Table of Contents
ISRN Soil Science
Volume 2012, Article ID 726806, 15 pages
http://dx.doi.org/10.5402/2012/726806
Research Article

Estimation of Evapotranspiration and Water Budget Components Using Concurrent Soil Moisture and Water Table Monitoring

1Division of Facilities Planning, Design, and Construction, Pinellas County Schools, 11111 Belcher Road, Largo, FL 33773, USA
2Environment and Infrastructure Division, Department of Civil and Water Resources, AMEC Inc., 2000 E. Edgewood Drive, Lakeland, FL 33803, USA
3Center for Modeling Hydrologic and Aquatic Systems and Department of Civil and Environmental Engineering, University of South Florida, 4202 E. Fowler Avenue, Tampa, FL 33620, USA

Received 6 December 2011; Accepted 29 January 2012

Academic Editor: L. D. Chen

Copyright © 2012 Mandana Rahgozar et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Simultaneous measurements of soil moisture profiles and water table heads, along a flow path, were used to determine evapotranspiration (ET) along with other components of the water budget. The study was conducted at a small-scale (~0.8 Km2) hydrologic monitoring field site in Hillsborough County, Florida, from January 2002 to June 2004. Frequency Domain Reflectometry soil moisture probes, installed in close proximity to water table monitoring wells were used to derive changes in the soil water storage. A one-dimensional transect model was developed; changes in the soil water storage and water table observations served as input to determine all vertical and lateral boundary fluxes along the shallow water table flow plane. Two distinct land cover environments, grassland and an alluvial wetland forest, were investigated in this particular study. The analysis provided temporally variable ET estimates for the two land covers with annual totals averaging 850 mm for grassland, to 1100 mm for the alluvial wetland forest. Quantitative estimates of other components of a water budget, for example, infiltration, interception capture, total rainfall excess, and runoff were also made on a quarterly and annual basis. Novelty of this approach includes ability to resolve ET components and other water budget fluxes that provide useful parameterization and calibration potential for predictive simulation models.