Digital soil mapping

Digital soil mapping (DSM),as one of the sub-disciplines of soil science, was first introduced in McBratny et al. in 2003. It has since then witnessed many developments and has had a lot of scientific contributions at the global level. DSM aims to create and populate spatial soil information collected through field and laboratory observations that are coupled through quantitative relationships with environmental data. The output involves raster maps of predictions and uncertainties. The enhanced availability of spatial data, such as digital elevation models and satellite images; the increasing computation power to process data; the development of data-mining tools and GIS; and increasing global demand for spatial data including uncertainty assessments are some of the factors that have led to the success of field.This paper reviews the development of digital soil mapping through time, the covariates, some modeling examples,and the DSM studies so far carried out in Iran.