Inventory and management of Lebanese soils integrating the soil geographical database of Euro-Mediterranean countries

ABSTRACT

Land management and degradation are among central issues in the 21[St] century. Several international and local organizations deal with land vulnerability to desertification and have elaborated databases addressing soil information and thematic mapping. Among these are the Global and National Soil and Terrain Database [SOTER], the FAO dbase, the Georeferenced Soil Database for Europe. These procedures are workable at different scales. The FAO-dbase is a soil profile and laboratory database. The remaining methodologies are not strictly a cartographic tool but conceptual models with computerized structure of the data. But, while SOTER uses the available soil maps as support to build the database, the Soil Geographical database of Euro-Mediterranean Countries aims at preparing a geographic database by relegating the problem of the cartographic representation of data to a secondary position. Extremely variable landform, lithology, climate and vegetation cover characterize the east Mediterranean including Lebanon. From the coastal strip to the high mountains different soil types are spread like Fluvisols, Cambisols, Vertisols, Luvisols, Regosols, Leptosols, and Calcisols. To build the soil database integrating the Euro-Mediterranean methodology, additional information was gathered from old studies of Lebanese soils run between 1950 and 1975. To complement the missing soil information reflecting the great variability of soil association, substantial fieldwork was recently undertaken for soil description and sampling. As a result, a new soil map of Lebanon at 11 M. scale was produced. The soil units were mapped using the lithology-landform association as separation criteria for the identification of soil entities. Both dominant and small typological units were maintained to reflect soil diversity and the need for differential land management. Beside the geometric dataset, the semantic dataset contains information on soil geomorphology, main physical and physico-chemical characteristics including land use, management practices and related problems. In this paper the work implemented to build a small scale, but comprehensive, soil database for Lebanon is reviewed. The paper discusses the database suitability for the assessment of current agricultural and environmental practices in relation to climatic conditions and soil parameters. A detailed analysis of the state and impact of land degradation, potential of land resources in view of geomorphology, land capability, and land vulnerability to desertification is presented