SUMMARY
Sustainable development links to a rationalistic and effective use of resources. Presently, growth in human needs for a variety of reasons causes a great pressure on the existing resources, which has induced in misuse-based deterioration of lands as well as increase in poverty and several kinds of social problems. In this context, due to rapid growth of population in Turkey, the most appropriate use of lands according to their potentials is essential, because sustainability of environments can only be achieved on condition that natural and cultural potentials are appointed and the land use is enforced in compliance with ecological properties. In previous attempts of land suitability analyses, the subject “the most proper use of land” has been the focus of several authors.In this study, land suitability analysis of the upper basin of the Kara Menderes River was carried out, which drains the Biga Peninsula, west of the Marmara Region in Turkey, on the basis of geographical information systems and analytical hierarchy process, a technique used for multi-criteria decision making studies. After the determination of suitability in terms of the main three land use types, i.e. agriculture, meadow-pasture and forest, an optimal land use map was produced and results were compared to the present-day land use situation. Based on optimal land use results, an area of 15.2% is suggested for agricultural activities. The area proposed for meadow-pasture lands corresponds to only about 8.5%. Forest areas constitute, however, the foremost class with the suggested value of 75,1%. When data from optimal land use is compared with that in the present-day conditions, it is noticed that the proportion of agricultural areas excesses the suggested value of optimal land use, as opposed to the proportions of forest and meadow-pasture areas having smaller distributions. This implies that some agricultural areas, which are recommended to be evaluated as forest and meadow-pasture areas herein, are presently used for agricultural purposes.