Decadal & Intra-Annual Wetland Dynamics in the Endorheic Basins of the Arid Andes

Despite the importance of wetlands to ecosystems in arid and endorheic basins, and concerns over lithium mining impacts, the current understanding of hydrologic processes controlling surface water dynamics remains limited to basin-scale water budgets that ignore complex relationships between hydrology and the land surface. We therefore investigate the driving factors of inundation variability of surface water bodies in the lithium-rich Andean Altiplano region with remotely-sensed data, and we compare fluctuations in vegetated area to variability in surface water associated with wetlands. Climate data analysis provides an opportunity to assess climate-driven sensitivity. Certain wetlands sustain inundation to a prolonged region-wide drought, though high-elevation wetlands exhibit more drought-coincident declines in inundation, while also having the highest post-drought rebounds. Though some wetlands exhibit sensitivity to precipitation, intra-annual precipitation sensitivity and decadal drought sensitivity are uncoupled from each other. Stability in vegetated area fluctuation adjacent to such wetlands, which indicates groundwater discharge, is significantly coincident with both intra-annual and decadal surface water dynamics where vegetation exists. Comparison among basin attributes suggests higher-elevation basins experience greater variability in surface water dynamics regardless of the existence of vegetated wetlands. Therefore, while both groundwater and surface water are closely coupled, higher elevations introduce variability in hydrologic pathways for surface water inflow. We present the first regional study of the Altiplano to define patterns in surface water dynamics. This study also provides a framework for assessing surface water with implications for resource extraction for the Andean Altiplano and other arid regions within the context of rapidly changing climate.