Using Cesium-137 to estimate soil particle redistribution by wind in an arid region of central Iran

Abstract

This study was conducted to estimate soil erosion and deposition rates along a transect using 137Cs technique in an arid of Isfahan Province, central Iran. Sixteen sites along a northeast-southwest transect with 42 km length were used. Eighty soil samples collected from five depths (0-5, 5-10, 10-20, 20-30, 30-50 cm) were analyzed for 137Cs concentration. Additional 20 soil samples were collected from the reference site for computing soil loss and deposition using 137Cs measurement. The results showed that the northern part of the transect showed erosion rates ranging from12.90 to 46.86 t ha-1yr-1. The major factor affecting soil erosion process in northern part of the studied transect is associated dominantly with occurrence of improper gypsum mining operations and human activities. In the southern part of the transect deposition rates changed between 3.10 - 7.44 t ha-1yr-1, presumably influenced by increasing plant cover. Significant correlations between 137Cs and magnetic susceptibility, soil organic matter (SOM), total nitrogen (TN) and particle size distributions indicated that soil redistribution by wind erosion might have modified the soil properties along the studied transect. A multiple linear regression model was developed for estimating 137Cs by frequency dependence (χfd), TN, clay and sand contents which explained about 87% of the 137Cs variability. This study of using 137Cs to assess wind erosion is unique in the arid region of central Iran and had significant implications for further research.

Keywords

• 137CS inventory
• oil redistribution
• wind erosion