Quantifying hydrologic connectivity of wetlands to surface water
Ali A. Ameli and Irena F. Creed
Department of Biology, Western University, London, Ontario, Canada
Received: 10 Aug 2016 – Accepted for review: 11 Aug 2016 – Discussion started: 15 Aug 2016
Abstract. Hydrologic connectivity of wetlands is poorly characterized and understood. Our inability to quantify this connectivity compromises our understanding of the potential impacts of wetland loss on watershed structure, function and water supplies. We develop a computationally efficient physically-based subsurface-surface hydrological model to characterize both the subsurface and surface hydrologic connectivity of "geographically isolated" wetlands and explore the time and length variations in these connections to a river within the Prairie Pothole Region of North America. Despite a high density of geographically isolated wetlands (i.e., wetlands without surface outlets), modeled connections show that these wetlands are not hydrologically isolated. Hydrologic subsurface connectivity differs significantly from surface connectivity in terms of timing and length of connections. Slow subsurface connections between wetlands and the downstream river originate from wetlands throughout the watershed, whereas fast surface connections were limited to large events and originate from wetlands located near the river. This modeling approach provides first ever insight on the nature of geographically isolated wetland subsurface and surface hydrological connections to rivers, and provides valuable information to support watershed-scale decision making for water resource management.
Ameli, A. A. and Creed, I. F.: Quantifying hydrologic connectivity of wetlands to surface water
systems, Hydrol. Earth Syst. Sci. Discuss., doi:10.5194/hess-2016-404, in review, 2016.