توصيفگر ها :
فرسايش بادي , عناصر سنگين , ريسك اكولوژيك , گرد و خاك , تحمل گياهان به آلودگي
چكيده انگليسي :
The phenomenon of wind erosion and dust generation in the arid and semi-arid regions of Iran—particularly in the Sejzi area, located in the eastern part of Isfahan Province—is recognized as one of the major environmental, health, and economic challenges. This region, due to its dry climatic conditions, fragile geological structure, reduced vegetation cover, and intensive human activities, has become one of the main centers of erosion-related crises in the country. Accordingly, the present study was designed and conducted with the aims of quantifying the intensity of wind erosion, assessing the environmental risk of heavy metals associated with dust particles, and determining the Air Pollution Tolerance Index (APTI) of plant species. In the first phase, 13 major wind erosion events were monitored between October 2022 and August 2023 using a field observation station installed in the Sejzi plain. For each event, parameters such as sediment transport capacity, particle movement patterns (saltation, suspension, and surface creep), and soil loss were determined. Spatial zoning using Surfer software revealed that the southern and central parts of the area experienced the highest erosion intensity. In addition, the SWEEP model was applied to simulate the events. After calibration based on the Almaras roughness coefficient, the model’s coefficient of determination (R²) improved from 0.78 to 0.94, indicating a high level of accuracy and consistency with field data. In the second phase, dust samples collected by MDCO traps were analyzed chemically, and the concentrations of heavy metals such as Pb, Cd, Zn, Ni, and As were measured. Risk assessment using indices such as RI, Er, and Cf showed that with increasing wind speed, the concentration of pollutants in airborne particles rose, and some areas fell into the “high to very high” environmental risk category—posing a serious threat to human health and the ecosystem. In the third phase, in order to identify tolerant plant species suitable for soil stabilization and vegetation restoration projects, 104 plant species in the region were evaluated. Their APTI values were calculated based on four parameters: total chlorophyll content, leaf extract pH, ascorbic acid content, and relative transpiration. The results indicated that Salsola rigida (Qareh Dagh), Carlina sp., and Echinochloa sp. (Jaghejagheh) exhibited the highest tolerance to air pollution. The families Chenopodiaceae, Asteraceae, Poaceae, Fabaceae, and Zygophyllaceae represented the dominant groups among the tolerant species. Overall, the findings of this research demonstrate that integrating erosion modeling, pollution risk assessment, and plant bio-indicator analysis provides an effective approach to understanding and managing wind erosion phenomena in Iran’s arid regions. This integrated strategy can serve as a foundation for planning erosion control, ecological restoration, and the selection of resistant plant species in other critical erosion-prone areas across the country.