Climate Modelling of Desertification in Haj Ali Gholi Playa

Desertification is defined as rapid change in vegetation cover, plant community composition, hydrologic conditions, soil properties, or climate conditions, which results in an overall loss of ecosystem services and poses serious threats to sustainable livelihoods. The process represents one of the most threatening environmental hazards due to the large amount of people and land at risk. Therefore, this research was aimed to modeling of desertification and zonation of Haj Ali Gholi Playa according to the climate parameters such as temperature, rainfall amount, evapotranspiration potential, number of sunny hours, climate condition, drought (aridity), and maximum prevailing wind speed, using GIS technique and statistical methods. The modeling was performed using stepwise multiple regression analysis. According to the results, maximum significant relationship was found among desertification classes and dry zone with a determination coefficient of 0.999 and STD error of estimate of 0.033 (α ≥ 0.01). Other results are included the zonation map of desertification in the study area from very high zone to no-desertification zone, so that, the very high desertification zone is included about 679.75 km2 (%92.66) of present land degradation and has the possibility of increasing up to 5668.11 km2. In addition, the high desertification zone, covering about 5.22 km2 (%0.44) of present land degradation, can develop to 933.86 km2. The obtained results from validation test of the model show the descending trend of accuracy assessment index from the very high desertification zone to the no-desertification zone, indicating the necessary accuracy of the model.