GIS and Soil

Soil is a natural body consisting of layers (soil horizons) resulting from the interplay between climate, topography, organisms, parent material (underlying geologic bedrock), and time. Accurate soil data are needed in order to develop reliable and high-resolution soil maps for hydrological analysis, environmental protection, agriculture, and forest management. The several items of information required for soil characterization, deriving from sources with different spatial resolution, can be easily stored and managed within a geographic information system (GIS). Digital soil mapping (DSM) allows one to analyze the relationships between soil properties and ancillary data (e.g., topographic attributes and remote/proximal sensing data) through several pedometric techniques. The article represents an attempt to synthesize the use of GIS in soil sciences at different spatial scale by (i) describing the increasing availability of ancillary data for soil characterization; (ii) illustrating the main relationships between soil properties and digital elevation model-derived topographic features; (iii) summarizing spatial and nonspatial pedometric techniques for analyzing and modeling soil properties; (iv) illustrating some applications of GIS in soil science also highlighting the contribution of DSM for land use planning and soil protection.