GIS-based approach for the measurement of variability in tectonomorphic signatures using DEM's data: a case study from the Habo Dome in the Kachchh area, India

摘要

The Kachchh region of western India is located in a plate interior region, but falls under one of the highest seismic zones of India, having very active crustal deformation and erosion. The drainage system, as well as the geomorphic evolution of the region under a semi-arid climate zone with high to very high strength of rocks in areas with high relief, is dominantly controlled by the seismic instability associated with continual tectonics. In the present paper, we have analysed a block close to the epicentre of the 2001 Bhuj earthquake to understand the role of relative active tectonics in the evolution of domal landscape morphology. Shuttle Radar Topographic Mission Digital Elevation Model data were used to extract drainage network in the GIS platform and evaluate active tectonics using different geomorphic indices of the Habo Hill, the second largest domal structure situated in Northern Hill Range of the Kachchh region. The average cumulative weightage of different geomorphic indices provides a quantitative tool, Index of Relative Active Tectonics (IRAT), which shows significant variations in and around the Habo Dome. Activation of earlier lineaments and generation of new lineaments controlled the morphometric evolution of the fault bound block of the region to form the Habo Dome. The undulating topography in addition to the domal shape of the study area resulted from the differential movements along several active transverse faults striking NE-SW, N-S, and NW-SE, and the regional faults striking E-W (the Kachchh Mainland Fault, the Kas Fault, and the Jikadi Fault). Stress propagations from the Himalayan range in the northeast and Suleiman range in the northwest are identified to be the causative factors for active tectonics and drainage anomalies in the area.