Implementing the 3-30-300 Rule in Indian Cities: A Framework for Addressing Urban Challenges

The accelerating impacts of climate change, including escalating urban temperatures and the heightened occurrence of extreme weather events, present formidable challenges for rapidly growing cities, particularly in the Global South. Nature-based solutions (NBS) present transformative pathways to address these issues, offering sustainable approaches to enhance resilience, mitigate urban challenges, and improve the well-being of urban residents. Urban Green Spaces (UGSs) are central to these solutions, providing climate adaptation and mitigation benefits.

This study investigates the applicability of the 3–30–300 rule—a recently proposed guideline for equitable urban greening—through case studies in two Indian cities, Nagpur and Jaipur. The guideline advocates for three visible trees per residential building, 30% neighborhood UGS cover, and at least one hectare of UGSs within 300 meters of residences. A GIS-based analysis of land cover maps was conducted to assess public UGS availability, proximity, and provisioning gaps, addressing the 30-300 components. Household surveys measured the visibility of trees to evaluate the "three visible trees" component. A zone-specific analysis explored the potential of applying the 3–30–300 rule to mitigate challenges urban areas face, such as the Heat Island phenomenon and increased urban flooding—exacerbated by rapid urbanization and climate change.

This research develops a replicable and scalable methodological framework, enabling its application to other cities undergoing rapid urban transitions. By quantifying the benefits of equitable urban greening, the study provides urban planners and policymakers with actionable insights and tools for informed decision-making. Highlighting the potential of integrating NBS into mainstream urban planning, the study positions the 3–30–300 rule as a practical and effective guideline for addressing urban sustainability and resilience challenges, particularly in resource-constrained cities of the Global South.