Fluvial geomorphology and the winter habitat of stream salmonids

该研究计划的长期目标是提高我们对河流形式和控制河流鲑鱼冬季栖息地的过程的理解。砾石河床河流通常可分为若干离散的沉积环节，每个环节的特点是粗泥沙补充的节点，随后是下游基质逐渐变细和相关的河道坡度减小。由于下游变化的衬底和坡度沿着沉积环节与通道形态和水力学的变化，他们创建一个纵向序列的水生栖息地类型移动从陡峭，快速流动和湍流卵石床通道的头部链接到蜿蜒，缓慢流动，低梯度砂渠道的下游端。在接下来的五年里，我将更密切地调查的重要作用，沉积环节控制的空间和时间分布的青少年大西洋鲑鱼冬季栖息地在砾石床河流。拟议研究的具体目标是：（1）为了检验沉积联系对幼大西洋鲑鱼冬季栖息地的空间和时间模式施加强有力控制的假设，（2）为了检验沉积联系对河流冰类型的大规模分布施加强有力控制的假设，（3）研究幼鲑对河冰形成所造成的生境条件变化的反应;（4）评估锚冰对幼鲑产卵基质间隙流速度的影响。

The long-term objective of the research program is to improve our understanding of the fluvial forms and processes controlling the winter habitat of stream salmonid. Gravel-bed rivers can often be segmented into a number of discrete sedimentary links, each characterized by a node of coarse sediment recruitment followed by a gradual downstream fining of substrate and an associated reduction of channel slope. Because the downstream changes in substrate and slope along sedimentary links are associated with changes in channel morphology and hydraulics, they create a longitudinal sequence of aquatic habitat types moving from steep, fast flowing and turbulent boulder bed channels at the head of links to meandering, slow-flowing, low-gradient sand channels at the downstream end. Over the next five years, I will investigate more closely the important role of sedimentary links in controlling the spatial and temporal distribution of juvenile Atlantic salmon winter habitat in gravel-bed rivers. The specific objectives of the proposed research are: (1) To test the hypothesis that sedimentary links exerts a strong control on the spatial and temporal pattern of juvenile Atlantic salmon winter habitat, (2) To test the hypothesis that sedimentary links exerts a strong control on the large-scale distribution of river ice types, (3) To investigate the response of salmon parr to the changing habitat conditions created by the formation of river ice, and (4) To asses the effect of anchor ice on the interstitial flow velocities of salmonid spawning substrates.