Seismic hazard and risk assessment for Delhi-NCT considering future earthquakes along two major active faults: Strategic planning for disaster risk reduction

Delhi-National Capital Territory (NCT) is crucial due to the complex tectonics, varying sedimentary thickness, vicinity of active faults, and high population density. The Mahendragarh- Dehradun Fault (MDF) and Delhi-Sargodha Ridge Fault (DSRF) are the prominent tectonic features in the Delhi-NCT, which have produced a maximum moment magnitude of Mw=5.2 in the past. An integrated study comprising seismic hazard modeling (along these two prominent active faults), site amplification, empirical vulnerability functions, and geospatial building inventory data in the Delhi-NCT region, has been conducted to propose the possible damage potential ratio, aiding disaster preparedness and risk mitigation. The seismic hazard has been estimated using stochastic finite fault modeling technique, considering moderate earthquake along multiple ruptures along MDF and DSRF, respectively, incorporating the parametric uncertainty. The maximum peak ground acceleration (PGA) of the order of 415.36 cm/sec2 at Rohtak (Haryana) and 384.03 cm/sec2 at Sonipat have been calculated due to a moderate earthquake along DSRF and MDF, respectively. The PGA due to the earthquake along the reverse fault (DSRF) is found to be higher than the PGA along the normal fault (MDF). The damage potential of 16 major areas has been estimated using PGA and vulnerability function, for the year 2025 on the basis of the linear projection using the census data by Government of India for the year 2000 and 2011, estimating ~ 8.9 million buildings. A total of 38% of buildings are found vulnerable to the moderate scenario earthquake along MDF and DSRF. The highest building damage potential is observed at Rohtak (~ 64%), lowest at Gurugram, Haryana (~ 20%).