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Quantification of surface water and groundwater flows to open - and closed-basin lakes in a headwaters watershed using a descriptive oxygen stable isotope model

Water Resources Research

By:
, , , and
DOI: 10.1029/2009WR007793

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Abstract

Accurate quantification of hydrologic fluxes in lakes is important to resource management and for placing hydrologic solute flux in an appropriate biogeochemical context. Water stable isotopes can be used to describe water movements, but they are typically only effective in lakes with long water residence times. We developed a descriptive time series model of lake surface water oxygen-18 stable isotope signature (??L) that was equally useful in open- and closed-basin lakes with very different hydrologic residence times. The model was applied to six lakes, including two closed-basin lakes and four lakes arranged in a chain connected by a river, located in a headwaters watershed. Groundwater discharge was calculated by manual optimization, and other hydrologic flows were constrained by measured values including precipitation, evaporation, and streamflow at several stream gages. Modeled and observed ??L were highly correlated in all lakes (r = 0.84-0.98), suggesting that the model adequately described ??L in these lakes. Average modeled stream discharge at two points along the river, 16,000 and 11,800 m3 d -1, compares favorably with synoptic measurement of stream discharge at these sites, 17,600 and 13,700 m3 d-1, respectively. Water yields in this watershed were much higher, 0.23-0.45 m, than water yields calculated from gaged streamflow in regional rivers, approximately 0.10 m, suggesting that regional groundwater discharge supports water flux through these headwaters lakes. Sensitivity and robustness analyses also emphasized the importance of considering hydrologic residence time when designing a sampling protocol for stable isotope use in lake hydrology studies. Copyright 2010 by the American Geophysical Union.

Additional Publication Details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
Quantification of surface water and groundwater flows to open - and closed-basin lakes in a headwaters watershed using a descriptive oxygen stable isotope model
Series title:
Water Resources Research
DOI:
10.1029/2009WR007793
Volume
46
Issue:
3
Year Published:
2010
Language:
English
Larger Work Type:
Article
Larger Work Subtype:
Journal Article
Larger Work Title:
Water Resources Research