El aluvión del 9 agosto 2015 en Alto Patache, región de Tarapacá, Desierto de Atacama 1

Abstract

During the 09 August 2015 (strong El Niño year) heavy rains fell in the coastal Atacama Desert, including our Research Station Atacama UC_Alto Patache (cordillera de la Costa, Tarapacá Region). In this study we provide a detailed analysis of the meteorology and hydrogeomorphic response to the 51,6 mm in 6 hours of rain recorded in Alto Patache. In our control basin (7.2 Ha) we estimated a maximum erosion of ~1070 m3, which were partially stored in the distal alluvial fan, where we quantified 637 m3 of material. We estimated a mean water discharge of 11 m3 s-1 at the lower basin. The comparison between the meteorological and morphostratigraphical data allows us to define three phases that best characterize the anatomy of the 9A: Initial, Peak and End. We conclude that Alto Patache embraces an overall geomorphic stability that is interrupted recurrently by debris flows linkable to ENSO variability.