Evaporation Dynamics and Water Resource Management

Evaporation is a central component of the terrestrial water cycle, governing the exchange of water between natural and engineered reservoirs and the atmosphere. Its rate is controlled by the energy balance at the water‐air interface, where incoming solar radiation and long‐wave fluxes are partitioned into latent heat flux, driving phase change, and sensible heat flux, influencing air temperature. The ratio of sensible to latent heat fluxes, known as the Bowen ratio, provides insight into the dominant energy pathway. Climatic drivers such as wind speed, humidity deficit, air temperature and surface area interact to determine evaporation rates, while seasonal and interannual variability modulate long‐term water budgets. Accurate quantification of evaporative losses is indispensable for sustainable water resource management, especially in arid and semi‐arid regions where storage efficiency of reservoirs and small water bodies is critical. Advances in remote sensing, physically based modelling and in situ measurements have enhanced our capacity to estimate evaporation at scales from individual farm dams to millions of global lakes. These developments underpin practical applications including reservoir operation, irrigation scheduling, evaporation suppression measures and transboundary water allocations, thereby strengthening resilience to drought and climate change.

Research from Nature Portfolio

Recent studies have combined long‐term satellite observations with hydrodynamic and energy‐balance models to quantify evaporation volumes from natural and artificial lakes worldwide. Analysis of 1.42 million lakes over more than three decades reveals an average annual evaporation volume of 1 500 ± 150 km3, with a rising trend of approximately 3.1 km3 yr−1. In attributing this increase, enhanced evaporation rates contribute over half of the trend, reduced ice cover about a quarter, and expanding lake surface area the remainder. Although artificial reservoirs comprise only 5 % of global lake storage, they account for 16 % of evaporative volume, highlighting their disproportionate role in water‐budget assessments. Such findings underscore the need to consider evaporation volume—rather than rate alone—as a primary index for evaluating hydrological impacts of climate variability and reservoir management strategies.

Evaporation Dynamics and Water Resource Management publication trend

The graph below shows the total number of articles in evaporation dynamics and water resource management across all publications each year (not limited to Nature Index journals).

Technical terms

Latent heat flux: The energy flux associated with phase change of water from liquid to vapour at the surface.

Bowen ratio: The ratio of sensible heat flux to latent heat flux, indicating the partitioning of available energy.

Evaporation volume: The total volume of water lost through evaporation over a defined water body and time period.

Potential evaporation: The theoretical maximum evaporation rate under unlimited water supply and specified atmospheric conditions.

Remote sensing: The acquisition of data about Earth’s surface by satellite or airborne sensors, used to infer surface temperature, area and ice cover for evaporation estimates.

References

1. Quantifying water evaporation from large reservoirs: Implications for water management in water-stressed regions. Environmental Research (2024).
2. Shading solutions for sustainable water management: impact of colors and intensities on evaporation and water quality. Applied Water Science (2024).
3. Evaporative water loss of 1.42 million global lakes. Nature Communications (2022).