Selection of variables for the purpose of regionalization of Iran's precipitation climate using multivariate methods

Dinpashoh, Yagob; Ahmad, Fadzil; Moghaddam, Mohsen Esmaeilzadeh; Jahanbakhsh, S; Mirnia, Mir Kamal

doi:10.1016/j.jhydrol.2004.04.009

Cited by 166 publications

(91 citation statements)

References 35 publications

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“…The average annual relative humidity across South Korea is 68.5% and average monthly relative humidity varies from 61.3% in April to 81.3% in July. Relative humidity is considered to be an important attribute that can influence precipitation climates [49], and has been used for regionalization of precipitation [50]. The attributes used for multivariate analysis are as follows: Latitude (Lat), Longitude (Long), Elevation Above Sea Level (EL), Mean Daily Minimum Temperature (MDMT), Annual Evaporation (AE) and Mean Relative Humidity (MRH).…”

Section: Selected Attributesmentioning

confidence: 99%

Regionalization of Drought across South Korea Using Multivariate Methods

Azam

Park

Maeng

et al. 2017

Water

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Topographic and hydro-climatic features of South Korea are highly heterogeneous and able to influence the drought phenomena in the region. The complex topographical and hydro-climatic features of South Korea need a statistically accurate method to find homogeneous regions. Regionalization of drought in a bivariate framework has scarcely been applied in South Korea before. Hierarchical Classification on Principal Components (HCPC) algorithm together with Principal Component Analysis (PCA) method and cluster validation indices were investigated and used for the regionalization of drought across the South Korean region. Statistical homogeneity and discordancy of the region was tested on univariate and bivariate frameworks. HCPC indicate that South Korea should be divided into four regions which are closer to being homogeneous. Univariate and bivariate homogeneity and discordancy tests showed the significant difference in their results due to the inability of univariate homogeneity and discordancy measures to consider the joint behavior of duration and severity. Regionalization of drought for SPI time scale of 1, 3, 6, 12, and 24 months showed significant variation in discordancy and homogeneity of the region with the change in SPI time scale. The results of this study can be used as basic data required to establish a drought mitigation plan on regional scales.

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Section: Selected Attributesmentioning

confidence: 99%

Regionalization of Drought across South Korea Using Multivariate Methods

Azam

Park

Maeng

et al. 2017

Water

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“…The use of clustering techniques in spatial and temporal patterns in climatic and meteorological research increased in recent decades. For instance, Santos et al (2010) and Dinpashoh et al (2004) used an algorithm that combined clusters analysis and PCA for dividing the research region into climate subregions. Since time series of precipitation are dynamic, certain non-stationary or chaotic properties may be embedded in the data, requiring appropriate methods to extract the features of interest (Hsu and Li 2010).…”

Section: Introductionmentioning

confidence: 99%

Spatial and temporal characteristics of droughts in the Northeast China Transect

et al. 2014

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In this study, drought trends and change magnitudes of the Northeast China Transect (NECT) were analyzed using the Mann-Kendall test and Theil-Sen's slope estimator. Meteorological data from 20 meteorological stations of NECT region from 1957 to 2012 were used. Results demonstrated that five stations had significant negative trends in precipitation. The magnitudes of the significant negative trends at the 95 % confidence level varied from -2.41 ± 1.05 mm year -1 at Tonghe station to -1.11 ± 0.51 mm year -1 at Qianguoerluosi station. Analysis of the seasonal precipitation series showed a mix of negative and positive trends. Many stations also exhibited strong contrasting seasonal trends that counterbalanced one other at the yearly level. In addition, cluster analysis based on discrete wavelet transform (DWT) was applied to the standard precipitation index (SPI) series. Results revealed three different and spatially well-defined subregions (east, center and west regions of NECT). Due to the decrease in precipitation from the east to the west, land use varies from forest regions in the east, to agriculture in the center, to pastoral areas in the west. Characteristics of drought events for each representative station of different subregions are explored using temporal evolution of the SPI values. Results showed that severe or extreme droughts occurred in 2001, 2003 in Tonghe, 1980 in Tongliao and 2005 123Nat Hazards (2015) 76:601-614 DOI 10.1007/s11069-014-1507 has great potential for examining spatial coherence of regional drought, which was consistent with not only the precipitation spatial distribution but also the characteristics of land use in the study area. This study not only provides important information on drought variability in the NECT, but also provides useful information for improving water management strategies and planning agricultural practices.

