• Multi-criteria approach using GIS for macro-level seismic hazard assessment of Kachchh Rift Basin, Gujarat, western India – First step towards earthquake disaster mitigation

• # Fulltext

https://www.ias.ac.in/article/fulltext/jess/131/0003

• # Keywords

Intraplate; Kachchh Rift Basin; seismic hazard assessment; geographical information system.

• # Abstract

The earthquakes have the most dominating societal and economic impact on the built environment. The earthquakes in an intraplate region are infrequent but often damaging. The uncontrolled urban growth in cities due to population explosion and migration makes it necessary to assess seismic hazards in an active region. It provides parameters for seismic safety and helps in disaster mitigation. The Kachchh Rift Basin (KRB) of western India is a seismically active intraplate region where many damaging earthquakes have occurred in the past (Mw 7.8 in 1819, Mw 7.6 in 2001). The KRB hosts many economic corridors and ports. Though the region has been put in a category with highest seismic hazard, the entire region is not prone to high hazards. The primary objective of the study is to integrate major attributes that influence seismic hazard on a GIS platform and prepare a multi-criteria-based hazard map by multi-criteria decision process named as analytical hierarchy process (AHP) developed by Saaty. In this study, the information about some of the attributes like peak ground acceleration (PGA), geology and geomorphology, and tsunami hazard is taken from published literature, whereas shear wave velocity to 30 m depth (Vs)$_{30}$ and amplification factor were obtained through empirical relationships. The integration of these different attributes was performed, and weights were assigned depending on their contribution to the seismic hazard. The multi-criteria approach reveals that the southwestern part comprising of Kachchh mainland has a low hazard as compared to central and northern parts and almost 1 million people and around 0.18 million houses are exposed to moderate to high hazard. Large swaths of land are prone to liquefaction hazard. The corridor comprising of Bhuj, Bhachau and Rapar needs seismic microzonation. This macro level hazard map will be beneficial for the urban planners and government authorities to decide the areas, where seismic microzonation or site-specific studies are required that would help in mitigating earthquake disasters in the future.

• # Author Affiliations

1. Seismic Hazard and Microzonation Group, Institute of Seismological Research, Raisan, Gandhinagar, Gujarat, India.

• # Journal of Earth System Science

Volume 131, 2022
All articles
Continuous Article Publishing mode

• # Editorial Note on Continuous Article Publication

Posted on July 25, 2019