Indian cities are expanding not only in terms of built environment but also in population. Multi-story buildings are rising rapidly to accommodate the growing population, undesirably even in hazard prone areas. Such a scenario calls for a proper disaster risk reduction program and plan to control the inevitable damage to lives and properties. Earthquakes are destructive only if the factors that increase the damages prevail. Attention should be given to crowded cities with people and infrastructure vulnerable to hazard. This study presents the details of deterministic seismic hazard analysis (DSHA) done for Coimbatore city of the state of Tamil Nadu, India using the latest available information on seismicity of the region. The earthquake data was compiled from different agencies and homogenized in a unified moment magnitude scale to create an updated earthquake catalog. Seismotectonic map for the study area was prepared by superimposing the earthquake events on the seismogenic sources. DSHA was then performed by dividing the study area into grids of size 0.02º × 0.02º (approximately 2 km × 2 km) using a MATLAB code, considering three different attenuation relationships for the stable continental region. Land use (LU) map for the region was developed from LANDSAT 8 data using various GIS platforms. Hazard contour map prepared using ArcGIS, was then overlaid on the LU map to comprehend the seismic risk of the region. It was observed that, though the wards south-west of the city shows higher Peak Ground Acceleration (PGA) values, the wards north-east of the city have larger and denser built-up areas, increasing its vulnerability, in the event of an earthquake.
Lalith Prakash E., Dr. Sreevalsa Kolathayar, and R, R., “Seismic Risk Assessment for Coimbatore Integrating Seismic Hazard and Land Use”, Proceedings of GeoShanghai 2018 International Conference: Geoenvironment and Geohazard. Springer Singapore, Singapore, pp. 117-124, 2018.