TY - JOUR
T1 - Factors controlling surface water flow in a low-gradient subtropical wetland
AU - He, Guoqing
AU - Engel, Victor
AU - Leonard, Lynn
AU - Croft, Alex
AU - Childers, Daniel
AU - Laas, Michael
AU - Deng, Yang
AU - Solo-Gabriele, Helena M.
PY - 2010/4
Y1 - 2010/4
N2 - 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 (<3 cm s-1), and exhibited seasonal fluctuations that were correlated withseasonal 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.
AB - 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 (<3 cm s-1), and exhibited seasonal fluctuations that were correlated withseasonal 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.
KW - Florida Everglades
KW - Flow resistance
KW - Restoration
KW - Water speed
KW - Water velocity
UR - http://www.scopus.com/inward/record.url?scp=77956459202&partnerID=8YFLogxK
U2 - 10.1007/s13157-010-0022-1
DO - 10.1007/s13157-010-0022-1
M3 - Article
AN - SCOPUS:77956459202
SN - 0277-5212
VL - 30
SP - 275
EP - 286
JO - Wetlands
JF - Wetlands
IS - 2
ER -