An Investigation on the Cause of Thresholds of Gulling Initiation and Gulling Processes in Semi - Aird Mountains

In the study area, the development of gullies and gulling processes are very complex regarding geological stuctures, lithological factors and surface materials. Soil condition, topographic and climatological factors represent very vulnerable base for gulling processes. In this study, all these factors were examined in the laborator and the field. The results show that the role of soil moisture and climatological factors (e.g storms and temperature) are important in gulling processes. In the region, gullies develop at the foot of slopes because the surface of slopes is not covered with plant in the early spring and autumn or disturbed by human activity. The role of litological factors and type of surface materials are very important parameters in gulling processes. The major portion of gulling, especially linear one head – gulling and polymorph gulling are growing on old alluvial, Silt and Marl.