Using remote sensing data for monitoring rock glacier distribution in the Bolivian Andes : implications for water supply

Abstract

Many large cities in the South American Andes are located above 2500m and rely almost entirely on high-altitude water stocks (e.g. glaciers, lakes and rock glaciers). It is now evident that warming in the tropical Andes due to climate change has had a measurable impact on ice glaciers, which are known to have receded over the past decades, affecting water supply. This research is focused on rock glaciers in the Bolivian Andes as their contribution to mountain water supplies is ambiguous and understudied. Remote sensing approaches offer an efficient method for developing an inventory of the current rock glaciers in Bolivia. Rock glacier inventories elsewhere in the world have successfully utilised remote sensing data for this purpose (e.g. aerial photos, satellite images). In this research, we exploit a range of remote sensing data sources including historic air photos, fine spatial resolution satellite data (IKONOS 5 m resolution), global-extent DEMs (e.g. ASTER 30 m) and Google Earth. Fieldwork conducted in June 2011 provided the basis for field validation of the remote sensing approach, and targeted rock glaciers visited in July 2012 provided a basis for in situ measurement and thus validation of the remote sensing datasets. These data will be used to establish a detailed spatial understanding of rock glacier physical characteristics, and when coupled with the remote sensing data will enable potential water supply questions to be answered.