ABSTRACT
The land suitability map in general is established based on individual crop which provides inadequate information for land use planning. This evaluation is then formulated with objective of delineating units of land as to their suitability for combining economic crops with regarding the legal conservation areas. The study area, Chi watershed, covers extensively in Northeast Thailand with an area of about 49,500 sq km. The major economic crops in the area are rice, sugar-cane, cassava and rubber tree. The suitability assessment for each crop was conducted using the method as described in FAO guidelines. For each crop, land suitability unit was established using overlay process of the defined theme layers or land qualities. As a result the suitability map with their associated class attributes for rice, sugar-cane, cassava and rubber tree were carried out. In addition, the conservation areas in the watershed were also digitally encoded in GIS database. Simultaneously, overlay process was then performed of the suitability layers and conservation areas with selection criteria of identifying conservation area, highly and moderately suitable classes. The resultant map obtained is a result of combination of defined suitability class of combining crops and the conservation areas. The planning alternative that best matches land uses to the highly and moderately suitable land areas was suggested with respect to the conservation area.