Titelangaben
Gleeson, Tom ; Manning, Andrew H. ; Popp, Andrea ; Zane, Matthew ; Clark, Jordan F.:
The suitability of using dissolved gases to determine groundwater discharge to high gradient streams.
In: Journal of Hydrology.
Bd. 557
(2018)
.
- S. 561-572.
ISSN 0022-1694
DOI: https://doi.org/10.1016/j.jhydrol.2017.12.022
Abstract
Determining groundwater discharge to streams using dissolved gases is known to be useful over a wide range of streamflow rates but the suitability of dissolved gas methods to determine discharge rates in high gradient mountain streams has not been sufficiently tested, even though headwater streams are critical as ecological habitats and water resources. The aim of this study is to test the suitability of using dissolved gases to determine groundwater discharge rates to high gradient streams by field experiments in a well-characterized, high gradient mountain stream and a literature review. At a reach scale (550 m) we combined stream and groundwater radon activity measurements with an in-stream SF6 tracer test. By means of numerical modeling we determined gas exchange velocities and derived very low groundwater discharge rates (~15% of streamflow). These groundwater discharge rates are below the uncertainty range of physical streamflow measurements and consistent with temperature, specific conductance and streamflow measured at multiple locations along the reach. At a watershed-scale (4 km), we measured CFC-12 and d18O concentrations and determined gas exchange velocities and groundwater discharge rates with the same numerical model. The groundwater discharge rates along the 4 km stream reach were highly variable, but were consistent with the values derived in the detailed study reach. Additionally, we synthesized literature values of gas exchange velocities for different stream gradients which show an empirical relationship that will be valuable in planning future dissolved gas studies on streams with various gradients. In sum, we show that multiple dissolved gas tracers can be used to determine groundwater discharge to high gradient mountain streams from reach to watershed scales.
Weitere Angaben
Publikationsform: | Artikel in einer Zeitschrift |
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Begutachteter Beitrag: | Nein |
Zusätzliche Informationen: | BAYCEER146888 |
Institutionen der Universität: | Forschungseinrichtungen Forschungseinrichtungen > Forschungszentren Forschungseinrichtungen > Forschungszentren > Bayreuther Zentrum für Ökologie und Umweltforschung - BayCEER |
Titel an der UBT entstanden: | Nein |
Themengebiete aus DDC: | 500 Naturwissenschaften und Mathematik |
Eingestellt am: | 02 Mai 2019 11:28 |
Letzte Änderung: | 06 Jul 2022 09:47 |
URI: | https://eref.uni-bayreuth.de/id/eprint/48293 |