Las recientes sequías en la cuenca amazónica peruana: Orígenes climáticos e impactos hidrológicos

Abstract

Este trabajo ofrece un panorama inicial de las características climáticas y los impactos hidrológicos afines durante las recientes sequías extremas (1995, 1998, 2005 y 2010) en el río Amazonas peruano. Para ello se empleó una base de datos in situ de caudales y precipitaciones. Las sequías generalmente se asocian a anomalías positivas de temperatura superficial del mar (TSM) en el Atlántico tropical norte, vientos alisios y This work provides an initial overview of climate features and their related hydrological impacts during the recent extreme droughts (1995, 1998, 2005 and 2010) in the Peruvian Amazon river, using comprehensive in situ discharge and rainfall datasets. The droughts are generally associated with positive SST anomalies in the tropical North Atlantic and weak trade winds and water vapor transport toward the western part of the Amazon basin, which in association with increased subsidence over central and southern part of the basin, it explains the lack of rainfall and very low discharge values. However, in 1998 toward the end of the 1997-98 El Niño event, the drought was more likely related to an anomalous divergence of water vapor in the western Amazon that is characteristic of a warm event in the Pacific. During the austral spring and winter of 2010, the most severe drought since the seventies has been registered in the Amazonas. Its intensity and duration, when compared to the 2005 drought, can be explained by the addition of an El Niño in the austral summer and a very warm episode in the Atlantic during the austral autumn and winter. The lack of water in 2010, compared to the one in 2005, was more severe in the southern tropical tributaries of Amazonas than in the northern ones.