A Model for Determination of Range Suitability for Sheep Grazing Using GIS (Case Study Taleghan Region in Tehran Province)

Range suitability is one of the most important factors in rangeland management. Since all of rangeland ecosystems component affect range suitability their investigation about them is very difficult. In this study physical and vegetation factors were evaluated. Tree models, including production model, water model and erosion sensibility model made final model. FAO (1991) method (recommended for land capability evaluation) was used for suitability classification. The study area is located in 50˚, 36َ, 43ً - 50˚, 53َ, 20ً longitude and 36˚, 5َ, 19ً - 36˚, 19َ, 19ً latitude, in the middle area of Taleghan watershed, with the area 37977 hectares. According to the results, among physical characteristics; slope, sensibility of stone and soil to erosion, elevation, and among vegetation attributes cover, production, range condition and range condition trend together are most effective factors for determining suitability classification. In the study area the most limiting factors are high slope, changing of rangeland to dry farming, presence of stones sensitivity to erosion, poor cover and early grazing. On the other hands, much ground cover including vegetation cover, stone and pebble, good distribution of water resource, number of water resources and presence of perennial species increase Taleghan rangeland suitability for sheep grazing.