Surface-sediment dynamics in a dust source from thermal infrared remote sensing

Characteristics of surface sediments are significant factors in modeling dust entrainment and wind erosion, and it is of interest to monitor them using remote sensing in source areas at high spatial and temporal resolution. A time-series of Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) data were acquired for Soda Playa (CA), a modern depositional environment associated with dust emission. Analysis of the multispectral thermal infrared (TIR) images indicates that the type and distribution of the surface sediments can be mapped by linear spectral unmixing techniques. Image-based spectral endmembers extracted from the ASTER five-band surface emissivity data were used to drive fraction images. The spectral-mixture analysis reveals that the mosaic-like pattern of the main sediment types - silica-rich, clay-rich, and salt-rich, changes in time as a consequence of interactions between hydrologic and geomorphic processes in the playa environment. The results highlight the dynamic response of the playa-surface to wind erosion, and suggest that this technique is useful for continuously detecting dust emission potential in sources characterized by a small extension and a complex surface.