Factors Controlling Surface Water Flow in a Low-gradient Subtropical Wetland

Authors

Guoqing He, College of Civil Engineering and Architecture, Zhejiang UniversityFollow
Victor Engel, South Florida Natural Resources Center, Everglades National Park,Follow
Lynn Leonard, Department of Geography and Geology, University of North Carolina WilmingtonFollow
Alex Croft, Department of Geography and Geology, University of North Carolina WilmingtonFollow
Dan Childers, Department of Biological Sciences and Southeast Environmental Research Center, Florida International University and School of Sustainability, Arizona State UniversityFollow
Michael Laas, Department of Civil, Architectural and Environmental Engineering, University of MiamiFollow
Yang Deng, Department of Civil, Architectural and Environmental Engineering, University of MiamiFollow
Helena M. Solo-Gabriele, Department of Civil, Architectural and Environmental Engineering, University of MiamiFollow

Abstract

Surface water flow patterns in wetlands play a role in shaping substrates, biogeochemical cycling, and ecosystem characteristics. This paper focuses on the factors controlling flow across a large, shallow gradient subtropical wetland (Shark River Slough in Everglades National Park, USA), which displays vegetative patterning indicative of overland flow. Between July 2003 and December 2007, flow speeds at five sites were very low (s−1), and exhibited seasonal fluctuations that were correlated with seasonal changes in water depth but also showed distinctive deviations. Stepwise linear regression showed that upstream gate discharges, local stage gradients, and stage together explained 50 to 90% of the variance in flow speed at four of the five sites and only 10% at one site located close to a levee-canal combination. Two non-linear, semi-empirical expressions relating flow speeds to the local hydraulic gradient, water depths, and vegetative resistance accounted for 70% of the variance in our measured speed. The data suggest local-scale factors such as channel morphology, vegetation density, and groundwater exchanges must be considered along with landscape position and basin-scale geomorphology when examining the interactions between flow and community characteristics in low-gradient wetlands such as the Everglades.

Comments

Copyright © 2010 Springer.

The definitive publisher-authenticated version is available online at http://dx.doi.org/10.1007/s13157-010-0022-1

This material is based upon work supported by the National Science Foundation through the Florida Coastal Everglades Long-Term Ecological Research program under Cooperative Agreements #DBI-0620409 and #DEB-9910514. Any opinions, findings, conclusions, or recommendations expressed in the material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation.

Recommended Citation

He, G., V. Engel, L. Leonard, A.L. Croft, D.L. Childers, M. Laas, Y. Deng, H. Solo-Gabriele. 2010. Factors Controlling Surface Water Flow in a Low-gradient Subtropical Wetland. Wetlands 30: 275-286.