Hydraulic Mining Sediments in the Bear and South Yuba Rivers of California

加利福尼亚州熊河和南尤巴河的水力采矿沉积物

• 批准号: 8822436
• 负责人: Allan James
• 金额: $ 4.76万
• 依托单位: University of South Carolina at Columbia
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1989
• 资助国家: 美国
• 起止时间: 1989-05-15 至 1990-10-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=8822436&HistoricalAwards=false
• 关键词: Hydraulic; Mining; Sediments; Bear; South

In many parts of the world, a significant form of human impact on the natural environment has been the disruption caused by using hydraulic mining techniques. These techniques, which use pressurized water to loosen and transport enormous amounts of overburden and ore, introduced enormous quantities of sediment and waste water into natural watersheds. The earliest large-scale use of hydraulic mining in the United States took place in the gold fields of northern California between the 1850s and the 1880s. Considerable attention was focused on the processes of human-induced geomorphic change by scientists including G.K. Gilbert in the early decades of this century, but physical geographers, geologists, hydrologists, and other scholars have turned their attention toward other facets of sedimentary processes in more recent decades. This project will build upon earlier studies of the impacts of hydraulic mining in northern California and more recent work on human-related sedimentary activity to examine the ongoing redistribution of sediment in the upper stretches of the Bear and South Yuba rivers. The project will consist of four interrelated parts: (1) past and present locations and volumes of mining sediments will be mapped using aerial photographs, satellite images, and samples taken during field surveys, (2) measurements of sustained sediment mobility will be made, (3) the changes in stream channels and sediment distributions resulting from a record flood in 1986 will be determined, and (4) the extent of mixing between mining and non-mining sediments will be measured. This research will have a number of theoretical and practical benefits. It will provide the first long-term reassessment of a model of sediment transport first developed by Gilbert in the 1910s, using measurement and analytic techniques that can be used by scholars elsewhere. Although focusing on sediments resulting from mining activities, the project will provide more accurate estimates of the rate and volume of movement for all types of sediments within streams. This improved understanding will provide a basis for more effective decision making regarding the cessation and clean-up of accelerated sedimentation in the nation's streams.

在世界许多地区，人类对自然环境影响的一种重要形式是使用水力采矿技术造成的破坏。这些技术使用加压水来疏松和运输大量的覆盖层和矿石，将大量的泥沙和废水引入天然流域。美国最早的大规模水力采矿发生在19世纪50年代至80年代之间的加利福尼亚州北部的金矿。本世纪头几十年，包括吉尔伯特在内的科学家对人类引起的地貌变化过程给予了相当大的关注，但近几十年来，物理地理学家、地质学家、水文学家和其他学者将注意力转向了沉积过程的其他方面。该项目将建立在对加利福尼亚州北部水力采矿影响的早期研究和最近对与人类有关的沉积活动的研究的基础上，以检查贝尔河和南尤巴河上游正在进行的沉积物重新分配。该项目将由四个相互关联的部分组成：(1)利用航空摄影、卫星图像和实地调查期间采集的样本绘制采矿沉积物的过去和现在的位置和体积；(2)测量持续的泥沙流动；(3)确定1986年创纪录的洪水造成的河道和泥沙分布的变化；(4)测量采矿和非采矿沉积物的混合程度。这一研究将具有一定的理论和实践意义。它将首次对吉尔伯特在1910年代首次开发的泥沙运移模型进行长期重新评估，使用可供其他学者使用的测量和分析技术。虽然该项目侧重于采矿活动产生的沉积物，但将更准确地估计河流中所有类型沉积物的移动速度和数量。这一更好的认识将为更有效地制定停止和清理国家河流加速淤积的决策提供基础。