Summary
Spatial patterns of the precipitation variability over West Africa south of the Sahara and their changes during the past 52 (1921–1972) years are examined using eigenvector analysis of the mean annual precipitation totals. The time series of the coefficients of the extracted eigenvectors are used to identify intervals of change in the large scale distribution of annual precipitation totals. A tendency of drought reoccurrence in three, seven and thirty years periods can be indicated by “Maximum Entropy Spectral Analysis”.
Zusammenfassung
Die Raummuster der Niederschlagsvariabilität und ihre zeitlichen Änderungen im Ablauf der letzten 52 Jahre (1921–1972) werden für Westafrika südlich der Sahara mit Hilfe einer Hauptkomponentenanalyse der mittleren jährlichen Niederschlagssummen analysiert. Anhand der Zeitreihen der Koeffizienten zu den extrahierten Eigenvektoren werden die zeitlichen Änderungen der großräumigen Verteilungen der jährlichen Niederschlagssummen herausgearbeitet. Die Zeitreihen der Koeffizienten werden zudem einer “Maximum Entropy Spectrum Analyse” unterzogen. Eine Tendenz zum Auftreten regionaler Dürren kann im drei-, sieben- und dreißigjährigen Rhythmus belegt werden.
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Klaus, D. Spatial distribution and periodicity of mean annual precipitation south of the Sahara. Arch. Met. Geoph. Biokl. B. 26, 17–27 (1978). https://doi.org/10.1007/BF02266917
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DOI: https://doi.org/10.1007/BF02266917