Spatial characterization of soil properties by digital soil mapping – examples from the Carpathian Basin
The aim of soil mapping is to explore and visualize the spatial extension and variability of the thematic knowledge on soils. Soil maps are thematic maps, which can present information on the primary or derivative soil characteristics, soil classes and knowledge about the processes, function and services of soils. The method for obtaining information on soils is sampling which results only point data and should be spatially extended by properly chosen methods.
Digital soil mapping (DSM) integrates the soil-related, environmental information with geostatistical and datamining methods within GIS environment. Modelling the soil-landscape relation enables the recognition of spatial variability of soil forming factors – like topography, climate, lithology or vegetation–, which determines the target soil properties. For the spatial extension of point related information, the DSM methods need environmental auxiliary variables which are in direct or indirect relation with the target soil property and supply exhaustive coverage for the area of interest. Environmental variables can are generally derived from digital elevation models (DEM), land cover data and Earth Observation (EO).
Based on DEM and its derivatives, topographical and geomorphological information can be obtained, which are in relation with the lithological, relief and run-off properties of the target area. Remote sensing provides quantitative information about the bare soils and vegetation which is also an efficient indicator of various soil properties.
Our paper will present some example for the application of DSM methods and how the each selected environmental variables and geostatistical methods improves the mapping of target soil properties.