Flood Vulnerability in Informal Settlements

A 2024 study published in Nature Cities reveals that over 158 million slum dwellers in India live in flood-prone zones, making it the most exposed country globally in terms of flood vulnerability in informal settlements.

Flood Risk, Informal Settlements, and Climate Justice in the Global South

1. Overview of Flood Risk and Global Exposure

• Global Picture: As per Moody’s 2024 report, over 3 billion people globally face flood-related hazards annually.
• India’s Exposure: Over 600 million Indians are vulnerable to inland and coastal flooding.

2. Findings of the 2024 Study in Nature Cities

• Scope of the Study
  • Analysed satellite imagery and matched with 343 large-scale floods.
  • Covered 129 low- and middle-income countries, focused on slum dwellings.
• Key Observations
  • India leads globally with 158+ million slum dwellers in floodplains.
  • Other countries with high exposure: Indonesia, Bangladesh, Pakistan, Brazil.
• 33% of informal settlements in the Global South have already experienced floods.

3. Regional Settlement Patterns and Vulnerabilities

• Regional Urbanisation Trends
  • Latin America and Caribbean: 80% urbanisation; most settlements urban.
  • Sub-Saharan Africa: Lowest urbanisation; 63% informal settlements rural.
  • India: 40% of slum dwellers are in urban/suburban settings.
• Drivers of Settlement in Floodplains
  • Economic pressures (affordable land, proximity to jobs).
  • Lack of urban planning and infrastructure.
  • Social marginalisation pushing migrants to risky zones.

4. Inequities in Flood Exposure and Impact

• Nature of Risk
  • Slum dwellers face higher vulnerability due to poor housing quality, lack of drainage, healthcare, and mobility.
• Wealthier vs. Poorer Regions
  • In rich nations: Floodplain living is subsidised and insured (e.g., beachfront homes).
  • In the Global South: Floodplain land is cheap, encouraging high-risk settlement.
• Urban Development Dynamics
  • Gentrification of low-lying areas pushes slum residents to more hazardous fringes.
  • Example: In Bengaluru, IT and real estate avoid flood-prone zones, leaving them for informal housing.

5. Data-Driven Governance Gaps

• 32% greater likelihood of informal settlements in floodplains than elsewhere.
• Current approaches rely on population-level planning, ignoring micro-vulnerabilities.
• Lack of disaggregated risk data leads to ineffective disaster preparedness.

6. SDG Implications and Human-Centric Planning

• This pattern threatens progress on SDGs 1 (No Poverty), 6 (Clean Water), 11 (Sustainable Cities), and 13 (Climate Action).
• Need to shift from location-based to human-centric flood adaptation strategies.
• Focus areas:
  • Inclusive infrastructure development
  • Skills in sanitation and waste management
  • Empowered local governance and participatory planning