Quantifying and Predicting the Attenuation of Downstream Fluxes Associated with Beaver Meadows

Colorado State University, Fort Collins CO

Investigators

Abstract

Predicted warming and drying across much of the U.S. will stress existing water supplies for consumptive activities, as well as ecosystem health and resilience. This is particularly true for the arid and semi-arid regions of the western U.S., including headwater states such as Colorado. Given the predicted increased potential for droughts and floods in the region, the ability to retain and gradually release water from surface and subsurface retention zones within river basins is important. This study will evaluate the potential for beaver meadows which contain numerous dams, ponds, and multi-thread channels, to substantially attenuate downstream fluxes of water, sediment, organic matter, and nitrate relative to river segments without beaver activity. Results of this work will be important for restoring river function, attenuating flood pulses and augmenting low flow periods, as well as for mitigating potential effects of climate change. In this study investigators will (1) quantify the magnitude of downstream-flux attenuation as a function of size of the beaver meadow relative to the contributing drainage area and activity/spatial heterogeneity of the meadow, (2) evaluate how meadow position within a catchment affects downstream attenuation, (3) assess the extent and magnitude of landscape alteration in the region, and (4) estimate the potential influence of landscape alteration on hydrologic dynamics across larger spatial extents. Quantitative interdisciplinary methods from both hydrology and geomorphology will be leveraged to quantify relationships between catchment morphology, storage, and flux and to scale these dynamics to larger spatial extents. The research will develop new insights into the buffering capacities offered by retention zones in the form of beaver meadows and develop new conceptualizations and numerical models on the manner in which reach-scale behavior influences catchment-scale process.