Analysis of Tectonic Status of Lavasan Sub-Basins Using Geomorphic Indicators and Radar Images

The tectonic positioning of Iran has led to significant seismic activity in the region, particularly in the Alborz Unit. This study focused on investigating the morphotectonic status of Lavasan Sub-basins located on the southern slopes of the Alborz. To achieve this, a digital elevation model with 30-meter resolution, a 1:50,000 topographic map, a 1:100,000 geological map, and Sentinel-1 radar images were utilized as research data. The analysis employed GMT, ArcGIS, and SPSS software, along with specific indicators to assess the tectonic condition of the region. The research was conducted in two stages. Firstly, the tectonic conditions of the sub-basins were evaluated using morphotectonic indicators and secondly, the vertical displacement of the region was assessed using radar images and the SBAS time-series method. The results of the study indicated that Lavasan Sub-basins exhibited high tectonic activities with Barg and Kond basins averaging a score of 1.88 and Lavasan and Afjeh basins averaging a score of 2. Consequently, the latter basins demonstrated a more active tectonic status based on the IAT index. Additionally, the results obtained from the SBAS time-series method over a 3-year period (from 01/06/2016 to 12/21/2018) revealed a 79-mm elevation and a 14-mm depression, which could be attributed to tectonic activity, thus corroborating the accuracy of the results obtained from morphotectonic indicators.