Natural and anthropogenic drivers of the 2016 drying of Lake Poopó, Bolivia

Abstract:

The central Andean highlands are a hotspot of climate variability, putting severe pressure on the water security and sustainable development of local populations. In Bolivian region of Oruro, the endorheic Lake Poopó, supports fishermen livelihoods and hosts a unique biodiversity. The water level in Poopó has been reducing considerably over the last decades, which culminated in its entire drying in January 2016. Here we analyse and attribute the relative contributions of various drivers to the drying process using a hydrological model of the catchment over the last several decades. We find that a substantial increase in irrigated area over the past two decades is the main cause of the 2016 event with a substantial expansion of the irrigated area in the basin between 2005 and 2010 alone. We also find that industrial and domestic surface water use have a very negligible impact on lake inflows, with an average flow reduction of less than 0.1%. We validate our results using MODIS satellite imagery of the lake.