Support system based on GIS and weighted sum method for drawing up of land suitability map for agriculture. Application to durum wheat cultivation in the area of Mleta (Algeria)

Due to constant decrease in farmlands, it is important to identify the best lands for sustainable agriculture (productive and profitable agriculture that protects the environment and that is socially equitable). This requirement has resulted in the development of land suitability maps for agriculture by combining a range of factors. Spatial analysis approaches, based on the concepts of the weighted sum, combined with Geographical Information Systems (GIS) offer the opportunity to efficiently produce these land suitability maps. The functions of the weighted sum make it possible to assign numerical weights, to distinguish between positive and negative criteria and to rank alternatives. A spatial decision support system has been developed for establishing the land suitability map for agriculture. It incorporates a version of the weighted sum method SAW (Simple Additive Weighting), applicable to the vector data model, in ArcGIS within the GIS program package environment. This approach has been tested on the area of Mleta (Algeria) to assess the land suitability for durum wheat agriculture. The parameters and the classification system used in this work are inspired from the FAO. The coherence of results confirms the system effectiveness.