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

SGER：冰后反弹对瑞典河流纵向剖面的影响

• 批准号: 0754135
• 负责人: Ellen Wohl
• 金额: --
• 依托单位: Colorado State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-06-15 至 2009-11-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0754135&HistoricalAwards=false
• 关键词: SGER; Influence; postglacial; rebound; river

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.

该奖项将探索影响河流纵向剖面发展的变量之间的相互作用。主要研究人员将使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将测试一系列的五个假设，重点关注流域面积和流量（H1）、基底性质（H2、H3）和抬升速率（H4）对河流纵剖面和河道几何形状的影响，以及流幂定律描述存在急流（而不是瀑布）形式的缺口的河流切口的充分性（H5）。第二个目标是估计相对侵蚀率在选定的网站沿着每条河流使用阈值碎屑运动和基岩切口结合频率的流量超过这些阈值。本提案中概述的研究将允许PI测试流功率定律沿着河流的适用性，这些河流具有陡峭急流形式的转折点，以及先前调查人员的推断，即对流域面积的隆起尺度的响应。拟议的研究将为研究生和本科生提供实地经验。这项研究还将促进与瑞典河岸生态学家的合作，并增加对冰川消退后河流调整的历史和机制的了解，这是众所周知的影响河岸群落结构和多样性。