Evaluating the effect of tectonic in the morphometric characteristics of drainage systems and triangular facets of Danehkhosk anticline

Danehkhoshk anticline is a typical growing anticline in Kermanshah province which is located in Folded Zagros belt. The purpose of this research is to evaluate the effect of tectonic on the triangular facet characteristics، the drainage density and on the drainage pattern formed on anticline. Dimensions of triangular facets were determined by means of Quickbird satellite images and field works. Drainages were derived from topographic maps and satellite image and then imported in ILWIS (Integrated Land and Water Information System) software. Stream ordering was performed based on Strahler method and then lengths of all order were calculated. The dips of strata were measured at mountain front by clinometer. Studied anticline was classified into 8 tectonic zones، based on measured dips and width of anticline limbs. Means of strata dips، lengths of triangular facet bases، areas of triangular facets، and drainage densities of first order rivers in all zones were computed. Results of this study show that there is meaningful positive relation between means of strata dips and mean lengths of triangular facets bases، with appropriate correlation coefficient (92%)، so that means of length of triangular facet bases increase with increasing means of strata dips. Also، means of triangular facet areas increase with increasing means of strata dips. This research shows that triangular facets have been formed only in zones with steeper limbs (zones 3، 4، 5). Results of this study reveal that values of drainage density of first Order Rivers increase as width of limbs of anticline decrease so that the maximum value of drainage density of first order rivers (3. 39) is associated in the narrowest zone (8). This research also shows that upstream part of drainages on northwest and southeast ends of anticline curve towards the centre of the anticline that is indicator of lateral growing of Danehkhoshk anticline towards northwest and southeast. Overall، results of this paper reveal that parameters like triangular facets، drainage density of first order rivers، and drainage pattern are appropriate criteria for determining active tectonics and their local differences in Danehkhoshk anticline.