Doctoral Dissertation Research: Investigating the Influence of Deforestation on River Incision and Landscape Change

博士论文研究：调查森林砍伐对河流切割和景观变化的影响

• 批准号: 1632977
• 负责人: David Montgomery
• 金额: $ 1.59万
• 依托单位: University of Washington
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-09-01 至 2018-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1632977&HistoricalAwards=false
• 关键词: Doctoral; Dissertation; Research; Investigating; Influence

This doctoral dissertation research project will investigate the impact of deforestation on sediment storage in streams. Deforestation activities reduce the presence of large woody debris in river systems, which results in increased mobility of water and decreased formation of vital biological refuges and floodplains. This project will provide new insights into the process-based understanding of river dynamics and the impacts of human-related geomorphic changes on river erosion rates. By providing a better understanding of the landscape impacts of modified geomorphological patterns, this research has the potential for identifying bedrock (strath) terraces as a physiographic demarcator of the current geologic epoch, which has been called the Anthropocene by many scientists. Project findings will inform water transportation engineers and floodplain restoration agencies seeking to institute better management and restoration strategies for river systems. The doctoral student will work with local schools and student organizations to develop educational materials directed at furthering STEM education programs at those institutions. As a Doctoral Dissertation Research Improvement award, this award will provide support to enable a promising student to establish a strong independent career.Removal of large woody debris from river systems reduces their sediment load and can lead to rapid river incision, thus slowing floodplain formation, changing ecosystem water supply, and affecting flood inundation patterns. This research project will address the spatial and temporal impact of human-related woody debris removal by examining the formation of bedrock terraces in the rivers of the Pacific Northwest. The doctoral student will use radiocarbon dating of charcoal and a novel method of lead-210 dating of floodplain sediment to determine the onset and rate of river incision. A comparative analysis will be performed with long-term incision rates derived during previous studies to assess the current river response to human-related activities. The student will couple archival research with a numerical model in order to assess the long-term topographic impact of deforestation on river valleys. The integration of these methodologies across various spatio-temporal scales will determine if a topographic signature of the Anthropocene is emerging as a result of large-scale forestry practices.

该博士学位论文研究项目将研究森林砍伐对溪流中沉积物存储的影响。 森林砍伐活动减少了河流系统中大型木质碎屑的存在，从而导致水的迁移率增加，并减少了重要的生物避难所和洪泛区的形成。 该项目将为基于过程的河流动力学理解以及与人类相关的地貌变化对河流侵蚀率的影响提供新的见解。 通过更好地了解修改的地貌模式的景观影响，这项研究具有将基岩（Strath）露台鉴定为当前地质时期的生理界限者的潜力，许多科学家被许多科学家称为人类世。 项目调查结果将为供水工程师和洪泛区修复机构提供信息，以寻求制定河流系统的更好的管理和恢复策略。 博士生将与当地学校和学生组织合作，开发针对这些机构进一步发展STEM教育计划的教育材料。 作为博士学位论文研究改进奖，该奖项将提供支持，使有前途的学生能够建立强大的独立职业。从河流系统中销售大型木质碎片可减轻其沉积物负荷，并可以导致快速河流切口，从而减慢洪泛区的形成，改变生态系统的供水，并影响洪水泛滥的模式。 该研究项目将通过检查西北太平洋河流中基岩露台的形成，以解决与人相关的木质碎片清除的空间和时间影响。 博士生将使用木炭的放射性碳年代和一种新颖的铅-210洪泛区沉积物约会方法来确定河流切口的发作和速率。 在先前研究期间得出的长期切口率将进行比较分析，以评估当前河流对与人类相关活动的反应。 该学生将将档案研究与数值模型相结合，以评估森林砍伐对河谷的长期地形影响。 这些方法在各种时空尺度上的整合将决定人类世的地形特征是否由于大规模林业实践而出现。

项目成果

Multiple paths to straths: A review and reassessment of terrace genesis

通往地层的多条路径：梯田起源的回顾和重新评估

• DOI: 10.1016/j.geomorph.2018.03.028
• 发表时间: 2018
• 期刊: Geomorphology
• 影响因子: 3.9
• 作者: Schanz, Sarah A.;Montgomery, David R.;Collins, Brian D.;Duvall, Alison R.
• 通讯作者: Duvall, Alison R.