Digital Soil Mapping at a National Scale: A Knowledge and GIS Based Approach to Improving Parent Material and Property Information

One of the fundamental parameters in the soil formation equation is that relating to the parent material from which the soils have been derived. Such information is typically derived from geological surveys and paper maps. However, an increasing propensity to directly produce digital geological maps and associated data bases means that a far greater range of information can be made available to assist the soil scientist in mapping and predicting soil characteristics. Such geo-information typically can include, detailed lithological parameters, geochemistry of soils and sediments, engineering parameters and remotely sensed information. In this paper we describe on-going work at the British Geological Survey in which we are actively developing a national digital parent material map and property data base at a scale of 1:50 000. The main aim in doing this is to support the development of national soil data sets at a similar scale by those responsible for soil survey in the UK. However, our experience to date suggests that an adoption of similar strategies in regions and countries with sparse, soil orientated, data infrastructures could be of considerable value. For example many countries have, or are receiving, aid in support of the development and licensing of mineral resources (i.e. Madagascar, Afghanistan and Mauritania) which include not only significant improvements in geological mapping and associated GIS infrastructure, but also remote sensing and geochemical survey.