HYDROLOGY AND SURFACE ENERGY BUDGET AT THE SALAR DE ATACAMA, CHILE

The Salar de Atacama, northern Chile is located in the one of the driest regions of the planet, the Atacama Desert. In spite of the hyper-aridity, the salar or salt lake displays a wide range of hydrologic environments. The salar represents the terminal discharge for ground and surface water, resulting in wetlands, spring areas and evaporite formations. In addition, the salar supports a fascinating ecosystem including flamingos, llamas and guanacos. In addition to the ecosystem uses, water and brines from the subsurface beneath the Salar de Atacama are used for mineral extraction, and an expanding tourist industry utilizes both surface and ground water.

In this talk, we present an overview of the hydrology of the Salar de Atacama and focus on the largest sink of water in the basin; evaporation from the salar surface. Quantification of the seasonal rates of evaporation are critical to development of water budget projections for the salar and to provide proper management of both mineral and ecosystem resources. While previous work has shown that evaporation from playas is controlled by both the depth to the saturated zone and the surface soils and/or salt crust, evaporation estimates are often based on very local scale measurements. These local scale measurements must then be up-scaled 6-7 orders of magnitude to encompass the large area of the discharging salar. To integrate at larger scales, field measurements of surface energy balance and CO2 flux are planned for the Chilean winter using eddy covariance methods capable of integrating evaporative flux over km-scale regions. These measurements, combined with remote sensing of the salar surface will be used to infer salar-scale estimates of seasonal evaporation and biogeochemical processes from this remote and hyper-arid region.