Vannstress

Vannstress, or water stress, is the condition in which freshwater resources are under sustained pressure due to a combination of natural variability and human demands. It occurs when supply is insufficient to meet human needs and maintain ecosystem health over time, often reflected in high water withdrawals, shrinking per capita availability, groundwater depletion, or deteriorating water quality. Drought can contribute, but water stress emphasizes persistent pressure rather than a single dry spell.

Causes and drivers include rapid population growth, urbanization, and the predominance of irrigation in agriculture; climate change increasing the frequency and severity of droughts; pollution and degradation of water quality; and geopolitical or transboundary factors that complicate cooperation over shared resources.

Indicators used to assess vannstress include the withdrawal-to-availability ratio, per capita renewable freshwater, groundwater level trends, reservoir storage, and water quality indicators. International bodies also look at the risk of deficits during dry seasons and the resilience of water infrastructure.

Impacts can include reduced agricultural output and food security, higher costs for households and industry, increased energy demand for treatment and pumping, and potential ecological losses. Social tensions and health risks may arise where water supply is unreliable.

Management and mitigation focus on improving efficiency, particularly in irrigation; pricing and governance that reflect water scarcity; reducing leaks and losses in distribution; reusing treated wastewater; expanding desalination in suitable regions; rainwater harvesting; and cooperative transboundary water management.