MAPPING THE IRON-OXIDE CONTENT OF DUNE SANDS, NAMIB SAND SEA, NAMIBIA, USING LANDSAT THEMATIC MAPPER DATA

A linear mixture model was applied to Landsat Thematic Mapper data to map iron-oxide content over the northern part of the Namib Sand Sea, N amibia. Field samples were collected to calibrate the remotely sensed iron oxide proportions to dithionite extractable Fe in mg g(-1), the i n situ proportions correlating strongly with the remotely sensed estim ates (r=0.91). The results reveal a region of high Fe-oxide concentrat ion in the east, an area of low Fe-oxide concentration in the west, se parated by a mixing zone. We interpret this to indicate that there is more than one sand source contributing to the sand sea. (C) Elsevier S cience Inc., 1997.