Producing Rangeland Capability Map Using Multi Criteria Evaluation Methods in Different Risk and Trade-off Levels (Case study: Plasjan Sub-Basin)

Rangelands are important ecosystems with diverse functions in the land that are at risk of destruction. The purpose of this research is to evaluate and determine the areas with potential to carry out rangeland activities under the Plasjan watershed.

By reviewing the sources and by Delphi method, the criteria, sub-criteria and limitations of the study were determined. The weights of the criteria were calculated by hierarchical analysis (AHP) method and the layer maps were standardized using fuzzy proportional functions. The rangeland rangeability of the area was determined using multi-criteria assessment (MCE) and with weighted linear combination (WLC) models and weighted sorted averaging (OWA) with medium risk and compensatory capability.

Rangeland capability maps were produced in 6 classes from without range capability to with very high range capability classes. Results have shown in the WLC model, 69249 and in OWA model, 54589 hectares were related to very high capability class. Sparse rangeland in WLC and OWA models, repeatedly with 22981 and 19187 hectares had highest portion in range land capability maps.

Results of this study have shown in WLC model due to high rate of trade-off in comparison of designed OWA model, wider area considers in high and very high range capability class that is related to major area functions that are water reservation and Animal husbandry. This study has shown importance of vegetation characters, land shape and soil character for determining rangeland capability of an area.