A neotectonic statistical assessment through watershed geomorphic analysis: a case study in the Greater Zab River Basin, Turkey–Iraq

• Published in: Environmental earth sciences 2022-07, Vol.81 (13), Article 355
• Main Authors: Al-Attar, Zaid T., Othman, Arsalan Ahmed, Al-Hakari, Salim Hassan Sulaiman, Obaid, Ahmed K., Salar, Sarkawt Ghazi, Liesenberg, Veraldo
• Format: Article
• Language: English
• Subjects: Analytic hierarchy process; Asymmetry; Biogeosciences; Digital Elevation Models; Drainage density; Drainage systems; Earth and Environmental Science; Earth Sciences; Earthquakes; Elongation; Environmental Science and Engineering; Erosion processes; Fault lines; Geochemistry; Geographical information systems; Geological faults; Geology; Geomorphology; Hydrology/Water Resources; Modelling; Neotectonics; Original Article; Radar; River basins; Rivers; Seismic activity; Sinuosity; Slopes; Strike-slip faults; Surface roughness; Tectonics; Terrestrial Pollution; Valleys; Watersheds
• ISSN: 1866-6280; 1866-6299
• DOI: 10.1007/s12665-022-10478-7

The morphology of the Zagros Fold and Thrust Belt (ZFTB) tectonic region results from the collision between the Arabian and Eurasian plates. In addition to the variation in rock types and erosion processes, a significant feature that can reflect the effect of tectonic activity is the drainage system and the geomorphic indices. This study aims to assess the relative tectonic activity of the Greater Zab River Basin statistically and quantitatively. We used the digital elevation model (DEM) of the Shuttle Radar Topography Mission (SRTM) to extract ten geomorphic indices, which are elongation ratio (Re), basin asymmetry factor (Af), transverse symmetry factor (T), drainage density (Dd), sinuosity index (Si), valley floor width to valley height ratio (Vf), relative relief (Rhp), hypsometric integral (Hi), normalized channel steepness (Ksn), and surface roughness (SR). We applied the analytic hierarchy process (AHP) and technique for order performance by similarity to an ideal solution (TOPSIS) to evaluate the relative active tectonics by applying different suggested weights to each index using GIS techniques. The results of AHP and TOPSIS models applied to the selected geomorphic indices show that the central part of the study area exhibits high relative tectonic activity due to the interaction between three perpendicular strike-slip faults with the Zagros thrust. This interpretation is inferred from the inverse relationship between the relative tectonic activity and the distance from the Zagros Suture Zone. The earthquakes assemblage also supports the higher relative tectonic zone coincided with the zone of faults interaction. This study concludes that the quantitative assessment of relative tectonic activity of a region can be achieved by AHP and TOPSIS models application. The AHP and TOPSIS somehow perform similarly. However, the best accuracy can be obtained using the AHP model.