Changes in the frequency and severity of hydrological droughts over Ethiopia from 1960 to 2013

Handle URI:
http://hdl.handle.net/10754/617798
Title:
Changes in the frequency and severity of hydrological droughts over Ethiopia from 1960 to 2013
Authors:
El Kenawy, A. M.; McCabe, Matthew ( 0000-0002-1279-5272 ) ; Vicente-Serrano, S. M.; López-Moreno, J. I.; Robaa, S. M.
Abstract:
Here we present an analysis of drought occurrence and variability in Ethiopia, based on the monthly precipitation data from the Climate Research Unit (CRU-v3.22) over the period from 1960 to 2013. The drought events were characterized by means of the Standardized Precipitation Index (SPI) applied to precipitation data at a temporal scale of 12 months. At the national scale, the results reveal a statistically significant decrease in the severity of droughts over the 54-year period, a pattern that is mostly attributed to a statistically significant decrease in the frequency of high intensity drought episodes (i.e., extreme and very extreme droughts), compared to moderate droughts. To assess the general patterns of drought evolution, a principal component analysis (PCA) was applied to the SPI series. PCA results indicate a high spatial heterogeneity in the SPI variations over the investigated period, with ten different spatially well-defined regions identified. These PCA components accounted for 72.9% of the total variance of drought in the region. These regions also showed considerable differences in the temporal variability of drought, as most of the regions exhibited an increase in wetness conditions in recent decades. In contrast, the regions that receive less than 400 mm of annual precipitation showed a declining  trend, with the largest changes occurring over Afar region. Generally, the highly elevated regions over the central Ethiopian Highlands showed the weakest changes, compared to the lowlands. This study confirms the local character of drought evolution over Ethiopia, providing evidence for policy makers to adopt appropriate local policies to cope with the risks of drought. Over Ethiopia, the detailed spatial assessment of drought evolution is required for a better understanding of the possible impacts of recurrent drought on agriculture, food production, soil degradation, human settlements and migrations, as well as energy production and water resources management across Ethiopia.
KAUST Department:
Biological and Environmental Sciences and Engineering (BESE) Division
Citation:
Changes in the frequency and severity of hydrological droughts over Ethiopia from 1960 to 2013 2016, 42 (1):145 Cuadernos de Investigación Geográfica
Publisher:
Universidad de la Rioja
Journal:
Cuadernos de Investigación Geográfica
Issue Date:
27-Jun-2016
DOI:
10.18172/cig.2931
Type:
Article
ISSN:
1697-9540; 0211-6820
Sponsors:
Research reported in this publication was supported by the King Abdullah University of Science and Technology (KAUST), Saudi Arabia. We wish to thank the Climate Research Unit (CRU) at the University of East Angelia (UK) for providing their data.
Additional Links:
https://publicaciones.unirioja.es/ojs/index.php/cig/article/view/2931
Appears in Collections:
Articles

Full metadata record

DC FieldValue Language
dc.contributor.authorEl Kenawy, A. M.en
dc.contributor.authorMcCabe, Matthewen
dc.contributor.authorVicente-Serrano, S. M.en
dc.contributor.authorLópez-Moreno, J. I.en
dc.contributor.authorRobaa, S. M.en
dc.date.accessioned2016-08-01T10:35:57Z-
dc.date.available2016-08-01T10:35:57Z-
dc.date.issued2016-06-27-
dc.identifier.citationChanges in the frequency and severity of hydrological droughts over Ethiopia from 1960 to 2013 2016, 42 (1):145 Cuadernos de Investigación Geográficaen
dc.identifier.issn1697-9540-
dc.identifier.issn0211-6820-
dc.identifier.doi10.18172/cig.2931-
dc.identifier.urihttp://hdl.handle.net/10754/617798-
dc.description.abstractHere we present an analysis of drought occurrence and variability in Ethiopia, based on the monthly precipitation data from the Climate Research Unit (CRU-v3.22) over the period from 1960 to 2013. The drought events were characterized by means of the Standardized Precipitation Index (SPI) applied to precipitation data at a temporal scale of 12 months. At the national scale, the results reveal a statistically significant decrease in the severity of droughts over the 54-year period, a pattern that is mostly attributed to a statistically significant decrease in the frequency of high intensity drought episodes (i.e., extreme and very extreme droughts), compared to moderate droughts. To assess the general patterns of drought evolution, a principal component analysis (PCA) was applied to the SPI series. PCA results indicate a high spatial heterogeneity in the SPI variations over the investigated period, with ten different spatially well-defined regions identified. These PCA components accounted for 72.9% of the total variance of drought in the region. These regions also showed considerable differences in the temporal variability of drought, as most of the regions exhibited an increase in wetness conditions in recent decades. In contrast, the regions that receive less than 400 mm of annual precipitation showed a declining  trend, with the largest changes occurring over Afar region. Generally, the highly elevated regions over the central Ethiopian Highlands showed the weakest changes, compared to the lowlands. This study confirms the local character of drought evolution over Ethiopia, providing evidence for policy makers to adopt appropriate local policies to cope with the risks of drought. Over Ethiopia, the detailed spatial assessment of drought evolution is required for a better understanding of the possible impacts of recurrent drought on agriculture, food production, soil degradation, human settlements and migrations, as well as energy production and water resources management across Ethiopia.en
dc.description.sponsorshipResearch reported in this publication was supported by the King Abdullah University of Science and Technology (KAUST), Saudi Arabia. We wish to thank the Climate Research Unit (CRU) at the University of East Angelia (UK) for providing their data.en
dc.language.isoenen
dc.publisherUniversidad de la Riojaen
dc.relation.urlhttps://publicaciones.unirioja.es/ojs/index.php/cig/article/view/2931en
dc.rightsArchived with thanks to Cuadernos de Investigación Geográfica. First published in Cuadernos de Investigación Geográfica in Vol 42, No 1(2016), published by Universidad de La Rioja (Spain).Set phrase to accompany link to published version: The original publication is available at: https://publicaciones.unirioja.es/ojs/index.php/cig/article/view/2931en
dc.subjectDroughten
dc.subjectStandardized Precipitation Indexen
dc.subjectPrecipitationen
dc.subjectVariabilityen
dc.subjectTrendsen
dc.subjectPrincipal Component Analysisen
dc.subjectEthiopiaen
dc.titleChanges in the frequency and severity of hydrological droughts over Ethiopia from 1960 to 2013en
dc.typeArticleen
dc.contributor.departmentBiological and Environmental Sciences and Engineering (BESE) Divisionen
dc.identifier.journalCuadernos de Investigación Geográficaen
dc.eprint.versionPublisher's Version/PDFen
dc.contributor.institutionDepartment of Geography, Mansoura University, Mansoura, Egypten
dc.contributor.institutionInstituto Pirenaico de Ecologia, Spanish National Research Council (IPE-CSIC), Spainen
dc.contributor.institutionDepartment of Astronomy, Space Science and Meteorology, Faculty of Science-Cairo University, Egypten
dc.contributor.affiliationKing Abdullah University of Science and Technology (KAUST)en
kaust.authorMcCabe, Matthewen
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