SGER: Influence of postglacial rebound on river longitudinal profiles in Sweden

该奖项将探索影响河流纵剖面发展的变量之间的相互作用。首席研究员将利用瑞典广泛的冰川引起的隆起提供的自然实验，其中包含一系列具有相似特征但基准面历史略有不同的河流。PI将测试一系列五个假设，重点关注流域面积和流量（H1）、基岩特性（H2, H3）和抬升速率（H4）对河流纵剖面和河道几何形状的影响，以及河流幂律在描述以急流（而不是瀑布）形式存在的河流切口时的充分性（H5）。第二个目标是利用碎屑运动和基岩切割的阈值，结合超过这些阈值的流量频率，估计每条河流选定地点的相对侵蚀率。本提案中概述的研究将允许PI测试沿具有陡峭激流形式的裂缝的河流的流功率定律的适用性，以及先前研究人员对排水面积的隆起尺度的响应的推断。更广泛的影响。建议的研究将为研究生和本科生提供实地经验。该研究还将促进与瑞典河岸生态学家的合作，并增加对冰川消融后河流调整的历史和机制的理解，这一过程已知会影响河岸群落结构和多样性。

This award will explore interactions among variables that influence the development of a river's longitudinal profile. The Principal Investigator will use the natural experiment provided by the widespread glacially induced uplift in Sweden, which contains a series of rivers with similar characteristics but slightly different base level histories. The PI will test a series of five hypotheses that focus on the influence of drainage area and discharge (H1), substrate properties (H2, H3), and uplift rate (H4) on river longitudinal profile and channel geometry, and on the adequacy of a stream power law to describe river incision where knickpoints in the form of rapids (rather than waterfalls) are present (H5). A second objective is to estimate relative erosion rates at selected sites along each river using thresholds for clast motion and bedrock incision combined with the frequency of flows exceeding these thresholds. The research outlined in this proposal will allow the PI to test the applicability of the stream power law along rivers with knickpoints in the form of steep rapids, and the inference of previous investigators that response to uplift scales with drainage area.Broader Impacts. The proposed research will provide field experience for graduate and undergraduate students. The research will also foster collaboration with Swedish riparian ecologists, and increase understanding of the history and mechanics of river adjustment following deglaciation, which are known to influence riparian community structure and diversity.