DEVELOPMENT OF A SOIL GEOGRAPHIC DATABASE FROM THE SOIL MAP OF THE EUROPEAN COMMUNITIES

Questions on land use and soil conservation require increasingly accurate information on soil properties and their geographical location. Soil maps have helped to answer them thus helping in decision making. Information presented on soil maps are now managed by computer. This is the case for the Soil Map of European Communities (EC) at a scale of 1 : 1000000. Computerization of soil maps is often limited to soil boundaries and to the few descriptive items on the paper themselves. Much of the original survey is lost either during mapping or because it is published separately in explanatory notes or legends. This was also the case for the EC Soil Map. Many scientific publications and draft documents were used to make the original paper map, but were greatly condensed and simplified. The first version of the EC soil database is an exact copy of the paper map, thus having the same deficiencies. Using Geographical Information System technology, an efficient data structure has to be developed to take into account efficiently the internal organization of the soil cover. Such a structure should match conceptually the soil scientist review of spatial soil organization at a given scale within a computerized model. As a first step towards such a ''Soil Spatial Organization Model'' the material available for the compilation of the EC Soil Map is analysed. A logical data structure to receive a posteriori these informations is proposed and the database's improvement in terms of quantity as well as quality is demonstrated.