Exploring the heterogeneity in relationship between heat exposure and land development in Mumbai, India: a framework to address urban vulnerability in developing megacities

Informal settlements in developing megacities are often vulnerable to extreme heat and other environmental hazards. Yet, understanding of this vulnerability remains limited due to inadequate attention to the relationships between characteristics of the built environment and land surface temperature. To address this, we focus on the Mumbai region and employ a Geographically Development-Weighted Regression model that can link land surface temperature with datasets that can capture key characteristics of the built environment, particularly formal or informal settlement types and infrastructure quality. We find the existence of spatial heterogeneity in these relationships suggesting that informal settlements are correlated with higher land surface temperatures, especially under low development conditions. We also find that this effect grows with settlement size, and that the growth in these settlements would increase land surface temperature. We conclude with some guidance for planners and policymakers.