Abstract:
The Koyna-Warna area in Maharashtra, Western India, is one of the world’s best examples
of reservoir-induced seismicity. The occurrence of earthquakes in the vicinity of Koyna Dam (Shivaji
Sagar Lake) started since 1962, soon after the initiation of water impoundment. To understand the
tectonics and seismicity of the region, recent Landsat 8 images and Sentinel radar data were evaluated
in GIS, as well as SRTM and ASTER Digital Elevation Model data (DEM) and the DEM-derived
morphometric maps. Geophysical and climate data were also included in the GIS database. The
analysis of satellite data contributed towards understanding the tectonic framework of the Koyna
reservoir area by visual lineament analysis. Thus, Landsat 8 and Sentinel radar data brought out the
structural pattern and made visible larger fault zones. The detailed lineament analysis detected areas,
presumed to have rocks of relatively higher permeability, supporting intrusion and infiltration of
surface water. The resulting maps of weighted overlay procedures derived from causal morphometric
factors that influence the susceptibility to ground motion revealed areas with higher, medium and
lower susceptibility to soil amplification.
