Climate Impact on Hydrological Variability

Hydrological variability refers to fluctuations in the movement, distribution and quality of water within the terrestrial environment. Climate change has altered precipitation patterns, snow dynamics and evaporation rates, while rising temperatures intensify evapotranspiration and shift seasonal runoff regimes. These modifications affect water availability for ecosystems, agriculture and urban supplies, and exacerbate the frequency and severity of droughts and floods. At catchment scale, interactions among soil, vegetation and climate determine how incoming water is partitioned between surface runoff, groundwater recharge and atmospheric return. Frameworks such as that proposed by Budyko enable researchers to disentangle the influence of changing energy and moisture inputs from landscape characteristics. Understanding these processes is essential for managing reservoirs, designing infrastructure resilient to extremes and securing freshwater resources under a warming world.

Research from Nature Portfolio

Quantitative analyses of large basins have illuminated the relative roles of climate and human activity in altering streamflow. One study of the Tarim River Basin employed double‐mass curve methods alongside a modified Budyko approach to show that agricultural expansion, irrigation withdrawal and land‐cover change accounted for more than 100 % of observed reductions in river discharge during key post‐development periods, with climatic factors contributing a secondary yet increasing share. On a continental scale, an investigation across Canadian watersheds used elasticity analysis within the Budyko framework to separate climate‐driven gains in mean annual streamflow from human‐induced declines linked to land‐use change and water abstraction. The work highlighted that, although retreating glaciers have cushioned some losses, the cumulative impact of anthropogenic alterations has driven a net reduction in runoff, underscoring the urgency of integrated water management strategies.

Climate Impact on Hydrological Variability publication trend

The graph below shows the total number of articles in climate impact on hydrological variability across all publications each year (not limited to Nature Index journals).

Technical terms

Hydrological variability: The range and pattern of change in water fluxes and storages within a watershed over time.

Runoff: The portion of precipitation that flows over land or through subsurface pathways into streams, rivers and lakes.

Evapotranspiration: Combined loss of water to the atmosphere by evaporation from soil and water surfaces and by plant transpiration.

Aridity index: A dimensionless ratio of potential evapotranspiration to precipitation indicating climatic dryness.

Budyko framework: A conceptual model relating long-term water balance partitioning to the balance of water and energy inputs at catchment scale.

References

1. Climate-vegetation-soil interactions and long-term hydrologic partitioning: signatures of catchment co-evolution. Hydrology and Earth System Sciences (2013).
2. Identification of potential impacts of climate change and anthropogenic activities on streamflow alterations in the Tarim River Basin, China. Scientific Reports (2017).
3. Contribution of human and climate change impacts to changes in streamflow of Canada. Scientific Reports (2015).
4. Reduced Runoff in the Upper Yangtze River Due To Comparable Contribution of Anthropogenic and Climate Changes. Earth's Future (2024).
5. Changing forest water yields in response to climate warming: results from long‐term experimental watershed sites across North America. Global Change Biology (2014).