Rural-urban water scarcity risks in historically water-abundant regions: The role of intensifying human-natural systems variability

The growing frequency and severity of extreme and compound events will pose unprecedented water scarcity challenges. These challenges are not only driven by changes in water resource availability, but also in water demands and quality, and can affect both arid and non-arid regions. As a consequence, trade-offs between rural and urban water uses across multiple sectors intensify. Behaviors, infrastructures, and institutions in many historically water-abundant regions are not adapted to efficiently allocate water under critical levels of scarcity. The resulting water scarcity risks so far receive insufficient attention. We integrate hydro-economic models in order to assess the potential for increasing trade-offs between rural and urban water use under socio-economic and climate change scenarios in a case study in Germany. We find that a multiplication in irrigation water demands in the relatively precipitation-scarce eastern part of the country threatens to compete with urban water consumption peaks under droughts and heat waves. Enhancing resilience for these water conflicts will require adaptation measures that equally account for human and natural scarcity drivers and that consistently consider the value of water across all rural and urban sectors.