An Analysis of Precipitation Extreme Events Based on the SPI and EDI Values in the Free State Province, South Africa

Recognizing that, over the last several years, extreme rainfall has led to hazardous stress in humans, animals, plants, and even infrastructure, in the present study, we aimed to investigate the characteristics of droughts over the Free State (FS) Province of South Africa in order to determine the f...

Descripción completa

Guardado en:

Detalles Bibliográficos
Autores principales:	Omolola M. Adeola, Muthoni Masinde, Joel O. Botai, Abiodun M. Adeola, Christina M. Botai
Formato:	article
Lenguaje:	EN
Publicado:	MDPI AG 2021
Materias:	drought extreme frequency duration drought indices EDI Hydraulic engineering TC1-978 Water supply for domestic and industrial purposes TD201-500
Acceso en línea:	https://doaj.org/article/524097fb7ad54824970092384a7730e5
Etiquetas:	Agregar Etiqueta Sin Etiquetas, Sea el primero en etiquetar este registro!

id	oai:doaj.org-article:524097fb7ad54824970092384a7730e5
record_format	dspace
spelling	oai:doaj.org-article:524097fb7ad54824970092384a7730e52021-11-11T19:56:02ZAn Analysis of Precipitation Extreme Events Based on the SPI and EDI Values in the Free State Province, South Africa10.3390/w132130582073-4441https://doaj.org/article/524097fb7ad54824970092384a7730e52021-11-01T00:00:00Zhttps://www.mdpi.com/2073-4441/13/21/3058https://doaj.org/toc/2073-4441Recognizing that, over the last several years, extreme rainfall has led to hazardous stress in humans, animals, plants, and even infrastructure, in the present study, we aimed to investigate the characteristics of droughts over the Free State (FS) Province of South Africa in order to determine the future likelihood of reoccurrences of precipitation extremes using the generalized extreme value distribution (GEV) and extreme frequency analysis (EFA). In this regard, daily rainfall datasets from nine South African weather service homogenous climatic districts, spanning from 1980 to 2019, were used to compute: (a) the total annual rainfall, (b) the Effective Drought Index (EDI), and (c) the Standard Precipitation Index (SPI). The SPI was calculated for 3, 6, and 12 month accumulation periods (hereafter SPI-3, SPI-6, and SPI-12, respectively). The trend analysis results of the EDI and SPI-3, -6, and -12 showed that the Free State Province is generally negative, illustrating persistent drought. An analysis of the GEV parameters across the EDI and SPI-3, -6, and -12 values illustrated that the location, scale, and shape parameters exhibited a noticeable spatial variability across the Free State Province with the location parameter largely negative, the scale parameter largely positive, while the shape parameter pointed to an inherent Type III (Weibull) GEV distribution. In addition, the return levels for the drought/wet duration and severity of the EDI and SPI-3, -6, and -12 values generally showed increasing patterns across the corresponding return periods; the spatial contrasts were only noticeable in the return levels derived from the wet/drought duration and severity derived from SPI-3, -6, and -12 values (and not in the EDI). Further, the EFA results pointed to a noticeable spatial contrast in the return periods derived from the EDI and SPI-3, -6, and -12 values for each of the extreme precipitation categories: moderately wet, severely wet, extremely wet to moderately dry, and severely dry. Over four decades, the FS Province has generally experienced a suite of extreme precipitation categories ranging from moderately wet, severely wet, extremely wet to moderately dry, severely dry, and extremely dry conditions. Overall, the present study contributes towards implementation of effective drought early warning systems and can be used to enhance drought related policy and decision making in support of water resource management and planning in the FS Province.Omolola M. AdeolaMuthoni MasindeJoel O. BotaiAbiodun M. AdeolaChristina M. BotaiMDPI AGarticledroughtextremefrequencydurationdrought indicesEDIHydraulic engineeringTC1-978Water supply for domestic and industrial purposesTD201-500ENWater, Vol 13, Iss 3058, p 3058 (2021)
institution	DOAJ
collection	DOAJ
language	EN
topic	drought extreme frequency duration drought indices EDI Hydraulic engineering TC1-978 Water supply for domestic and industrial purposes TD201-500
spellingShingle	drought extreme frequency duration drought indices EDI Hydraulic engineering TC1-978 Water supply for domestic and industrial purposes TD201-500 Omolola M. Adeola Muthoni Masinde Joel O. Botai Abiodun M. Adeola Christina M. Botai An Analysis of Precipitation Extreme Events Based on the SPI and EDI Values in the Free State Province, South Africa
