Investigation of Geomorphological Forms of Goyjah Bel Basin in Ahar Plain

Abstract

Geological and geomorphological studies as the basic studies, play a key role in watershed, soil protection and flooding management projects. Goyjah Bel basin is located ten kilometers southwest of Ahar County. The study area is a part of Aharchay River watershed, which joins Qarah Su River and then Aras River. The mentioned basin is located in the structural zones of Alborz and Central Iran and is composed of various rock-sedimentary units due to its vastness and geographical location. The morphological appearance of this basin is affected by two mentioned zones and the trend of structures in the northwest-southeast region. In the formation of these structures, factors such as the collision of Iranian and Turan plate, the performance of thrust faults and finally the performance of northwest-southeast strike-slip faults have played a role. The morphology of the basin mainly includes mountains and hills.This was a descriptive and analytical research based on field and library studies. Spatial data of this research included the satellite images, topographic maps (1.25000), aerial photographs and geological maps (1.100000) which the types, units and facies of geomorphology were determined by them. In the study area, three units, three types and seven geomorphological facies were identified. The most dominant geomorphological unit was Hill unit with an area of 3665.1 hectares, occupying 49% of the total basin. In addition to the Hill unit, the mountain unit also has a very large area, but the plain and river unit covers a small area. Various morphological forms in the study area include anticlines, synclines, alluvial cones, sedimentary dams, canals, ditches, grooves, landslides and various types of canal wall collapse movements.