In order to study petroleum mulch effects on soil, and sand dune fixation, thermal, and reflective bands of Landsat thematic mapper TM and ETM data, and other sources of information including topographic maps, aerial photos, and field work were used. The methodology was comprised of: images processing, statistic analysis, and relationship between thermal and reflective data. The results from image processing show that the behaviour of the Landsat thermal data is completely different from reflective data. The results from colour composite images including thermal bands have shown the capability of thermal bands in reparability of mulched and non-mulched areas. It was generally concluded that selection of TM, ETM thermal band is an important step to evaluate the area covered with petroleum mulch. Ratio mulch index was introduced as a best band combination in order to imagine mulch decomposition.