Soil Clay Content Mapping Using a Time Series of Landsat TM Data in Semi-Arid Lands

A study demonstrates that soil clay content can be effectively mapped using a time series of Landsat Thematic Mapper (TM) images, achieving reasonable accuracy (R² = 0.65, RMSE = 100 g/kg). This method offers a fine spatial resolution alternative to existing soil maps in semi-arid regions like the Kairouan plain in Tunisia, which are often insufficiently precise for water balance modeling or thematic mapping. Researchers analyzed relationships between textural indices from four Landsat TM images and topsoil clay content using 100 soil samples, producing a 30-meter resolution map that was further refined with cokriging to address gaps caused by vegetation. The resulting map aligns well with existing soil maps but shows notable differences when compared to TerraSAR-X radar-derived clay content, with in-situ observations supporting the Landsat TM approach's accuracy.

Shabou, M., Mougenot, B., Chabaane, Z., Walter, C., Boulet, G., Aissa, N., & Zribi, M. (2015). Soil Clay Content Mapping Using a Time Series of Landsat TM Data in Semi-Arid Lands. Remote Sensing, 7(5), 6059–6078. https://doi.org/10.3390/rs70506059