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.

Amanda Schmidt，Paul Bierman，Dylan Roodoberlin学院，佛蒙特大学，加利福尼亚大学？圣巴巴拉蒂（Santa Barbarathis）项目将将每日沉积物产量的记录与同位素库存结合在一起，以破译土地利用，土壤侵蚀和沉积物产量之间的连接，这些河流排干藏族高原。沉积物产量数据，每天针对44个站进行测量，每个站点都有27年的每日沉积物浓度和排放记录，这表明在这些盆地中，尽管有明显且有据可查的土地清除，但在这些盆地中，沉积物产量随着时间的推移没有系统的增加。研究人员将将沉积物产量数据与对3个同位素系统的分析相结合，以了解为什么30年的广泛森林砍伐不会改变沉积物的产量。他们的同位素分析将记录沉积物来源，下沉和运动速率。他们将使用一个原位10BE的同位素系统来计算在千禧一代时间表上集成的背景侵蚀率；可以将现代沉积物产量数据进行比较的速率。第二个同位素系统，即恒星10BE，将是沉积物混合而受到严重干扰和受扰动区域的混合的示踪剂，并且可以与沉积物产量相结合以估计土壤损失。第三个同位素系统，137CS和210pb，将使研究人员能够确定运输中的沉积物来自深沟/滑坡侵蚀，以及来自近地面沉积物来源的多少。该项目将提供背景侵蚀率，可以将其与现代沉积物产量数据进行比较。此外，这项工作将提供一种强大的方法来识别受到严重干扰并正在失去土壤的子碱，即使大部分土壤没有进入河流网络。在现场和遥感中，地貌映射都将决定在景观上以甲壳和梯田和梯田的范围内储存多少侵蚀的沉积物。该项目将提供有关土地利用如何在不同的空间和时间尺度上影响土壤侵蚀和沉积物产量的信息，这是在世界各地山区实施有意义的土地利用政策的关键数据。中国政府正在研究区建造一系列水坝，这是近20亿人的淡水来源。了解沉积物从斜坡上移动到频道和下游的时间尺度对于确定全球山区山区和其他大坝的寿命至关重要。该项目将在一个杰出的本科机构，指导最先进的研究机构的高级研究员以及研究机构的早期职业科学家中，将早期的职业教师汇集在一起博士生的科学教育和教学培训。