Dew Formation and Water Resource Management in Arid Environments

In arid and semi-arid regions, dew formation represents a critical, yet often overlooked, component of the hydrological cycle. Dew arises when surfaces lose heat by long-wave radiation during clear, calm nights, causing their temperature to fall below the ambient dew point and inducing condensation of water vapour. The yield and frequency of dew depend on factors such as surface emissivity, wind speed, relative humidity and the thermal properties of soils and vegetation. In desert and dryland ecosystems, dew can contribute between 5% and 15% of total non-rainfall water inputs, helping to sustain microbial activity, mitigate plant water stress and support soil moisture during extended dry spells. Technological advances in passive dew-harvesting materials, ranging from specialised polymer foils to bio-inspired radiative panels, have demonstrated potential yields of tens to hundreds of litres per square metre per year in coastal and high-latitude deserts. Integrating dew collection into broader water resource management offers a decentralised supplementary supply for livestock, crop irrigation and community needs, particularly in regions where conventional sources are scarce. Modelling studies reveal that dew yields are sensitive to climate variability and land-use change, with warming trends and altered humidity regimes likely to affect dew frequency and volume. Effective management strategies therefore combine accurate microclimatic monitoring, surface engineering, and ecosystem assessments to maximise dew capture, enhance soil water retention and sustain vegetation cover, contributing to both ecological resilience and human water security in drylands worldwide.

Research from Nature Portfolio

Recent studies have quantified the significance of atmospheric vapour adsorption onto soil particles as a substantial source of liquid water during rain-free periods. Controlled experiments using isotopically labelled water vapour demonstrated that vapour adsorption can rapidly increase surface soil moisture across temperature ranges typical of arid ecosystems, with direct stimulation of microbial carbon cycling. Field observations in semi-arid grassland confirmed that non-rainfall water inputs from vapour adsorption rival or exceed dewfall in frequency and that this process exerts a stronger influence on soil biogeochemical activity than temperature fluctuations. These findings underscore the need to incorporate vapour adsorption into ecohydrological models and to recognise this mechanism as a complementary water source in dryland management.

Dew Formation and Water Resource Management in Arid Environments publication trend

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

Technical terms

Dew point: the air temperature at which water vapour begins to condense into liquid on a surface.

Water vapour adsorption: the process by which atmospheric water vapour adheres to soil particles, forming liquid water.

Non-rainfall water (NRW): all atmospheric water inputs excluding rainfall, such as dew, fog, frost and adsorption.

Micro-lysimeter: a small weighing device designed to measure minute changes in water mass in soil or vegetation plots.

Evapotranspiration: the combined loss of water from land surfaces through evaporation and plant transpiration.

Relative humidity: the ratio of current atmospheric moisture to the maximum moisture capacity at a given temperature, expressed as a percentage.

References

1. Water from air: an overlooked source of moisture in arid and semiarid regions. Scientific Reports (2015).
2. Estimates of global dew collection potential on artificial surfaces. Hydrology and Earth System Sciences (2015).
3. Evaluation of the physiological significance of leaf wetting by dew as a supplemental water resource in semi-arid crop production. Agricultural Water Management (2021).
4. Technical note: High-accuracy weighing micro-lysimeter system for long-term measurements of non-rainfall water inputs to grasslands. Hydrology and Earth System Sciences (2022).
5. Modeling Long-Term Temporal Variation of Dew Formation in Jordan and Its Link to Climate Change. Water (2020).