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 thegully expansion in the Darrehshahr Township of Ilam Province, Iran. In this regard, 36 gullieswere selected. The soil physicochemical properties and geometry characteristics of gullieswere tested using aerial photography, the digital maps, and field operations. The multipleregression was used to determine the impact of these factors on each gully geometrycharacteristics and to establish relationship between dependent and independent variables.The results showed that EC, SAR, and Na+ have the highest impact and play the mostimportant role in the development of gully. Whereas amount of organic matter and total ofCa+++Mg++ prevent gully development because of their soil adherence and flocculatingnature. Moreover, based on the cross-section development model, the amount of SAR and theNa+ had the highest impact in the increasing cross section of gully. However, the amount ofgypsum and total of Ca++ and Mg++ play the most important role in control and prevent of thegully development.