Dunes and dunefields in the Bolivian Chaco as potential records of environmental change

摘要: Abstract Eastern Bolivia is situated along the southern margin of Amazon basin where climate characterized by strong hydroclimatic seasonality and high wind speeds related to South American Low Level Jet (SALLJ). In this setting, paper explores geomorphology environmental significance aeolian record in Bolivian Chaco. Based on analysis remote sensing imagery, 10 dunefields were mapped. Their size, topography geomorphic setting reflect long-term interactions with fluvial system Andean foreland. Preserved morphology includes different types linear sand streaks ridges, parabolic elongate morphologies, source-bordering dunes, sandsheets, transverse dunes and/or mega-ripples. This detailed local regional-scale dataset thus provides necessary base for establishment a chronological framework dune activity versus stability, mapping results spatial temporal variations processes their controls such as wind, vegetation, sediment supply. Compared extensive area covered inactive features, localized modern implies that conditions more conducive expansion during some periods late Quaternary, while predominance forms reflects variable but persisting control vegetation formation