Kiribati and Tuvalu, with fragile atoll environments, are particularly prone to environmental hazards as high population densities impact water supply systems, sanitation and solid waste management (see Chapter 8). These vulnerabilities will make it difficult for these countries to achieve Target 11.5 (reduce the impact of disasters). This will place immense pressure on already precarious situations in the urban centres, particularly in terms of access to adequate, safe and affordable housing and basic services (see Chapter 8), including transport.