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

预计美国大部分地区的变暖和干燥将对现有的消费活动供水以及生态系统的健康和恢复力造成压力。这对于美国西部的干旱和半干旱地区尤其如此，包括像科罗拉多这样的源头州。鉴于预计该区域发生干旱和洪水的可能性增加，保持和逐步释放河流流域内地表和地下蓄水区的水的能力十分重要。这项研究将评估海狸草甸，其中包含众多的水坝，池塘，和多线程的渠道，大大削弱下游通量的水，沉积物，有机物和硝酸盐相对于没有海狸活动的河段的潜力。 这项工作的结果将是重要的恢复河流功能，衰减洪水脉冲和增加低流量时期，以及减轻气候变化的潜在影响。在这项研究中，调查人员将（1）量化下游通量衰减的大小作为海狸草甸的大小相对于贡献流域面积和草甸的活动/空间异质性的函数，（2）评估流域内草甸位置如何影响下游衰减，（3）评估该地区景观变化的范围和幅度，（4）估计景观变化对更大空间范围内水文动力学的潜在影响。水文学和地貌学的定量跨学科方法将被用来量化流域形态，存储和通量之间的关系，并将这些动态扩展到更大的空间范围。这项研究将开发新的见解保留区提供的缓冲能力，海狸草甸的形式，并开发新的概念和数值模型的方式，达到规模的行为影响集水规模的过程。

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.