A proof of concept for rapid evaluation of urban climate adaptations using simplified simulations over an Indian city

Abstract

The 2024 Indian heatwaves highlighted the vulnerability of urban populations to extreme temperatures and related health risks. Current urban climate modeling practices, aimed at informing on the expected impacts of climate-sensitive designs, often rely on complex, high-resolution simulations that are time-consuming and resource-intensive. These “real-case” scenarios, while valuable, may also not explore the full range of adaptive options available to cities. We therefore propose to use simpler, more efficient modeling approaches using “idealized” scenarios to inform early-stage decision-making, especially during research and design phases. We demonstrate this by running 100 simulations per common urban climate intervention – including cool roofs, urban greening, or air conditioning – using the WRF BEP-BEM urban climate model. Focusing on the city of Bhubaneswar, in Odisha, India, we quantify how incremental one-percentage-point changes in each intervention may affect local temperatures and surface energy balance during the hottest-ever recorded day, and the warmest day of 2024 following the wet monsoon period. We then compare outcomes from idealized simulations with a selection of real-case scenarios based on modelled temperature changes to see if idealized simulations outputs are reliable. We show that idealized simulations can deliver clear, actionable insights on how common urban climate interventions can impact the local climate, useful for planners and designers. Limitations from simple two-dimensional simulations are also identified suggesting that our methods should be seen as a first actionable tool for identifying viable adaptation paths that will require further three-dimensional realistic simulations to estimate the expected impacts with greater certainty.