A Hydrologic Landscapes Perspective on Groundwater Connectivity of Depressional Wetlands.
Brian P Neff, Donald O Rosenberry, Scott G Leibowitz, Dave M Mushet, Heather E Golden, Mark C Rains, J Renée Brooks, Charles R Lane
Author Information
Brian P Neff: Former post-doctoral Research Hydrologist, National Research Program, U.S. Geological Survey, Lakewood, CO 80225, USA.
Donald O Rosenberry: Earth System Processes Division, Water Mission Area, U.S. Geological Survey, Lakewood, CO 80225, USA.
Scott G Leibowitz: Pacific Ecological Systems Division, Center for Public Health and Environmental Assessment, U.S. Environmental Protection Agency, Corvallis, OR 97333, USA.
Dave M Mushet: Northern Prairie Wildlife Research Center, U.S. Geological Survey, Jamestown, ND 58401-7317, USA.
Heather E Golden: Center for Environmental Measurement and Modeling, Office of Research and Development, U.S. Environmental Protection Agency, Cincinnati, OH 45268, USA.
Mark C Rains: School of Geosciences, University of South Florida, Tampa, FL 33620, USA.
J Renée Brooks: Pacific Ecological Systems Division, Center for Public Health and Environmental Assessment, U.S. Environmental Protection Agency, Corvallis, OR 97333, USA.
Charles R Lane: Center for Environmental Measurement and Modeling, Office of Research and Development, U.S. Environmental Protection Agency, Cincinnati, OH 45268, USA.
Research into processes governing the hydrologic connectivity of depressional wetlands has advanced rapidly in recent years. Nevertheless, a need persists for broadly applicable, non-site-specific guidance to facilitate further research. Here, we explicitly use the hydrologic landscapes theoretical framework to develop broadly applicable conceptual knowledge of depressional-wetland hydrologic connectivity. We used a numerical model to simulate the groundwater flow through five generic hydrologic landscapes. Next, we inserted depressional wetlands into the generic landscapes and repeated the modeling exercise. The results strongly characterize groundwater connectivity from uplands to lowlands as being predominantly indirect. Groundwater flowed from uplands and most of it was discharged to the surface at a concave-upward break in slope, possibly continuing as surface water to lowlands. Additionally, we found that groundwater connectivity of the depressional wetlands was primarily determined by the slope of the adjacent water table. However, we identified certain arrangements of landforms that caused the water table to fall sharply and not follow the surface contour. Finally, we synthesize our findings and provide guidance to practitioners and resource managers regarding the management significance of indirect groundwater discharge and the effect of depressional wetland groundwater connectivity on pond permanence and connectivity.
