Spatial distribution of bedrock level peak ground acceleration in the National Capital Region of India using geographic information system

Abstract

The probabilistic seismic hazard analysis is conducted for the seismically active National Capital Region (NCR) of India, one of the most densely populated regions in the world, to quantify the peak ground acceleration (P GA) at bedrock level by considering seismogenic source characteristics, smoothened grid seismic zoning, magnitude recurrence model, uncertainties, and suites of suitable ground motion prediction equations. The spatial distribution of the resulting P GA value is presented using GIS for the entire NCR of India for 10% and 2% probability of exceedance in 50 years and 100 years. The estimated P GA values are found to vary in the range of 0.12 to 0.37 g and 0.15 to 0.40 g for a 2% probability of exceedance in 50 years and 100 years, respectively. And the P GA values range from 0.07 to 0.33 g and 0.08 to 0.35 g for the 10% probability of the exceedance in 50 years and 100 years, respectively. The results reveal that the eastern region of the study area falls under high seismicity due to its proximity to the Himalayan zone, a highly seismically active region. High P GA values are also observed for south-eastern regions of the NCR of India due to the vicinity of the Great-Boundary fault, Mathura fault, Moradabad fault.