Title: An Insight into Dew Potential Yield in Iran based on Long-Term Model Simulations and Cluster Analysis

Abstract:

Fresh water scarcity and continuously increased demand is one of the biggest problems in many locations on the globe, especially in arid and semi-arid regions. Dew is one of the precise natural phenomena that can be used as a secondary or complementary source of water in arid and semi- arid conditions such as Iran. In this study, we tried to estimate the potential of dew formation in Iran by utilizing a long- term (1979–2018) model simulation on a 1 m2 condenser. The results indicated that in almost all areas in Iran, the climatological conditions favour the formation of dew on condenser during the year. Seasonal analysis of dew yield indicated that in wintertime, frequency of dew occurrence, in most areas of Iran, is more than 80% days with the is highest amount of yield in the coasts of Persian Gulf (i.e. ~ 10 mm/ month). The occurrence of dew was rather similar during spring and autumn with more than 60% of the days, mostly in the mountain and coastal areas and less than 40% of days in dry interior and eastern areas. In warm seasons, although, in most of the areas the occurrence of dew declined to less than 5% of days, but still the coasts of Caspian see in the north of Iran show a high potential in dew yield. In order to determine the major dew yield zones in Iran we applied cluster analysis on the output of model simulation on the land of Iran. Consequently, we identified 4 dew zones (i.e. Alborz region, Zagros region, desert region and coastal region) based on clustering of daily amount of dew yield. The mean daily dew yield for zones was 0.14, 0.08, 0.04, and 0.09 mm/day; respectively. Seems that the dew formation zones in Iran are highly matched to the topography and sources of moisture. As our results show, the mountains and seas are playing a major role in distribution of dew formation regions.

Although Based on 40 years model simulation the total volume of dew yield can be collected on 1 m2 condenser in some dew events was not significant in some dry areas, but some water-stressed areas such as coasts of Persian Gulf and Oman Sea show potential for large-scale dew harvesting. Nevertheless, dew is worth to be investigated as a renewable source of water along with other resources in water management plans in a dry and dehydration country such Iran.

Biography:

Nahid Atashi is currently a PhD student in Synoptic Climatology in Department of Physical Geography, University of Isfahan, Iran. She did her bachelor study in physical geography in Beheshti university, Tehran, in 2011 and her master in synoptic climatology in University of Isfahan, in 2013. Her thesis title is “Estimates of dew collection potential in Iran as a secondary or complementary renewable source of water in arid and semi- arid environments”. Since August 2018, she has been a visiting PhD student at the Institute for Atmospheric and Earth System Research (INAR/Physics), University of Helsinki, Finland. Her research interests are Atmospheric Modelling, Climate change, New water resources. Nahid has 8 refereed publications.