Seismic Risk Assessment of Nagpur City using the Geographic Information System

Abstract

Earthquakes are the major threat to mankind accounting for almost half of the fatalities brought about by all of the natural hazards and desert their traces in societies for years. It is well known that seismic risk cannot be eliminated but minimized. Risk studies lay down the roadmap to prepare and minimize the aftermath of any disastrous event. Geographic Information System (GIS) has been proved as an effectual tool for seismic risk assessment study. This study presents the seismic risk assessment of Nagpur city using the GIS framework. Albeit per Indian Standard (IS) 1893-2016 [1] seismic zonation of Nagpur city comes under zone II (relatively low seismic hazard zone), the seismic risk being a combination of hazard, elements at risk and, vulnerability cannot be denied. Similar to other Indian cities the city of Nagpur had a heterogeneous development pattern. Even though Nagpur city is municipalized in well distributed wards, many intra wards distributions show housing clusters of different socioeconomic status. Therefore, using the satellite imagery different socioeconomic housing clusters were identified and mapped in the ArcGIS platform. Six socioeconomic clusters were identified using satellite imagery for Nagpur. From the field survey of randomly selected typical clusters, 14 prevailing Model Building Types (MBTs) were identified. Census data were used to find the population density and its distribution throughout the city. Seismic hazard has been estimated from IS 1893-2016 [1] as well as using the probabilistic hazard map of NDMA [2]. Selected MBTs were assessed for their seismic vulnerability, seismic risk in terms of casualties and damage is calculated. Finally, thematic maps showing damages arrived from the various approach are shown and discussed.