Evaluation of relative tectonic activity in a semiarid basin: analysis of geomorphic indices and morphometric parameters in the Meskiana watershed

Tectonics is the scientific discipline concerned with the investigation of rock deformation within the Earth's crust and the forces that instigate such deformation. The comprehension of tectonic activity within a particular geographical area stands as an indispensable pursuit, as it serves to elucidate the intricate mechanisms responsible for the genesis of landforms and seismic behavior. The main objective of this study was to assess the relative tectonic activity (RTA) prevailing within the Meskiana basin, NE Algeria. This assessment was based on a multifaceted synthesis of geomorphic indices and morphometric parameters; characterizing landform features to infer tectonic influences. The methodology involved the utilization of various datasets, including the NASA Shuttle Radar Topographic Mission Digital Elevation Model (SRTM-DEM), geologic maps, satellite images, and fieldwork. GIS techniques and advanced geoprocessing tools were harnessed for the purpose of efficiently handling a diverse array of geographic data layers. The derived indices, namely the hypsometric index, asymmetry factor, transverse topographic symmetry, drainage basin shape index, stream length gradient index, valley floor width-to-height ratio, and mountain front sinuosity index, provide valuable information about the geological and tectonic processes at play in the Meskiana region. They give an understanding of the relative tectonic activity, landscape maturity, and deformation patterns, which is crucial for studying the Earth's dynamic processes and potential hazards like earthquakes and landslides. The analyses encompassed all 19 delineated sub-basins that collectively compose the Meskiana basin. By integrating the relative tectonic activity index (IAT) with the morphometric parameters, the study area was classified into four distinct classes. The results show IAT values of 1.71-2.42. These values represent the relative level of active tectonics in each basin. Basins with IAT values around 1.71-1.85 are classified as "high," indicating a relatively high level of tectonic activity. Basins with IAT values around 2.00-2.42 are classified as "medium," suggesting a moderate level of tectonic activity. The study emphasizes investigating morphotectonic features to enhance our understanding of tectonic activity in Neogene North African basins.