Threshold level approach for streamflow drought analysis in the Central Andes of Argentina: a climatological assessment |
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| Authors: | Juan A Rivera Diego C Araneo Olga C Penalba |
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| Institution: | 1. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales (CCT-Mendoza/CONICET), Mendoza, Argentina;2. Universidad Juan Agustín Maza, Guaymallén, Mendoza, Argentina;3. Departamento de Ciencias de la Atmósfera y los Océanos, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina;4. Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina |
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| Abstract: | A streamflow drought climatology was developed over the Central Andes of Argentina, a semi-arid region highly vulnerable to climatic variations, based on the analysis of daily historical streamflow records. A threshold level approach was applied on a daily basis for three different severity levels in order to depict the main characteristics of droughts – number of drought events, mean duration and mean severity – over the period 1957–2014. Based on three annual indices that summarize the frequency of drought events, their duration and severity, we identified the main regional dry periods and the main modes of variability through an empirical decomposition. These modes are linked to La Niña conditions on inter-annual time scales and the Pacific Decadal Oscillation for the decadal variations, showing the influence of the tropical Pacific Ocean in the development of streamflow drought conditions and its relevance for potential predictability of hydroclimatic variations over the region. |
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| Keywords: | streamflow drought climatology temporal variability Central Andes Argentina water resources |
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