Quantifying Climatic Controls on Sediment Production and Hillslope Evolution

量化沉积物产生和山坡演化的气候控制

• 批准号: 0309975
• 负责人: Joshua Roering
• 金额: $ 24万
• 依托单位: University of Oregon Eugene
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-09-15 至 2007-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0309975&HistoricalAwards=false
• 关键词: Quantifying; Climatic; Controls; Sediment; Production

Joshua J. Roering (EAR-0309975)University of OregonSedimentary deposits proximal to hilly and mountainous terrain record significant variations in sediment delivery over the last 2-3 million years. These fluctuations have been associated with climate change although the responsible mechanisms are poorly known. In such landscapes, analyses of lake-sediment cores often reveal a complex temperature and moisture history as manifested by the temporal pattern of vegetation regimes. While the influence of vegetation on hydrological processes has been well studied, the role of vegetation in the mobilization and transport of soil into channels is not well understood. Because recent evidence suggests that the mixing and disruption of soils by the activity of biological organisms may play a dominant role in the downslope movement of soil, hillslope evolution may be closely tied to temporal changes in ecosystem properties. As a result, current hillslope characteristics reflect a complex history modulated by climate-related changes in vegetation.PI will quantify the influence of climate-related vegetation changes on sediment production and hillslope evolution by documenting and modeling the transport of soil and naturally-occurring tracers in field sites with variable paleo-environmental records. At our loess-mantled study sites in New Zealand and the Columbia Plateau, USA, we will use soil stratigraphy, high-resolution topographic data, and detailed characterizations of tephra deposits to quantify paleo-hillslope geometry and characterize soil transport processes. Along hillslope transects, he will use buried tephra deposits as both a marker bed for recording exhumation and a tracer for documenting how hillslope processes mix and displace soil. When combined, soil, paleo-environmental, topographic, and tephra datasets will enable him to test soil transport models and reconstruct how climate change regulated transport rates and hillslope dynamics in the late Quaternary. PI's results will be useful for newly emerging carbon sequestration and transport calculations as well as land management strategies.

约书亚J.罗林（乔-0309975）俄勒冈大学丘陵和山区地形附近的沉积物记录了过去200 - 300万年来沉积物输送的显著变化。 这些波动与气候变化有关，尽管人们对负责的机制知之甚少。 在这样的景观，湖泊沉积物芯的分析往往揭示了一个复杂的温度和湿度的历史表现为植被制度的时间模式。 虽然植被对水文过程的影响已经得到了很好的研究，但植被在土壤动员和运输到渠道中的作用还没有得到很好的理解。 由于最近的证据表明，混合和破坏土壤的生物有机体的活动可能发挥主导作用，在下坡运动的土壤，山坡演变可能是密切相关的时间变化的生态系统的属性。 因此，目前的山坡特征反映了一个复杂的历史调制的气候相关的植被变化。PI将量化的影响，气候相关的植被变化对沉积物的生产和山坡演变的记录和模拟的土壤和自然发生的示踪剂在现场的传输与变量古环境记录。在新西兰和美国哥伦比亚高原的黄土覆盖的研究地点，我们将使用土壤地层学、高分辨率地形数据和火山灰沉积物的详细特征来量化古山坡几何形状和表征土壤运输过程。 沿着沿着山坡样带，他将使用埋藏的火山灰沉积物作为记录挖掘的标记床和记录山坡过程如何混合和置换土壤的示踪剂。 当结合起来时，土壤、古环境、地形和火山灰数据集将使他能够测试土壤迁移模型并重建气候变化如何调节第四纪晚期的迁移率和山坡动态。 PI的结果将是有用的新出现的碳固存和运输计算以及土地管理战略。