Seismic Hazard Analysis for Urban Territories: A Case Study of Ahmedabad Region in the State of Gujarat, India

An attempt has been made to estimate the seismic hazard at rock level in terms of PGA using a probabilistic approach. The detailed catalogue of historical and recent seismicity within a 350-km radius around the Ahmedabad region has been compiled and a new seismotectonic map has been generated. The completeness of the data should be checked before carrying out seismic hazard analysis; so, subsequently, it has been checked adopting different independent techniques. Finally, earthquake data has been analyzed statically and the seismicity of the region is evaluated by defining 'a' and 'b' parameters of the Gutenberg-Richter relationship. Eventually, a probabilistic hazard map corresponding to 500 and 2500 years of return period was developed for the region. Further, the Uniform Hazard Response Spectra with 5% damping was developed at both rock level and considering local site effects.