Study of dew water collection in humid tropical islands

Dew has broad relevance to physical geography and many human activities. This paper reviews the observation and simulation of rural and urban dew, and the implications of dew as a climatic phenomenon. There is no universal protocol for measuring dew (i.e., condensation on cooled surfaces), its component fluxes (dewfall and distillation) or guttation, which is ‘dewdrops’ exuded from leaves. The many methods that exist to measure dew and surface moisture range from simple visual assessment, to electronic wetness sensors, lysimetry and remote sensing. Most studies of dew are rural; urban dew data are rare and studies seldom address dew in patchy landscapes, e.g., a forest clearing. Hardware dew models are rare. Numerous numerical models exist to simulate or forecast dew on rural crops but few address dew for surfaces other than leaves, e.g., a cocoa pod or road. There is a general consensus in the literature that dew is reduced or absent in cities because of the urban heat island effect and reduced vapour su...

Observation and simulation of dew in rural and urban environments

Sensitivity of simulated dew duration to meteorological variations in different climatic regions of California

Measurements and ecological implications of non-rainfall water in desert ecosystems—A review

The temporal dynamics of dew formation in cold desert-shrub ecosystems are still poorly understood. We examined dew and its abiotic controls in a shrubland in northwestern China with continuous eddy-covariance measurements of latent heat fluxes gathered over the growing-season of 2012. The dew amount was larger in mid-summer than in spring and autumn, but the dew duration was shorter in summer (from ~10:00 p.m. to ~6:30 a.m.) than in spring and autumn (from ~8:30 p.m. to ~7:30 a.m.). Dew occurred on 85% (166 days) of growing-season days, with monthly means ranging from 0.09 to 0.16 mm day−1. Dew was dominantly and positively controlled by Relative Humidity (RH), which explained 89% of its variation. Soil heat flux (G), air temperature (Ta), wind speed (Ws), Soil Water Content (SWC) and Vapor Pressure Deficit (VPD) also influenced dew formation. The most favorable conditions for dew formation were at Ta 75%. The Penman–Monteith equation predicted actual dew reasonably well. The predicted growing-season dew amount (21.3 mm) was equivalent to 7.2% and 8.9% of corresponding rainfall and evapotranspiration, respectively. It is suggested that dew could be a stable and continuous source of water that helps desert plants survive during warm summers.

Dynamics of Dew in a Cold Desert-Shrub Ecosystem and Its Abiotic Controls

This study presents the results of an analysis of the dewfall features of a tropical station. The importance of dewfall cannot be overemphasized, especially during the dry season when plants are under seriously stress. A positive correlation was found between dewfall and rainfall. Dew formation was found to peak on a diurnal basis between 6 a.m. to 8 a.m., suggesting that some steering mechanism is required for dew formation at this station. Dew formation starts later at night during the dry season but much earlier during the rainy season. The August anomaly already highlighted by Ireland showed up in dew formation as there was a marked reduction in dew formation in that month.

Dewfall features of a tropical station: The case of Onne (Port Hartcourt), Nigeria

This is a temporal and comparative analysis of thunderstorms and some related phenomena in three towns in the northern part of Nigeria.

O. A. Salau

Papers

Dewfall features of a tropical station: The case of Onne (Port Hartcourt), Nigeria

Temporal and comparative analysis of thunderstorms and some related phenomena in Zaria, Jos, and Kaduna (Nigeria)