Gas exchange rates for a first-order stream determined with deliberate and natural tracers

Gas transfer velocities have been determined for a first-order stream by performing a 3-hour release of the volatile tracer sulfur hexafluoride, SF6, and the nonvolatile tracer tritiated water, 3H2O. The average gas transfer velocity for the 292-m reach was 29 cm/h which corresponds to a reaeration...

Full description

Saved in:
Bibliographic Details
Published in:Water resources research 1990-07, Vol.26 (7), p.1621-1630
Main Authors: Wanninkhof, R. (Columbia University, Palisades, NY), Mulholland, P.J, Elwood, J.W
Format: Article
Language:English
Subjects:
AERACION
AERATION
AGUAS SUBTERRANEAS
COURS D'EAU
CURSOS DE AGUA
EAU SOUTERRAINE
ELEMENT CHIMIQUE
ELEMENTOS QUIMICOS
GASES
GAZ
ISOTOPE RADIOACTIF
RADIOISOTOPOS
TECHNIQUE DES TRACEURS
TECNICAS DE AISLAMIENTO DE ISOTOPOS
TENNESSEE
VELOCIDAD
VITESSE
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Gas transfer velocities have been determined for a first-order stream by performing a 3-hour release of the volatile tracer sulfur hexafluoride, SF6, and the nonvolatile tracer tritiated water, 3H2O. The average gas transfer velocity for the 292-m reach was 29 cm/h which corresponds to a reaeration coefficient for oxygen at 25 degrees C of 134 day-1. Groundwater inflow along the stream was corrected for by measuring the downstream dilution of the 3H2O spike. Downstream discharge increased from 0.5 L/s, 2 m downstream of the point of tracer release, to 19.3 L/s at a point 292 m downstream. As an alternative to using (radioactive) 3H2O, we investigated the possibility of using natural radon, 222Rn, as a groundwater tag and using the variation of SF6 and 222Rn along the stream to determine gas exchange rates and groundwater inflow. The method yielded an average transfer velocity of 21 cm/h and underestimated the groundwater inflow by a factor of 3. This large discrepancy is attributed to a doubling of stream discharge between the time the stream was sampled for radon and the tracer experiment and the limited number of radon samples
ISSN:0043-1397
1944-7973
DOI:10.1029/WR026i007p01621