Collaborative Research: Deciphering connections among land management, soil erosion, and sediment yield in large river basins

合作研究：破译大河流域土地管理、土壤侵蚀和产沙量之间的联系

• 批准号: 1114436
• 负责人: Dylan Rood
• 金额: $ 15万
• 依托单位: University of California-Santa Barbara
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-09-15 至 2016-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1114436&HistoricalAwards=false
• 关键词: Collaborative; Research; Deciphering; connections; among

Amanda Schmidt, Paul Bierman, Dylan RoodOberlin College, University of Vermont, University of California ? Santa BarbaraThis project will combine a daily record of sediment yield with isotopic inventories to decipher the connections among land use, soil erosion, and sediment yield in 4 large rivers draining the Tibetan Plateau. Sediment yield data, measured daily for 44 stations, each with up to 27 years of daily sediment concentration and discharge records, suggest that in these basins there is no systematic increase in sediment yield over time despite significant, and well-documented, land clearance. The investigators will combine the sediment yield data with analysis of 3 isotopic systems to understand why 30 years of extensive deforestation did not change sediment yield. Their isotopic analyses will document sediment sources, sinks, and rates of movement. They will use one isotopic system, in situ 10Be, to calculate background erosion rates integrated over millennial timescales; rates that can be compared to modern sediment yield data. A second isotopic system, meteoric 10Be, will be a tracer for sediment mixing from heavily disturbed and less-disturbed regions, and can additionally be combined with sediment yields to estimate soil loss. The third isotopic system, 137Cs and 210Pb, will allow investigators to determine how much sediment in transport comes from deep gully/landslide erosion and how much comes from near surface sediment sources. This project will provide background erosion rates that can be compared to modern sediment yield data. Furthermore, the work will provide a robust means of identifying sub-basins that are heavily disturbed and are losing soil, even if much of that soil is not making it into the river network. Geomorphic mapping, both in the field and through remote sensing, will determine where and how much eroded sediment is stored on the landscape as colluvium and in terraces. This project will provide information about how land-use affects soil erosion and sediment yield at different spatial and temporal scales, critical data for implementing meaningful land-use policies in mountainous regions around the world. The Chinese government is building a series of dams in the study area, the source of fresh water for nearly 2 billion people. Understanding the time scales over which sediment moves off slopes, into channels, and downstream is critical for determining the life span of these and other dams in mountainous areas worldwide. This project will bring together an early career faculty member at an exceptional undergraduate institution, a senior researcher who directs a state-of-the-art research facility, and an early career scientist at a research facility in order to achieve maximum enrichment of both undergraduate science education and pedagogical training for the doctoral students.

阿曼达施密特，保罗比尔曼，迪伦鲁德奥伯林学院，佛蒙特大学，加州大学？圣巴巴拉这个项目将联合收割机结合每天的泥沙产量记录和同位素库存，以破译土地利用、土壤侵蚀和青藏高原4条大河的泥沙产量之间的联系。每天测量44个站点的产沙量数据，每个站点都有长达27年的日沉积物浓度和流量记录，这些数据表明，在这些流域，尽管进行了大量有据可查的土地清理，但产沙量并没有随着时间的推移而系统地增加。研究人员将联合收割机的泥沙产量数据与3同位素系统的分析相结合，以了解为什么30年的大规模森林砍伐没有改变泥沙产量。它们的同位素分析将记录沉积物的源、汇和移动速率。他们将使用一个同位素系统，原位10 Be，计算千年时间尺度上的背景侵蚀速率;可以与现代沉积物产量数据进行比较的速率。第二个同位素系统，流星体10 Be，将是一个示踪剂的沉积物混合从严重干扰和较少干扰的地区，并可以另外结合沉积物产量估计土壤流失。第三个同位素系统，137 Cs和210 Pb，将使研究人员能够确定有多少沉积物来自深沟/滑坡侵蚀，有多少来自近地表沉积物来源。该项目将提供可与现代沉积量数据相比较的背景侵蚀率。此外，这项工作将提供一种强有力的手段，以确定受到严重干扰和正在失去土壤的子流域，即使大部分土壤没有进入河流网络。在实地和通过遥感进行的地貌测绘将确定侵蚀沉积物作为崩积层和梯田储存在地貌上的位置和数量。该项目将提供关于土地使用如何在不同的空间和时间尺度上影响土壤侵蚀和沉积量的信息，这是在世界各地山区执行有意义的土地使用政策的关键数据。中国政府正在研究区域建造一系列大坝，这是近20亿人的淡水来源。了解沉积物从斜坡上移动到河道和下游的时间尺度对于确定这些和世界各地山区其他水坝的寿命至关重要。该项目将汇集一个特殊的本科院校的早期职业教师，一个高级研究员，他指导一个最先进的研究设施，以及一个研究设施的早期职业科学家，以实现最大限度地丰富本科科学教育和博士生的教学培训。