Evaluation of Tectonic role on appearing and Change of Alluvial fans (Case Study of alluvial fan on the hillshade of Ghalajeh Synclinal)

Ghalajeh synclinal is extended on the south of Kermanshah province from northwest to southeast. Considering the permanent tectonic movements in Quaternary and current age in studied region, the alluvial fans of the region is a good reason for evaluation of such movements. The morphology and morphometry properties of alluvial fans are severely under the effect of the tectonic activities. The aim of this paper is to investigate the role of tectonic parameters in the appearance and change of region's Alluvial fans. In this study, the topography, geology maps and aerial photographs have been used as the main research data. The morphology of the region's alluvial fans was also studied. Then, using the geomorphic index (Vf, Sl, Smf), the intensity of tectonics of the region were evaluated, and with the calculation of the related formulas and coefficients, the necessary diagrams and maps were designed by ArcGIS 9.3 software. The results indicate that the region's tectonic (faults) have the main role on appearing and change of the region's alluvial fans, so that by omitting of Asmari Formation and exposed of Gurpi-Pabdeh loose Formation, appeared by GilaneGharb trust leads to more alluvial fans on the direction of this fault. The alluvial fans are arranged harmoniously with tectonic of Plio-Quaternery in the region.