Assessment the impact of soil physicochemical characteristics on the development of gully erosion (Case study: Darrehshahr Township)

This study was performed to evaluate the effect of soil physicochemical characteristics on the gully expansion in the Darrehshahr Township of Ilam Province, Iran. In this regard, 36 gullies were selected. The soil physicochemical properties and geometry characteristics of gullies were tested using aerial photography, the digital maps, and field operations. The multiple regression was used to determine the impact of these factors on each gully geometry characteristics and to establish relationship between dependent and independent variables. The results showed that EC, SAR, and Na have the highest impact and play the most important role in the development of gully. Whereas amount of organic matter and total of Caﯣ⃻ prevent gully development because of their soil adherence and flocculating nature. Moreover, based on the cross-section development model, the amount of SAR and the Na had the highest impact in the increasing cross section of gully. However, the amount of gypsum and total of Ca and Mg play the most important role in control and prevent of the gully development.