Assessment of Relative Active Tectonics using Morphometric Analysis, Case Study of Dez River (Southwestern, Iran)

This paper present a new method for evaluating relative active tectonics based on morphometric indices useful in evaluating morphology and topography. Indices used include: Bifurcation ratio (BR), Basin Relief (Bh), Drainage Density (DD), Ruggedness number (Rn), Stream frequency (Fu), Form Factor (FF), Shape Factor (Ll), Sinuosity (Sl) and Elongation ratio (Re) of drainage basin. Results from the analysis are accumulated and expressed as an index of relative active tectonics, which we divide to from relatively low to highest tectonic activity. The study area in the central Zagros fold - thrust belt of the south western Iran is an ideal location to test the concept of an index to predict relative tectonic activity on a basis of area rather than river system or mountain front. The study area has variable rates of active tectonics resulting from the collision between the continental Arabian plate and the so - called Iranian block belonging to Eurasia that has produced linear NW - SE anticline forms and thrusts. We test the hypothesis that areas of known, relatively high rates of active tectonics are associated with indicative value index of relative active tectonics.