Food-energy-water sustainability in urban spaces: insights from open geospatial datasets in Coimbatore, India

Abstract The growing urban population and increasing climate anomalies pose persistent challenges to urban resilience by threatening food, water, and energy security and intensifying land-use competition. Utilizing urban rooftops for gardening, rainwater harvesting, and renewable energy systems offers a sustainable pathway to mitigate these pressures. This study develops a geospatial framework to evaluate the sustainable use of built-up areas in Coimbatore, India, using open-access geospatial datasets. Spatial and economic assessments were conducted to estimate the feasibility and revenue potential of rooftop gardening, rainwater harvesting, and photovoltaic installations. Our results reveal the economic potential of 368,748 rooftops in Coimbatore, with the projected revenue. Photovoltaic systems could generate ₹ 28.58 billion, while rooftop gardens and rainwater harvesting contribute ₹ 15.79 billion and ₹ 0.34 billion, respectively. Crop-specific analysis identified chillies as the most profitable rooftop crop, with a potential revenue of ₹ 38.51 billion, whereas coriander showed the lowest at ₹ 4.57 billion. These findings highlight the economic and environmental opportunities associated with rooftop agriculture and renewable energy systems, emphasizing their role in sustainable urban planning Open-access satellite imagery proved to be an invaluable tool in assessing the potential of rooftop spaces, offering valuable insights for urban planners and policymakers.