evaluation of the effects of vegetation characteristics on desertification (case study: northern hableh roud, iran)

one of the characteristics in iranian model of desertification potential assessment (imdpa) is vegetation. sincevegetation is very important factor in the degradation of land, so some indices were determined for this item in order toevaluate desertification potential of arid, semi arid and arid sub humid areas of iran. the indices included vegetationcondition, exploit and revegetation. to calibrate the vegetation item in the imdpa model, above mentioned indices wereassessed in northern hableh rood region as semi arid and arid sub humid region. to do this, in the first stage unit workmap of the study area was prepared based on slope, land use and geological maps. scores of indices were recorded indifferent study units. at last, using the following formula, vi  3vci *vui *vri , final score of vegetation character(vi) was determined in the study area based on imdpa. after scoring vegetation character, desertification intensity mapfor vegetation character including four low, medium, intensive and very intensive classes was prepared. the map showedthat 62.2%, 37.2% and 0.6% of the study area are considered as low, medium and high desertification intensity class,respectively. there wasn't very high class based on vegetation character.