Multidecadal variability in hydro-climate of Okavango river system, southwest Africa, in the past and under future climate

Wolski, P, Todd, M C, Murray-Hudson, M A and Tadross, M (2012) Multidecadal variability in hydro-climate of Okavango river system, southwest Africa, in the past and under future climate. Journal of Hydrology, 475. pp. 294-305. ISSN 0022-1694

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Abstract

The focus of this paper is to understand the multi-decadal oscillatory component of variability in the Okavango River system, in southwestern Africa, and its potential evolution through the 21st century under climate change scenarios. Statistical analyses and hydrological modelling are used to show that the observed multi-decadal wet and dry phases in the Okavango River and Delta result from multi-decadal oscillations in rainfall, which are likely to be related to processes of internal variability in the climate system, rather than external natural or anthropogenic forcing. Analyses of changes in this aspect of variability under projected climate change scenarios are based on data from a multi-model ensemble of 19 General Circulation Models, which are used to drive hydrological models of the Okavango River and Delta. Projections for the 21st century indicate a progressive shift towards drier conditions attributed to the influence of increasing temperatures on water balance. It is, however, highly likely that multi-decadal oscillations, possibly of similar magnitude to that of 20th century, will be superimposed on the overall trend. These may periodically offset or amplify the mean drying trend. This effect should be accounted for in water and catchment management and climate change adaptation strategies.

Item Type: Article
Schools and Departments: School of Global Studies > Geography
Subjects: Q Science
Depositing User: Martin Todd
Date Deposited: 14 Mar 2013 09:04
Last Modified: 07 Mar 2017 08:19
URI: http://sro.sussex.ac.uk/id/eprint/41593

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