Estimating evapotranspiration and groundwater flow from water-table fluctuations for a general wetland scenario
Article first published online: 7 JAN 2013
Published 2013. This article is a U.S. Government work and is in the public domain in the USA.
Volume 7, Issue 2, pages 378–390, April 2014
How to Cite
Carlson Mazur, M. L., Wiley, M. J. and Wilcox, D. A. (2014), Estimating evapotranspiration and groundwater flow from water-table fluctuations for a general wetland scenario. Ecohydrol., 7: 378–390. doi: 10.1002/eco.1356
- Issue published online: 3 APR 2014
- Article first published online: 7 JAN 2013
- Manuscript Accepted: 8 NOV 2012
- Manuscript Revised: 11 JUL 2012
- Manuscript Received: 11 NOV 2011
- USGS Global Change Research Program and the University of Michigan School of Natural Resources and Environment and Rackham Graduate School
- Great Lakes;
- water table;
The use of diurnal water-table fluctuation methods to calculate evapotranspiration (ET) and groundwater flow is of increasing interest in ecohydrological studies. Most studies of this type, however, have been located in riparian wetlands of semi-arid regions where groundwater levels are consistently below topographic surface elevations and precipitation events are infrequent. Current methodologies preclude application to a wider variety of wetland systems. In this study, we extended a method for estimating sub-daily ET and groundwater flow rates from water-level fluctuations to fit highly dynamic, non-riparian wetland scenarios. Modifications included (1) varying the specific yield to account for periodic flooded conditions and (2) relating empirically derived ET to estimated potential ET for days when precipitation events masked the diurnal signal. To demonstrate the utility of this method, we estimated ET and groundwater fluxes over two growing seasons (2006–2007) in 15 wetlands within a ridge-and-swale wetland complex of the Laurentian Great Lakes under flooded and non-flooded conditions. Mean daily ET rates for the sites ranged from 4.0 mm d−1 to 6.6 mm d−1. Shallow groundwater discharge rates resulting from evaporative demand ranged from 2.5 mm d−1 to 4.3 mm d−1. This study helps to expand our understanding of the evapotranspirative demand of plants under various hydrologic and climate conditions. Published 2013. This article is a U.S. Government work and is in the public domain in the USA.