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פותח על ידי קלירמאש פתרונות בע"מ -
Impact of ambient temperature on evaporation from surface-exposed fractures
Year:
2009
Source of publication :
Water Resources Research
Authors :
קמאי, תמיר
;
.
Volume :
45
Co-Authors:
Facilitators :
From page:
To page:
(
Total pages:
1
)
Abstract:
Surface-exposed fractures (SEFs) form a unique link between the atmosphere and the deep vadose zone. Quantifying evaporation and salt-accumulation rates within these SEFs is essential for understanding processes leading to groundwater salinization and contamination via these fractures. In this study, evaporation from SEFs (ESEFs) was quantified, mainly as a function of ambient atmospheric temperature, by using large-scale laboratory experiments and measuring evaporation under controlled conditions. In addition, ESEF was theoretically quantified based on the physical processes that govern it. The theoretical model was used to analyze ESEF rates as a function of ambient temperature, temperature gradient, fracture-aperture, and matrix pore size. ESEF was experimentally found to increase as the ambient temperature decreased. Measured evaporation rates were between about 110 and 260 g d-1 per square meter of fracture surface, for temperature differences between rock-bottom and the atmosphere of 0° and 13°C, respectively. Comparing these values with model results suggests that convection is the driving process for enhanced evaporation at low ambient temperatures. Finally, we show that ESEF rates decrease as a result of salt precipitation. During a ∼9-month period, with an imposed temperature difference of 13°C, ESEF decreased from ∼260 to ∼95 g d-1 m-2 due to salt accumulation near and on the fracture surfaces. Evaporation rates began decreasing after about 100 g m-2 of salt had precipitated and decreased to less than 50% of the initial rate after 160 g m-2 of salt had precipitated. We thus show that not only temperature, but also salt precipitation, largely affect ESEF rates. Copyright 2009 by the American Geophysical Union.
Note:
Related Files :
Controlled conditions
groundwater
hydrogeology
Matrix pores
vadose zone
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More details
DOI :
https://www.scopus.com/inward/record.uri?eid=2-s2.0-62949157963&doi=10.1029%2f2008WR007354&partnerID=40&md5=ead85d1308a880f6abf1ec90f0645b45
Article number:
Affiliations:
Database:
סקופוס
Publication Type:
מאמר
;
.
Language:
אנגלית
Editors' remarks:
ID:
28656
Last updated date:
02/03/2022 17:27
Creation date:
17/04/2018 00:40
Scientific Publication
Impact of ambient temperature on evaporation from surface-exposed fractures
45
Impact of ambient temperature on evaporation from surface-exposed fractures
Surface-exposed fractures (SEFs) form a unique link between the atmosphere and the deep vadose zone. Quantifying evaporation and salt-accumulation rates within these SEFs is essential for understanding processes leading to groundwater salinization and contamination via these fractures. In this study, evaporation from SEFs (ESEFs) was quantified, mainly as a function of ambient atmospheric temperature, by using large-scale laboratory experiments and measuring evaporation under controlled conditions. In addition, ESEF was theoretically quantified based on the physical processes that govern it. The theoretical model was used to analyze ESEF rates as a function of ambient temperature, temperature gradient, fracture-aperture, and matrix pore size. ESEF was experimentally found to increase as the ambient temperature decreased. Measured evaporation rates were between about 110 and 260 g d-1 per square meter of fracture surface, for temperature differences between rock-bottom and the atmosphere of 0° and 13°C, respectively. Comparing these values with model results suggests that convection is the driving process for enhanced evaporation at low ambient temperatures. Finally, we show that ESEF rates decrease as a result of salt precipitation. During a ∼9-month period, with an imposed temperature difference of 13°C, ESEF decreased from ∼260 to ∼95 g d-1 m-2 due to salt accumulation near and on the fracture surfaces. Evaporation rates began decreasing after about 100 g m-2 of salt had precipitated and decreased to less than 50% of the initial rate after 160 g m-2 of salt had precipitated. We thus show that not only temperature, but also salt precipitation, largely affect ESEF rates. Copyright 2009 by the American Geophysical Union.
Scientific Publication
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