Recent and future exposure of water, sanitation, and hygiene systems to climate-related hazards in Zambia

Climate change-driven water scarcity will lead to inequitable water, sanitation, and hygiene (WASH) access. However, current research in Zambia has ignored linking climate science dimensions to WASH access programs, thus limiting WASH-related climate action across the country. Here, we combine analyses of in situ datasets, modeling techniques, and systematic literature reviews to provide a solid climate science basis for WASH-climate action in Zambia. We find that in a warm near future climate, the stretch along the Copperbelt-Livingstone railroad from the north to the south of the country is expected to record an increase in heavy rainfall single-day events ranging between 50 and >= 150 mm. As such, bacterial diseases, such as cholera outbreaks, are expected to increase, especially in the Copperbelt, Central, Lusaka, Southern, and the Eastern Provinces. Models further predict a drier Zambia in the near and far future of up to 12 days year(-1), suggesting a higher risk of increased aridity which will compound challenges to the provision of safe drinking water. The projected rapid population growth in these regions will also heighten the challenges of accessing safe drinking water. Strategic investments in enhancing WASH access in these areas should be considered a matter of urgency.