Liquefaction vulnerability across seismic zones of India: A critical review of geohazard risk

This paper presents a comprehensive review of earthquake-induced soil liquefaction hazards across various regions of India, emphasizing their connection with major seismic geohazards. India, with a population of approximately 1.45 billion, is characterized by a diverse geological and geotectonic setup and heightened seismicity in the subcontinent, necessitating robust construction techniques for long-term preparedness and mitigation for any impending earthquakes. This study systematically compiles and evaluates liquefaction susceptibility across pan-India through different zones, including northern, southern, eastern, western, and north-eastern regions, in accordance with the four seismic zones of India. The data of standard penetration test (SPT) and cone penetration test (CPT) have been employed as the primary geotechnical methods to assess liquefaction potential, supported by geophysical tests and field observations. The factor of safety (FOS) was calculated to determine the severity of liquefaction susceptibility. In the north zone, areas like Srinagar show high liquefaction potential, especially near water bodies, while Chandigarh exhibits low susceptibility. The south zone's Chennai displays severe liquefaction risk along its eastern coastal parts, whereas south-western areas remain relatively safe. The east zone, particularly Bihar, is highly vulnerable, with districts like Darbhanga experiencing severe liquefaction due to frequent seismic activity. In the north-east zone, Guwahati, located in seismic zone V, shows high susceptibility, exacerbated by its proximity to the Brahmaputra River. The north-west zone's Kutch region in Gujarat is notably susceptible due to past seismic events and loose sandy soils, while urban areas like Mumbai show lower risk due to deeper bedrock conditions. Overall, Seismic Zone II, including regions in south and parts of the west zone, is identified as the safest, while seismic zone V, particularly in the northeast, north, and parts of the west, is most at risk. The findings underscore the urgency of assessing liquefaction as a critical seismic geohazard, necessitating robust soil testing, disaster-resilient infrastructure, and ground improvement techniques in vulnerable zones.