Monitoring salt playa dynamics using Thematic Mapper data

Various image analysis techniques have been applied to multitemporal Landsat Thematic Mapper data collected over a four-year period. The results have been used to monitor sediment transport processes in semi-arid south central Tunisia. Process-domains on salt playas in the study area have been identified and mapped. Seasonal, interseasonal, and spatial changes on these playas have been related to sediment, salt, and moisture regimes. Surface water and groundwater activity, and eolian processes, are identified as important sediment, transport processes. The observations bring into question the traditional groundwater-based model of salt playa geochemistry; a revised set of integrated geochemical/geomorphological models is invoked.