Reimagining Nashik Kumbh Mela through a theory of change lens: A systems approach to public health, crowd risk, and river sustainability

Mass gatherings such as the Kumbh Mela in Nashik generate interlinked risks of infectious disease, crowd safety, hygiene, and degradation of river ecosystems. This mini-review proposes a theory of change framework that integrates public health surveillance, crowd management, water systems and environmental protection into a single system-based approach. Drawing on evidence from the Kumbh Mela , the Hajj and other mega-conventions, the present study highlights how the dynamics of behaviour, mobility patterns and governance structures shape health and environmental outcomes. The proposed framework identifies the causal links linking surveillance, crowd flow management and river health interventions to measurable improvements in human and environmental well-being. This study explores whether the Nashik Kumbh Mela can serve as a worldwide model for results-oriented and environmentally conscious collective management.