Seismic vulnerability assessment of earthquake-prone mega-city Shillong, India using geophysical mapping and remote sensing. Issue 2 (2nd April 2020)

• Record Type: Journal Article
• Authors: Baruah, Saurabh; Boruah, Goutam Kashyap; Sharma, Sangeeta; Hoque, Washim Akram; Chetia, Timangshu; Dey, Chandan; Gogoi, Devakrishna; Das, Papu Kumar; Baruah, Santanu; Basumatari, Dipak; Pathak, Jayanta; Barua, Anurup Gohain; Choudhury, Sailendra
• Is Part Of: Georisk. Volume 14:Issue 2(2020)
• Page Start: 112
• Page End: 127
• Publication Date: 2020-04-02
• Subjects: Seismic hazard and risk -- seismic vulnerability -- Shillong -- rapid visual screening; Environmental risk assessment -- Periodicals; Hazardous geographic environments -- Risk assessment -- Periodicals; Reliability (Engineering) -- Periodicals; Risk management -- Periodicals; 624.151
• DOI: 10.1080/17499518.2019.1598560
• Languages: English
• ISSNs: 1749-9518

Abstract

ABSTRACT: The concept of seismic vulnerability is a yard-stick of damage estimation from a probable earthquake considering physical cum social dimension and enables a basis for decision-makers to develop preparedness and mitigation strategies. We aim at vulnerability assessment of the typical urban system of capital city Shillong situated on hilly terrain. High-resolution satellite imagery of Shillong facilitates analysis of building footprints, communication network, and open ground. Different building typologies are identified taking into account the building's structural configuration assessed through a rapid visual survey of more than 15% of total residential households. Slope map demarcates the landslide-prone area through discrete elevation modelling. A methodology incorporating several parameters e.g. building typology, slope angle, shear wave velocity characteristics, geomorphology, and the number of occupants in correlation with a physical measurement of vulnerability is presented and is applied to estimate the dimension of vulnerability. Additionally, MASW survey indicates lithology up to 30 m deep along with the existence of stiff soil and rocks at different depths whereas resonant frequency is identified to be in the range of 6–8 Hz through H/V ratio. Integrating all, it is observed that more than 60% of Shillong city falls under moderate to higher vulnerability and the rest is less vulnerable.