Dew, fog, and rain as supplementary sources of water in south-western Morocco

I. Lekouch (1, 2, 3) , Marc Muselli (2, 4) , B. Kabbachi (3) , Jalil Ouazzani (2, 5) , Iryna Melnytchouk-Milimouk (2, 5) , Daniel Null Beysens (1, 2, 6)

1 PMMH - Physique et mécanique des milieux hétérogenes (UMR 7636)
2 International Organization for Dew Utilization
3 Université Ibn Zohr [Agadir]
4 SPE - Sciences pour l'environnement
5 Arcofluid
6 SBT - Service des Basses Températures

This study reports on one year (May 1, 2007 - April 30, 2008) of dew, fog and rain measurements carried out in the dryland area of Mirleft, Morocco in order to be used as alternative or supplemental sources of water. Four standard dew condensers and a passive fog net collector of 1 m² surfaces were used. Meteorological data were collected. 178 dew events (18.85 mm), 31 rain events (48.65 mm) and 7 significant fog episodes (1.41 mm) occurred, corresponding to almost 40% of the yearly rain contribution (48.65 mm, 31 events). Chemical and biological analyses were carried out. Dew and rain pH were neutral (close to 7) and the total mineralization was considerable (dew: 560 mg/L; rain: 230 mg/L). Ca²+, K+, SO42- and NO3- are found of continental origin; Cl-, Na+ and Mg2+ are of sea origin. The ions concentration agrees with the World Health Organization recommendations for potable water. The biological analysis shows harmless vegetal spores and little contamination by animal/human bacteria. A cost analysis shows that, with little investment, the population of the arid and semi-arid coastal areas of south-western north Africa could make dew water an interesting supplementary alternative water resource.

Domaines: Physique Générale [physics.gen-ph]

I. Lekouch, Marc Muselli, B. Kabbachi, Jalil Ouazzani, Iryna Melnytchouk-Milimouk, et al.. Dew, fog, and rain as supplementary sources of water in south-western Morocco. Energy, 2011, 36 (4), pp.2257-2265. ⟨10.1016/j.energy.2010.03.017⟩. ⟨hal-00590605⟩