Multi-criteria land evaluation, using WLC and OWA strategies to select suitable site of forage plantation (Case study; Zakherd, Fars)

Employing a vast variety of information and complexity of analyzing thematic and spatial data، simultaneously together، are the main reasons to use Geographical Information systems to solve land allocation problems. Multi-Criteria Evaluation is a method to compromise relative importance of participating factors and to integrate the factors according to their importance in decision-making. Current research employed MCE techniques to solve one of the most important problems in natural resources management; allocating land for cultivating forage. The main hypothesis is to use MCE and AHP techniques in GIS to allocate land for cultivating forage. The Study area، Zakherd Watershed، is about 8222 ha، located in north-western part of Shiraz، Fars Province. The Research method is based on integrating AHP and MCE in GIS for location-allocation problem solving. Two Strategies of weighted linear Combination (WLC) and Ordered Weighted Averaging (OWA) selected for combining thematic maps. The results indicate WLC is a more Conservative method the OWA. However; the Overall Agreement of the Comparing the results، derived from the strategies، is about 95%، the strategy WLC is more conservative than OWA. It allocated more lands in the 2nd and 3rd classes of suitability. It allocates much more lands to the second level and the third of suitability. The results derived from the strategies have been compared to the result of ecological land suitability evaluation. It indicates that the area، ecologically suitable for cultivating forage could be classified into 3 sub-classes of land suitability، which provides watershed managers with more decision options. It seems it is a critical step to determine weight of importance of the factors than integrating method in decision-making so the cultivating limitations caused an intendancy of the results، to be same.