Evaluating and modelling wind erodibility indices in salt-affected arid soils: Insights from the Sistan alluvial plain, Iran

Wind erosion poses a severe threat to land degradation in arid regions, particularly where soil salinization compounds the problem. This study identified key soil factors controlling wind erodibility indices in salt-affected soils of the Sistan alluvial plain, eastern Iran. Surface soil samples ( n = 181) were analyzed for laboratory-based indices (Erodible Fraction, EF; Dry Aggregate Stability, DAS) and ten estimation indices. Soil properties were grouped into salinity/sodicity attributes (pH, electrical conductivity, EC; sodium absorption ration, SAR; soluble sodium, Na; soluble potassium, K; soluble calcium, Ca; and soluble magnesium, Mg) and physical/chemical properties (sand/clay ratio; silt; bulk density, BD; saturation percentage, SP; organic matter, OM; cation exchange capacity, CEC; and calcium carbonate equivalent, CCE). Using correlation, structural equation modelling (SEM), and path analysis, we found that laboratory indices EF and DAS were more reliable than most estimation models, although Estimated soil erosion rate (ESER) performed reasonably. The sand/clay ratio, SP, Na, EC and SAR positively, while silt, OM, CEC, and CCE negatively influenced wind erodibility. SEM revealed that physical and chemical properties had a stronger mitigating effect on wind erodibility than salinity/sodicity attributes. Due to the poor performance of existing pedotransfer functions in this region, new equations for predicting EF (R 2 = 0.66) and DAS (R 2 = 0.53) were developed using path analysis. These regionally-calibrated models offer a practical, two-tier decision framework for land managers: (1) identifying hotspots requiring immediate surface protection based on SAR and sand/clay thresholds, and (2) scheduling soil amendment (OM addition) to reduce erodibility before the peak windy season. This transforms routine soil data into actionable management intelligence.