quaternary evolutions of mountain valleys by using contour lines case study (sabalan mountains)

condition of contour lines in topographic maps, explains more geomorphologic issues such as effective processes in the land forms found in nature. change in the curvature of the transverse profile of a valley in mountainous areas, the peak of the mountain range, also reflect the geomorphologic features and expresses the tectonic events and climate changes occurring in the region. these changes are traceable along the valleys, according to the width of the valley floor to the height of its sides or curvature coefficient of rate curve. through examining this curvature at different heights, we can determine changes in the valleys and express on how to operate the various processes of exploration and cumulative throughout the valley. in this article tried that, through classical methods and mathematical analysis, all major sub-basins and valleys around sabalan be examined. using main rate curved lines flection coefficient, with the height distance of 200 meters, and if necessary with shorter distance (50 meters), addressed to identify the part of mountain, that had been indicate the location’s focus of geomorphological processes over time. to this end, for the 21 major basins of sabalan, prepared some table and relationship, which represent the way of arrangement of the transverse valley profiles at different altitudes is associated with processes. studies in sabalan, suggest that in the height of 2800 meters has been the place of changes in geomorphological processes, over time.