LIVING ON THE EDGE: ASSESSING INFRASTRUCTURE VULNERABILITIES FROM SINKING AND SLIDING OF A POPULATED HIMALAYAN SLOPE

Increased anthropogenic activities combined with the extremes of a changing climate can destabilize mountain slopes, putting both people and infrastructure at grave failure risk to creeping motions and rendering the existing structures unsuitable for habitation. Slow-moving landslides are primarily characterized by their horizontal movements, whereas rapid sinking is less frequent. In this context, Joshimath, a famous pilgrimage Himalayan slope town with over 20,000 inhabitants and 10,000 structures, provides a dramatic example for the possible consequences on surface deformation on a densely populated settlement area. In 2023, Joshimath has experienced sudden subsidence, and horizontal creep that significantly impacted numerous infrastructures. Dynamics of such populated slopes and their impact on the structural health of the infrastructures have not been well studied so far. Here, we examine the infrastructure vulnerabilities of Joshimath based on satellite radar images sensed over a decade between 2014 and 2023. We observed a maximum subsidence of 2.9 cm/yr and eastward motion of 2.6 cm/yr. Based on these surface deformations, we identified structures exposed to very high (358 structures) and high (1,280 structures) damage hazard caused by angular distortion and horizontal strain. Our research can better assist policymakers in developing robust resilience and mitigation strategies to address the structural vulnerabilities of buildings in the widely visited pilgrimage town.