Geomorphic anomalies in Uttarakhand, India: A GIS-based approach for active tectonics

Natural destructive forces produced by active tectonics have the potential to alter the geomorphology of any terrain. In this work, Uttarakhand was selected as a study region to study the influence of active tectonics through geomorphometric analysis. In addition, the geomorphic parameter anomaly was compared with the seismicity data of Uttarakhand. The digital elevation data was analyzed on the GIS platform to evaluate the geomorphic parameters in 22 selected basins of the 4th-order. The computed values were grouped into three active tectonic classes - high, medium, and low. The significant findings of this study identify Uttarkashi, Chamoli, and Pithoragarh districts of highly dissected heterogeneous landforms that contain higher drainage bifurcation with a higher dendritic pattern of drainage streams, higher relief, higher frequency of earthquake events, low erosional potential due to strong lithological resistance, and the youthful phase of basin landforms with narrow and steep V-shaped valleys. History of seismic events suggests strong active tectonics dominance in the aforementioned districts due to the various active seismotectonic features such as the MCT, Vaikrita Thrust, Almora Thrust, Tons Thrust, Bhilangana Thrust, etc. Moreover, the results can also be employed to estimate seismic hazards and assist in disaster mitigation and management strategies.