morphotectonic analysis of Gharajeh basin located in East Alborz

With recognition of tectonic affects in many fluvial systems find out that, rivers are valuable tools for use in studies of active tectonics. Study of stream channels and their associated deposits offset by faulting may reveal the amount displacement at particular site information that is critical in evaluating future earthquake hazards. Study area is located at the NE Iran (East Alborz) and west of Bojnurd city. Aim of this research is separating high tectonic activity areas from low tectonic activity areas. In this research, in order to evaluate rate of tectonic activity the drainage basin asymmetry factor (Af), Transverse topographic symmetry factor (T), hypsometric integral (Hi) hypsometric curve (Hc), stream-gradient index (SL), valley floor width–valley height ratio (Vf) were calculated. Faults and fractures of the study area are extracted from VNIR band of Aster image, Morphometric indices computed using GIS and Global mapper. In Gharajeh basin most values of SL is related to low strengths rock, increasing SL index in soft rocks show recent tectonic activity in study area. Result of this research shows that northern side of Qharajeh basin is inactive part of study area and southern side of Qharajeh basin is actives part of study area. This tectonic activity is related to structural growth from north to south in this area.

کلیدواژه ها:

Morphotectonic ، Drainage basin ، Geomorphic index ، East Alborz