Urban flooding widens inequalities in walking access to healthcare: geospatial modelling in Kampala, Uganda

Flooding is an increasing threat in rapidly growing cities, yet evidence on how heavy rainfall affects access to healthcare within cities and whether impacts are greater for vulnerable populations remains limited. This study quantifies how flooding changes walking access to healthcare in Kampala, Uganda, and how these changes are distributed across areas that differ in their population-level risk of undernutrition and poor maternal and child health outcomes. We conducted a cross-sectional ecological geospatial modelling study across Kampala and its whole population (approximately 1.8 million residents). We estimated walking travel time to the nearest public or private not-for-profit healthcare facility and hospitals under baseline and flood conditions. Flood scenarios were based on a hydrodynamic model simulating 15 rainfall events ranging from 20 to 100 mm over 1, 3, or 6 hours. Travel speeds accounted for caregivers walking with young children. Outcomes were population-weighted changes in travel time, summarised at parish level and compared across vulnerability groups. Here we show that flooding increases travel time across all scenarios, with larger effects for hospital access. Population-weighted mean increases in travel time range from 11.5 to 19.3 minutes for all facilities and from 23.4 to 56.3 minutes for hospitals across scenarios. In high-intensity storms, increases are greater in more vulnerable areas, particularly for hospital access, with largest disruptions in peripheral areas. Flooding reduces access to healthcare in Kampala and disproportionately affects more vulnerable populations. These findings show how extreme rainfall can widen inequalities in access to maternal and child health and nutrition services and support planning. Floods can make it harder for caregivers with young children to reach healthcare facilities. We studied Kampala, Uganda, to estimate how floods change walking time to healthcare. We combined maps of land, roads, water, and elevation with realistic walking speeds on wet surfaces and tested fifteen flood situations, from lighter, longer storms to intense, short ones. Here we show that travel times increased in every case: by about 19 minutes on average to the nearest clinic and 56 minutes to the nearest hospital for the most intense one-hour storms. Delays were greatest in high-vulnerability neighbourhoods and outer areas, while central areas changed less. These results can guide service placement. Lubbers et al. conduct a cross-sectional geospatial modelling study across Kampala to estimate how heavy rainfall affects healthcare access. They show that flooding reduces access to healthcare and disproportionately affects more vulnerable populations, resulting in widened inequalities.