Quantitave analysis of tectonic activity in the Gavkoshak of Kazeroun Watershed by morphometric indices

Morphometric analysis is considered as quantitative evaluation of geometric features landforms and landscape. In the study of basin tectonic features, the use of some morphometric parameters can provide very substantial information. Gavkoshak Basin with an area of 46.73 km2 is located in Zagros simply folded belt. The objective of this research is to use the morphometric indices such as hypsometric integral, basin shape, stream length-gradient, asymmetric factor, and the valley width/height ratio. As a result, these indices are converted to the tectonic activity index. This index can be used to assess the overall performance of the region's tectonic activity.Morphometric indices of area are studied by dividing this area into 43 sub-basins, using the Digital-Elevation Model (DEM) and Geographic Information System) GIS). Morphotectonics index method with the use of geographic information systems provide procedures and a powerful tool for estimating tectonic activity in the region. It should be borne in mind that the results of these indices can show different values in different sectors. By examining the relative index of tectonic activity, the basin in this research is divided into two parts namely active (25.6% of the watershed) and semi-active (74.4 % of the watershed). Through statistical analysis, the area under investigation includes four clusters: cluster one with 91. 83% similarity, cluster two with 95.19% similarity, cluster three with 96.18% similarity, and cluster four with 91.09% similarity. In this way, homogeneous regions were determined based on clustering algorithm ward. The active tectonic basin in this research can be studied in another research project, using other morphometric parameters.