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

预计美国大部分地区将出现变暖和干旱，这将给消费活动以及生态系统的健康和弹性带来现有的供水压力。这在美国西部的干旱和半干旱地区尤其如此，包括科罗拉多州等源头州。鉴于预计该区域旱灾和洪涝灾害的可能性将增加，从河流流域的地表和地下保留区保留和逐步释放水的能力很重要。这项研究将评估包含大量水坝、池塘和多线程渠道的海狸草甸相对于没有海狸活动的河段而言，显著减弱下游水、泥沙、有机物和硝酸盐通量的潜力。在这项研究中，研究人员将(1)量化下游通量衰减的大小，作为相对于贡献的流域面积和草甸的活动/空间异质性的函数；(2)评估集水区内草甸的位置如何影响下游衰减；(3)评估区域内景观变化的程度和幅度；(4)估计景观变化对更大范围内水文动力学的潜在影响。将利用水文学和地貌学的定量跨学科方法来量化集水区形态、蓄水和通量之间的关系，并将这些动态扩展到更大的空间范围。这项研究将对海狸草甸形式的保留区提供的缓冲能力产生新的见解，并就到达尺度行为影响流域尺度过程的方式开发新的概念化和数值模型。

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.