  
Surrounding Area ◽  
Golf Tournament ◽  
Expenditure Data

This study estimated the economic impact of the 2013 McGladrey Classic Golf Tournament (since renamed the RSM Classic) on Glynn County, Georgia. It was held at the Sea Island Golf Club, Seaside Course on Sea Island, Georgia in early November (7th through the 10th). This tournament is one of the stops for the PGA TOUR. The direct impacts were generated from spending from out-of-town visitors. These visitors included spectators, volunteers, title sponsor guests and the staff of the broadcast partner. In order to estimate the total amount of spending related to this event, the research team administered a survey to both volunteers online, prior to the event, and to spectators in person at the event. Additional expenditure data for the Golf Channel staff and McGladrey guests was provided by the Davis Love Foundation, host of this tournament.

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