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“…Ela tem sido bastante estudada em diferentes regiões do mundo como principal indicador de secas: Guiana (SHAW, 1987); Áustria (EHRENDORFER, 1987); USA (GUTTMAN et al 1993;ARNAUD et al, 2002); Sahel (GRAEF e HAIGIS, 2001); Iran (DINPASHOH et al, 2004); Brasil (SILVA, 2004).…”

Section: Introductionunclassified

“…As secas se constituem num sério problema para a sociedade humana e para os ecossistemas naturais (DINPASHOH et al, 2004). Nesse sentido, diferentes metodologias têm sido utilizadas para se analisar a variabilidade da precipitação pluvial.…”

Section: Introductionunclassified

Variabilidade do número de dias chuvosos no estado de Sergipe – SE

Ricardo¹,

Pereira²,

Freitas³

et al. 2011

PAeT

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ResumoEntre os múltiplos fatores que afetam as atividades humanas, principalmente a agrícola, o clima se destaca por sua decisiva influência nas variações apresentadas pelas irregularidades nos períodos secos e chuvosos em determinada região. Entre as variáveis que compõem o clima, principalmente para as culturas anuais, a chuva é a variável que mais condiciona o resultado da produção das culturas. Neste sentido, o objetivo do trabalho foi avaliar a variabilidade de dados pluviométricos no Estado de Sergipe, SE, por meio da elaboração de mapas de isolinhas dos valores médios do número de dias chuvosos, e dos coeficientes de variação (CVs) da precipitação pluvial e do número de dias chuvosos, para os períodos anual, seco e chuvoso. Neste trabalho foi utilizada a série histórica mensal dos totais de precipitação de 40 estações pluviométricas, com no mínimo de 30 anos de dados, contínuos e sem falhas. Verificou que os maiores valores do coeficiente de variação são associados aos menores valores de precipitação pluvial e ao número de dias chuvosos. A variabilidade da precipitação é menor nas regiões de períodos chuvosos em relação às de períodos secos.Palavras-chave: coeficiente de variação, dia chuvoso, períodos secos e chuvosos. Variabilidad en el número de días lluviosos en Sergipe -SE ResumenEntre los muchos factores que afectan las actividades humanas, especialmente la agricultura, el clima se caracteriza por su decisiva influencia en las variaciones presentadas por irregularidades en los periodos de sequía y de lluvias en una región determinada. Entre las variables que componen el clima, sobre todo para los cultivos anuales, la lluvia es la variable que más influye en el resultado de la producción de cultivos. En este sentido, el objetivo fue evaluar la variabilidad de los datos de precipitación en el estado de Sergipe, SE, a través de la elaboración de mapas de isolíneas de los valores promedios de lo numero de días lluviosos, y de los coeficientes de variación (CV) de las lluvias e del número de días de lluvia por períodos anuales, secos y lluviosos. En este trabajo se ha utilizado la serie histórica mensual de precipitación total de 40 estaciones pluviométricas, con al menos 30 años de datos, continuos y sin interrupciones. Se verificó que los más altos valores del coeficiente de variación están asociados con menores niveles de precipitación y el número de días de lluvia. La variabilidad de la precipitación es menor en las regiones de periodos lluviosos, en comparación con las de períodos de sequía.Palabras clave: coeficiente de variación, día lluvioso, los periodos de lluvia y seca.

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Selection of variables for the purpose of regionalization of Iran's precipitation climate using multivariate methods

Cited by 166 publications

References 35 publications

Regionalization of Drought across South Korea Using Multivariate Methods

Regionalization of Drought across South Korea Using Multivariate Methods

Spatial and temporal characteristics of droughts in the Northeast China Transect

Variabilidade do número de dias chuvosos no estado de Sergipe – SE

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