description	Recognizing that, over the last several years, extreme rainfall has led to hazardous stress in humans, animals, plants, and even infrastructure, in the present study, we aimed to investigate the characteristics of droughts over the Free State (FS) Province of South Africa in order to determine the future likelihood of reoccurrences of precipitation extremes using the generalized extreme value distribution (GEV) and extreme frequency analysis (EFA). In this regard, daily rainfall datasets from nine South African weather service homogenous climatic districts, spanning from 1980 to 2019, were used to compute: (a) the total annual rainfall, (b) the Effective Drought Index (EDI), and (c) the Standard Precipitation Index (SPI). The SPI was calculated for 3, 6, and 12 month accumulation periods (hereafter SPI-3, SPI-6, and SPI-12, respectively). The trend analysis results of the EDI and SPI-3, -6, and -12 showed that the Free State Province is generally negative, illustrating persistent drought. An analysis of the GEV parameters across the EDI and SPI-3, -6, and -12 values illustrated that the location, scale, and shape parameters exhibited a noticeable spatial variability across the Free State Province with the location parameter largely negative, the scale parameter largely positive, while the shape parameter pointed to an inherent Type III (Weibull) GEV distribution. In addition, the return levels for the drought/wet duration and severity of the EDI and SPI-3, -6, and -12 values generally showed increasing patterns across the corresponding return periods; the spatial contrasts were only noticeable in the return levels derived from the wet/drought duration and severity derived from SPI-3, -6, and -12 values (and not in the EDI). Further, the EFA results pointed to a noticeable spatial contrast in the return periods derived from the EDI and SPI-3, -6, and -12 values for each of the extreme precipitation categories: moderately wet, severely wet, extremely wet to moderately dry, and severely dry. Over four decades, the FS Province has generally experienced a suite of extreme precipitation categories ranging from moderately wet, severely wet, extremely wet to moderately dry, severely dry, and extremely dry conditions. Overall, the present study contributes towards implementation of effective drought early warning systems and can be used to enhance drought related policy and decision making in support of water resource management and planning in the FS Province.
format	article
author	Omolola M. Adeola Muthoni Masinde Joel O. Botai Abiodun M. Adeola Christina M. Botai
author_facet	Omolola M. Adeola Muthoni Masinde Joel O. Botai Abiodun M. Adeola Christina M. Botai
author_sort	Omolola M. Adeola
title	An Analysis of Precipitation Extreme Events Based on the SPI and EDI Values in the Free State Province, South Africa
title_short	An Analysis of Precipitation Extreme Events Based on the SPI and EDI Values in the Free State Province, South Africa
title_full	An Analysis of Precipitation Extreme Events Based on the SPI and EDI Values in the Free State Province, South Africa
title_fullStr	An Analysis of Precipitation Extreme Events Based on the SPI and EDI Values in the Free State Province, South Africa
title_full_unstemmed	An Analysis of Precipitation Extreme Events Based on the SPI and EDI Values in the Free State Province, South Africa
title_sort	analysis of precipitation extreme events based on the spi and edi values in the free state province, south africa
publisher	MDPI AG
publishDate	2021
url	https://doaj.org/article/524097fb7ad54824970092384a7730e5
work_keys_str_mv	AT omololamadeola ananalysisofprecipitationextremeeventsbasedonthespiandedivaluesinthefreestateprovincesouthafrica AT muthonimasinde ananalysisofprecipitationextremeeventsbasedonthespiandedivaluesinthefreestateprovincesouthafrica AT joelobotai ananalysisofprecipitationextremeeventsbasedonthespiandedivaluesinthefreestateprovincesouthafrica AT abiodunmadeola ananalysisofprecipitationextremeeventsbasedonthespiandedivaluesinthefreestateprovincesouthafrica AT christinambotai ananalysisofprecipitationextremeeventsbasedonthespiandedivaluesinthefreestateprovincesouthafrica AT omololamadeola analysisofprecipitationextremeeventsbasedonthespiandedivaluesinthefreestateprovincesouthafrica AT muthonimasinde analysisofprecipitationextremeeventsbasedonthespiandedivaluesinthefreestateprovincesouthafrica AT joelobotai analysisofprecipitationextremeeventsbasedonthespiandedivaluesinthefreestateprovincesouthafrica AT abiodunmadeola analysisofprecipitationextremeeventsbasedonthespiandedivaluesinthefreestateprovincesouthafrica AT christinambotai analysisofprecipitationextremeeventsbasedonthespiandedivaluesinthefreestateprovincesouthafrica
_version_	1718431346741739520

An Analysis of Precipitation Extreme Events Based on the SPI and EDI Values in the Free State Province, South Africa

Ejemplares similares