Published on January 3, 2008
QUANTIFYING WETLANDS FUNCTIONS:A CASE STUDY: QUANTIFYING WETLANDS FUNCTIONS: A CASE STUDY Ken Potter, Justin Rogers, Adam Hoffman, Chin Wu, John A. Hoopes, and David E. Armstrong University of Wisconsin-Madison ACKNOWLEDGEMENTS: ACKNOWLEDGEMENTS This research was supported by a grant from the U.S. Department of Agriculture and the Environmental Protection Agency. WETLAND SERVICES: WETLAND SERVICES Flood abatement Water quality improvement Sediment Phosphorus Nitrogen Habitat The first two services have rarely been rigorously quantified. Depend on connectivity of system. Slide4: UPPER DORN CREEK WETLAND UPPER DORN CREEK WETLAND: UPPER DORN CREEK WETLAND MEASUREMENT LOCATIONS: MEASUREMENT LOCATIONS Dorn Gage Ripp Gage HYDRAULIC MODELING RESULTS: HYDRAULIC MODELING RESULTS CONCLUSIONS - PEAKS: CONCLUSIONS - PEAKS The wetland attenuated all peaks, with maximum attenuation for intermediate peaks. Small events did not reach wetland. Large events filled storage. CONCLUSIONS - SEDIMENT: CONCLUSIONS - SEDIMENT For the two largest events, which accounted for 96% of the sediment exported, the sediment outflow was about 100% greater than the inflow. Erosion of sediment in the main channel Erosion of sediment in the two primary ditches CONCLUSIONS - PHOSPHORUS: CONCLUSIONS - PHOSPHORUS The wetland sequestered 40% of the dissolved reactive phosphorus. The wetland released 34% more particulate-bound phosphorus than it received. Overall, the wetland had no impact on the transport of total phosphorus. CONCLUSIONS: CONCLUSIONS The hydrologic functions of wetlands depend on the connectivity of the wetland and major flows of water, which are controlled by Topography Hydrology Hydrodynamics RECOMMENDATIONS: RECOMMENDATIONS Sediment and phosphorus trapping by the Dorn Creek wetland could be significantly enhanced by increasing connectivity: Eliminating the drainage ditches; Installing a control structure on the main channel at the head of the wetland.