Survey neo tectonic role in create river trace Case study: Gilanegharb river- north golanegharb city

Neo tectonics is one of the factors in the formation of river terraces in the northwestern Zagros. This study examines the impact of the neo tectonics on the formation of river terraces along. In equality in the number of terraces and their height in both sides of Gilan-e-gharb river comprises the main issue in this study. For this، at first the assessment of activity of the neotectonicsarea was performed by using geomorphic indicators (SL، S، smf) and geomorphological evidences of neo tectonics activity in the area. To examine the effect of the neo tectonicson the formation of river terraces، three topographic profiles in the beginning، middle and end of understudy interval of the riverwith different distances from Gilan-e-gharb thrust were analyzed. The quantitative results of geomorphic indicators and studying geomorphologic evidence simplicate on severity of neo tectonics activities in the region. Investigation of terraces profile indicates asymmetry of terraces in both sides of the river such that three terraces in the left shore and in right shore، along river close to Gilan-e-gharb thrust، respectively 3، 4 and 5 terraces were formed that the height of this terraces from riverbed does not equal. So، in regard to inequality in the number and the height of the terraces and increasing the number of terraces near Gilan-e-gharb thrust، we can conclude that neotectonics is the main factor in the formation and existing disorders in the number and height of terraces. In this study 10m Digital Elevation Model، 1:20000 aerial photographsin 1968 and IRS satellite images as study data، were used and field surveys were utilized to identify geomorphological evidences.