Towards a global map of historically degraded areas: S-world

The research community increasingly uses models to analyze global environmental problems. On soil degradation, these studies require high resolution, spatially exhaustive, quantitative data on soil properties. This study aimed to develop a methodology that takes stock of available legacy data to create a suitable global soil database to support integrated environmental assessments and future projections. Complex soil mapping units are first disaggregated using standardized toposequences to generate soil units described by a single soil type. Subsequently, ranges of soil properties per soil type were assessed using soil profile data. A simple model determines the soil property values within these ranges at a particular location based on landscape properties and human land use. Finally, the global distribution of the soil properties was determined. The methodology, denominated S-world (Soils of the World), resulted in readily available, high resolution, global soil property maps on the current as well as on the natural (undisturbed) state. The difference between the current and natural state is a first estimation of the soil property loss due to human interventions.