environmental impact assessment of sustainable development, using degradation model (a case study of horaman zone, west iran)

nowadays, environmental impact assessment (eia) is a one of planning tool that used for the prediction of environmental impacts. there are several methods to assess environmental impacts in the world. degradation model is one of the mathematics models that investigates and predicts data for assessing the impact of development. degradation model consist degradation coefficient per ecology unit, total severity of degradation factors of per ecology unit, physiological density (population in the ratio of arable land) and ecological vulnerability. in this survey, for studying environmental impact assessment, the first, domain of horaman zone was divided into 140 networks, (2×2 cm on a topography map 1: 250000) which that per one network was 2500 hectare. ecological vulnerability was calculated and classified by slope, height, hemisphere, herbaceous cover and settlement maps. in the next step, 24 factors of degradation in horaman zone were identified and severity all of them calculated by topography map, field researches, advice of experts and participates of native people. physiological density was estimated via dividing population of networks by splitting population of networks to arable land per network. finally, regarding to table of degradation and excel software, degradation coefficient was calculated and analyzed in each network. degradation coefficient for all networks categorized into 6 classes and 3 sets based on fuzzy set theory. therefore, all networks were compared together in respect of severity and measure of degradation and whole of the zone was spitted to three areas: a) capability of further development b) need to rebuild and restore and c) need to conservation. accordingly, 47.1% of study areas prone to further development, 50.6% were need to restore and rebuild and 2.1% of studied areas need to conservation operation.