Exploring the Active Tectonics of Kalardasht and Abbasabad Basin based on Morphometric Indices

Morphometric indices are widely used as a tool for identifying and characterizing the deformed sections by active faults. So far, the relationship between active tectonics and morphotectonics has not been studied in the studied area. By determining active processes in the Klardasht and Abbasabad basin and taking the necessary measures, it is possible to avoid damages caused by natural hazards such as floods and earthquakes in this area. In this study, using morphometric indices, the basins of a part of Central Alborz were investigated in terms of the influence of active tectonics. So, the Klardasht and Abbasabad basin was analyzed using Hierarchical Anomaly Index (∆a), Longitudinal River Gradient index (SL), Form Factor Index (Ff), Drainage Density Index (Dd) and Relative Prominence Index (Bh) in 18 drainage basins of the specific area. Along the North Alborz, Khazar and Azarak faults, the amount of these indicators increased. So, it can be concluded that the tectonics of the studied area is active due to the activity of these faults. Finally, by determining the Relative Active Tectonic index (Iat), the region was zoned into four categories (very high, high, medium and low) in terms of the level of tectonic activity. In about 66.5% of the region, which is dominated by the activity of the main faults in the region. Other sub-faults formed by recent tectonic movements show moderate to high tectonic activity.