Analysis tectonic role in river terraces geomorphologic evolution Ghezel Owzan

Review of river terraces is main issues related to river geomorphology. They are areas with low slope that is parallel to the axis of the river valley and are in the higher levels of the river bed and created through cutting the river bed and response to changes in external factors such as climate, tectonics and base level. Ghezel owzan River is as one of the longest river systems in the country, responded well to changes in external factors (climate, tectonics and base level). For this purpose, after dividing the river into nine periods, Profile was drawn on the terraces adjacent faults in order to study in terms of height level and symmetry. In order to assess the effect of Tectonic activity on Ghezel owzan Catchment area, Four sub-basin are studied: Divandareh, Zanjan rood, Gharanghochay and Hashtchin- Tarom, from Upstream to downstream , With the help of two indicators, River Gradient length (SL) and Valley floor width to valley height (Vf) by determined sections, The results indicate the relationship building terraces with tectonic factors. This means that form terraces in downstream river is more a reflection of the effects of neo-tectonics and tectonic if they originate, reflecting the effects of tectonics. Feedback such activities is in basin downstream for nested alluvial fans and vertical-walled terraces in bedrock and in the mirage nested terraces in alluvial sediments with low sides slope.