Range classification and evaluation using Geographic Information System (GIS) and Normalized Difference Vegetatiosn Index (NDVI) (Case study: Hablehrood subwatershed of shahrabad basin)

Evaluation of canopy rate، production، condition and trends of rangeland is important because of their role in preservation of water and soil resources. The aim of this research is to range classification and evaluation of rangelands of some part of Hable rood catchment using Geographical Information System (GIS(and Normalized Difference Vegetation Index. To do it، range classification was done using field work with Physiognomic- Floristic method along with vegetation sampling in a Stratified random sampling form. To define the condition and trends of the rangelands، the methods named four-factor and orientations were used in row. In this research، to increase the accuracy of the border of final vegetation types، land form unit map and composition of land form unit map with Normalized Difference Vegetation Index (NDVI) map were used in ArcGIS 9. 3 surrounding and the border of vegetation types were corrected. Land use map is provided using fuzzy method in the ERDAS IMAGINE software، and then، using Normalized Difference Vegetation index and field work، with respect to the canopy density the rangeland were divided to the three classes named dense range، semi dense range and low dense range. The results indicated the separation of for vegetation types. Also، rangeland was divided to the three categories named good، moderate and weak rangeland with respect to the vegetation canopy. The type named Astragalus spp_ Artemisia sieberi has a moderate condition while the 3 other types have weak condition. Also، all of the 4 vegetation types in the studied area have minus trend. Using GIS and vegetation index can be an effective tool in vegetation type and classification with high accuracy