Morphomertic analysis of sub-watersheds to evaluate relative tectonic activity. a case study of the Northeastern Algeria. (Tebessa)

Abstract

A neo-tectonic analysis was published using remote sensing technical and a geographical information system (GIS) to better understand the characteristics and evolution geomorphometric of the immense Morsot-Tebessa-El Hammamet watershed. This study extracted geomorphometric indices such as integral hypsometry (HI), the sinuosity of mountain fronts (Smf) and the valley width index. (Vf), and drainage anomalies by defining the Asymmetry Factor (Af) and the topographic factor (T) to analyze tectonic activity and its implications for the development of relief and flow characteristics.The extracted index data was aggregated and integrated into a GIS to create a new index named the Relative Tectonic Activity Index (IRAT). The mean of these geomorphometric indices was used to estimate the distribution of relative tectonic activity in the study area. Thus, the relative distribution of tectonic activity in this zone to determine the degree of IRAT, we created four classes: class 1 very high (1 IRAT 1.5); class 2 high (1 IRAT 1.5); class 2 medium (1.5 IRAT 1.9); and class 3 low (IRAT > 2).We were able to identify the highly deformed areas associated with active tectonic anomalies and conclude that the reactivation of underground faults, which coincides in space with the mapped faults in the outcrops activated from the since Miocene, influences the migration of sub-basin hydrographic systems in two dominant directions.The geographic correlation between these faults and subbasin geometry, the change in river sinuosity when crossing these limits, and a high concentration of tectonic lineaments along these limits all support this explanation. As a result of this research, iIt was possible to (1) determine the regions morphotectonic evolution and the correlation between the increase in this index and the degree of accentuated terrain deformation, (2) provide geometric details for some previously unknown tectonics. and (3) present a new diagram on the spatial evolution of morpho-structural structures in close relation to recent tectonic activity in the region.