Environmental Covariate Data for the Disaggregation of the Reconnaissance Soil Map of the Busia Area, Kenya

<p>How can soil classes within a soil map unit be disaggregated? To answer this question, a soil landscape-rule based approach was used to disaggregate the soil map units by exploiting information in the map legend and the map unit descriptions. The descriptions often contain the mental soil landscape models used by the original soil surveyor(s) and were extracted from both the Busia soil survey report and soil class descriptions from the legend of the Soil Map of the World (FAO/UNESCO, 1974) and quantified by a set of rules. Second, a digital model must be developed that represents the landscape and environmental conditions of the original landscape. Environmental conditions of the study area were captured using six terrain attributes derived from a 30 m digital elevation model (DEM) in SAGA-GIS and parent material map extracted from the soil polygon map were used. Third, the rules that describe the locations of the different soil classes in the landscape must be applied to the digital model to place the soil classes in their most likely position(s) in the landscape.</p>

<p>FAO-UNESCO. (1974). Soil Map of the World, 1:5,000,000. Vol. 1: Legend. UNESCO, Paris, France.</p>