Developing an erodibility triangle for soil textures in semi-arid regions, NW Iran

- The high dependency of soil erodibility on the soil textures in the semi-arid area
- The remarkable role of soil moisture content in controlling runoff and erodibility in the fine textured soils
- Large variability of soil erodibility from an event to other event with increase in silt and clay content
- Developing a model to estimation of the erodibility of semi-arid soils using silt and clay content
- Proposing a soil erodibility triangle for rapid estimation of the erodibility in the semi-arid area

There is a strong need to develop a simple method for rapid estimation of erodibility using readily available data. In this study, soil erodibility was measured using eleven soil textures at the plot scale (60 cm × 80 cm) on a slope of 9% in a semi-arid region. A total of 110 soil erosion experiments were conducted using ten simulated rainfalls (50 mm h− 1 for 30 min). A regression model was developed based on silt and clay content (R2 = 0.82, p < 0.001) and was applied to estimate erodibility for 231 soils in the textural triangle. Kriging was used to spatial interpolate erodibility using these data to unknown soils on the textural triangle. A soil erodibility triangle was developed using kriging technique and its accuracy was evaluated using seven other soils. The technique showed a 5.4% error and allowed the prediction of soil erodibility in semi-arid areas by using the soil erodibility triangle.