Health impacts are critical yet often overlooked. Given subsidence is associated with flooding, chronic flooding increases the risk of waterborne diseases (e.g. diarrhoeal diseases) and vector- borne diseases (e.g. malaria).25,26 Prolonged exposure to damp environments can lead to respiratory illnesses, particularly among vulnerable populations.27 Flooding can also bring harmful chemicals from underground to the surface, posing toxicological risks.28 Beyond physical health, persistent threats of flooding, displacement and property loss can impact mental health. There is a strong correlation between a healthy environment and a healthy population, as highlighted in frameworks such as DIALOG’s Community Wellbeing Framework.29 It recognizes that without meaningful community engagement, efforts to promote well-being are less likely to succeed. Flooding and related risks also disproportionately affect women and children, especially in places where water accessibility is limited and inequitable. In some countries, these risks can reduce women’s participation in household decision- making. For children, these conditions can result in reduced school attendance and an increased risk of child marriage.30,31 The 1.1 billion residents of informal settlements and slums also face heightened risks. These communities are often located in high-risk, low- lying areas and face additional vulnerabilities due to inadequate housing, limited access to basic services and insecure tenure. As a result, they bear the brunt of urban disasters yet remain largely invisible in resilience planning and investment. Furthermore, strong social networks and a resilient social fabric are essential for building community resilience to both acute and chronic shocks (e.g. subsidence and flooding). Community facilities, public spaces, local governance and social agencies all play a vital role in helping communities adapt and recover more effectively. There is growing recognition of the broader influence of social determinants of health (e.g. housing, income, physical environment and healthcare access). The risks of land subsidence, compounded by climate risks, can undermine these determinants and create public health challenges, ultimately affecting well-being and economic productivity. Strong social networks and a resilient social fabric are essential for building community resilience to both acute and chronic shocks. Resilient Economies: Strategies for Sinking Cities and Flood Risks 8

Resilient Economies Strategies for Sinking Cities and Flood Risks 2025