Investigation and feasibility study of an irrigation project south of Lake Chad, Nigeria. Annex 1: soil survey and land classification. V. 1: Report. Feasibility report

aerial surveying alcalinidad alkalinity cartografia cartographie cartography classification des sols classification des terres fisiografia land classification land use methode methods pedogenese photointerpretation physiographie physiography reconocimiento de suelos salinidad salinity soil soil classification soil genesis soil morphological features soil surveys soil texture soil types sol suelo textura del suelo texture du sol tipos de suelos topografia topographie topography trait morphologique du sol type de sol utilisation des terres vegetation