Unveiling socio-economic inequity in local-scale compound flood risks in Indian coastal city

Abstract

The warming climate has increased the frequency and intensity of floods in urban areas globally. The accelerating populace, coupled with rapid urbanization, amplifies the impact of floods that strain local communities. Existing disparities of unequal exposure to floods in vulnerable communities further burden post-disaster recovery, necessitating comprehensive urban-scale risk assessments. In this study, we quantify this unequal exposure by integrating flood hazards induced by stream flow, rainfall, and storm tides with the measure of socio-economic disadvantage. A 3-way coupled hydrodynamic model has been developed on the MIKE+ over the flood-prone city of Kozhikode, integrating the influence of stormwater drains, tide, and flow through the channel to generate flood hazard scenarios. Socio-economic vulnerability is quantified using a nonparametric data envelopment analysis that accounts for demographic indicators. The initial assessment reveals a disparity in flood exposure, with socially vulnerable populations in Kozhikode bearing a disproportionately higher burden, exacerbating challenges for less resilient communities. The results from the application of the Lorenz curve at the ward level further emphasize the inequitable distribution of flood risk. Our study provides valuable insights into the nuanced dynamics of different drivers of floods and their impact on communities for formulating targeted planning and adaptation strategies for reducing flood risk equitably and sustainable urban resilience.