Comparative Evaluation of Wind Erosion Intensity Modeling using WEHI and IRIFR Models for Presentation of Segazi Plain Management in Isfahan

Wind erosion is one of the phenomena which causes land degradation in arid and semiarid regions and is a serious challenge for sustainable production and farmland management .So given the importance of the subject, the purpose of this study was to evaluate the wind erosion intensity in Segzi plain of Isfahan using two models of WEHI and IRIFR and to compare the results with ground reality to select the best model, together with providing and proposing management plans to mitigate the effects of wind erosion risk based on the superior model. The wind erosion hazard severity maps generated in this study can be an effective tool for managing and mitigating the effects of wind erosion and land degradation.

IRIFR method was used to evaluate wind erosion. In this method, 9 important and effective factors in wind erosion along with scoring table are provided and analyzed.The Australian Wind Erosion Hazard Index (WEHI) has been provided to predict land sensitivity in 2014. WEHI is a land erodibility modeling framework that utilizes a general rule of thumb to a set of surface and climatic thresholds and act through Geographic Information System (GIS) to predict landscape erosion sensitivity. Selected indices in order to estimate wind erosion in the WEHI model includeing soil moisture, wind speed and ground cover percentage. By multiplying the wind speed in the percentage of bare soil and dividing by the percentage of soil moisture, the amount of wind erosion is obtained in four classes of low, medium, severe and very severe. After comparing the results of the models with terrestrial reality, the model which possesses the highest correlation with terrestrial reality is selected as the top model and based on this, management plans are provided in the region.

The results of IRIFR model showed that wind speed and condition factor with score of 276 as well as soil and its surface cover with score of 212 are the most important factors in wind erosion and sediment production potential in the study area. The results of the WEHI model also show the intensity of wind erosion in the Lands planted by hand work units with wind erosion facies, sandy zones and transport area. Due to the higher correlation of the WEHI model with ground reality, proposed management plans based on the resulting wind erosion map were presented in three groups and seven implementing strategies in the study area.

Comparison of the two models of ERIFF and WEHI showed that the ERIFF model is suitable for dry climatic conditions in Iran and performs well, but needs to be further refined. This study has shown that the use of simpler, more up-to-date and with more capabilities models that capable of assessing wind erosion at different scales on a monthly to annual basis such as the WEHI model is an urgent need for future research in the country.