Spatial analysis of the geomorphic evolution of Tigris River basin using developed ArcGIS-Morphometric toolbox

Studied parts of Tigris river basin extended over an area of about 202702 square kilometres mostly extended within Turkish, Iranian and Iraqi territories with a narrow area in Syria and located between latitudes 32° 30' to 38° 30' N and longitudes 40° 00' to 48° 00' E. The basin is characterised by a complex topography, lithology, and structural features, which have impacts on the geomorphic development stages of the sub-basins. The study aims to evaluate the geomorphic stages of the river sub-basins based on hypsometric and volumetric analysis of each sub-basin using ArcGIS-morphometric toolbox developed by the author. The analysis was carried out using SRTM one arc-second DEM data. The basin is divided into 34 sub-basins and the hypsometric and volumetric parameters i.e., area, elevation, volume ratios, hypsometric and volumetric curves and integrals are calculated. The results show Tigris river basin has been passing in the Monadnock phase, while the sub-basins are classified into three geomorphic development stages i.e, middle - later maturity stage, early Monadnock phase and later Monadnock phase. According to the hypsometric curves, hypsometric integral, volumetric integrals; most of the sub-basins are passing in steady state of erosions and weathering processes with the prevailed fluvial system, terrain slopes and rock types.