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Using LIDAR and ArcGIS to describe geomorphometric characteristics of historical hydraulic mining features along the North Yuba River to understand extent of landscape alteration and to inform ranking and prioritization. Brandon Ertis1, Carrie Monohan1,2, Allan James3, David Brown1 1California State University Chico, 2The Sierra Fund, 3University of South Carolina Columbia Overview of Hydraulic Mining Timeline of Hydraulic Mining in California Overview of LIDAR and ArcGIS Creation of hydraulic mining and beginning of Caminetti Act reinstates hydraulic mining, The impacts of hydraulic mining practices to extract gold in the Sierra Nevada mountains LIDAR is a surveying method that measures distance to a target by use in Yuba River watershed to retrieve gold with licensing handled by California Debris that originated over 150 years ago and continued for approximately a century afterwards illuminating that target with a laser light, and it is capable of generating found in alluvial deposits. Commission (CDC). continue to affect water resources in northern California today. Hydraulic mining uses very high resolution landscape maps. The term ‘LIDAR’ originated as a high-pressure jets of water, directed through monitors, to dislodge earthen material and 1853 1893 portmanteau of ‘light’ and ‘radar’ in the 1960’s, although it is also now move sediment. The resulting slurry was directed through wooden sluices, during which Licensed Period of known as an acronym of ‘Light Detection and Ranging.’ The image elemental mercury was incorporated to the slurry to aid in gold extraction. The photo Unlicensed Period of Hydraulic Mining Hydraulic Mining developed by NOAA below shows a LIDAR dataset alongside a photo of below is from Malakoff Diggins, the largest hydraulic mine created in California, and Present Day shows multiple monitors and a wooden sluice. The Yuba River watershed was the most the famous Bixby Bridge along California’s Central Coast. heavily mined; the North Yuba River will be the focus of this research effort. 1848 1884 1950 Discovery of gold in California along South Sawyer Decision ends period of unlicensed Last license is issued by CDC. Fork of the American River. hydraulic mining. Represents the approximate end of hydraulic mining for Negative Impacts of Hydraulic Mining gold in California. • Production and mobilization of massive volumes of sediment. It is estimated that over 1.2 billion cubic meters of sediment and debris was removed from the Sierra Nevada following the discovery of gold during this initial burst of hydraulic mining between the years of 1853 and 1884. Source: National Oceanic and Atmospheric Administration (NOAA) • Introduction of mercury into the environment, where it still persists to this day and has been found in water, sediment, and living organisms from historical mining locations along the Yuba River downstream to the San Francisco Bay where water originating in the Yuba River watershed flows out into the Pacific Ocean. • Under certain conditions, mercury methylation can occur. Methylmercury is a very powerful neurotoxin. It is Source: Source: California Department of Parks and Recreation The LIDAR dataset that will able to bioaccumulate and biomagnify, and it presents a very real danger to people and the environment. www.periodictable.com be used to develop this hydraulic mining feature inventory was developed for the Tahoe National Forest management North Yuba Location Map Research Questions Geomorphometric area using data collected using an Optech Gemini 1. How many hydraulic mining features are present in the study area? Adjective Airborne Laser Terrain Mapper (ALTM) mounted in a 2. What is their geomorphometric characterization and current condition? Describes the science of quantitative twin-engine Piper Navajo PA-31 between 2012 and 2014. 3. What were overall estimated volumes of sediment produced by land surface analysis. The resulting dataset is a Digital Elevation Model (DEM) comprised of a grid of one square meter cells. Source: hydraulic mining sites in the study area? Geomorphometric analysis involves www.aurorasolar.com 4. What are estimated volumes of sediment still remaining within the utilizing various mathematical, watershed? statistical, and image processing ArcGIS is a Geographic 5. Based on results of this study, what is an appropriate methodology for techniques to quantify ecological, Information System (GIS) categorizing and classifying hydraulic mining features in order to hydrological, morphological, or software platform that is prioritize them for further investigation and assessment, with the end topographical characteristics of a widely used for creating goal of environmental remediation? land surface. and using maps, compiling spatial data, analyzing spatial datasets, utilizing The Research Questions will be answered through a two-step process: (1) extensive review and maps and geographic information in a analysis of a LIDAR dataset via the geoprocessing tools available in ArcGIS, and (2) field visits to range of applications, and for Methodology managing geographic and spatial numerous sites to document and characterize hydraulic mining features in person for comparison information in a database. It will be the to LIDAR dataset results. Both LIDAR and ArcGIS are described in further detail to the right. For the primary tool used to analyze the final research question, the results of the inventory and characterization will inform prioritization. available LIDAR dataset. Source: www.arcgis.com Preliminary Results Anticipated Results for the North Yuba Evidence of (for Willow Creek Subwatershed) • A larger number of hydraulic mining features will be identified, mapped, and characterized as part of • Eight major hydraulic mining sites and two debris control dams (DCDs), see Table 1 below for detailed hydraulic results on each individual feature mining in this study than estimates of the number of features from previous studies. • Approximately 10.6 million cubic meters mined* headwaters of • Sediment volumes (1) removed from hydraulic mining sites in the North Yuba River and (2) remaining • Approximately 0.4 million cubic meters entrapped behind DCDs (5% of total mined)* in the watershed will be estimated and used to estimate the proportion of sediment production that • Evidence of hydraulic mining in upper tributaries within subwatershed Williamson Table 1. Willow Creek Subwatershed Hydraulic Mining Feature Inventory Results. Creek moved out of the watershed. Shape Waterway Nearest Waterway Surface Volume Feature Name Classification (Narrow/Open) (Y/N) (Distance in km) Area (m2) (m3) Notes • Using the methodology developed, the hydraulic mining features inventoried will be classified and Feature is also partially prioritized with regard to further investigation and environmental remediation and next steps will be 1 - Joubert Diggins Mining Site Narrow Y Willow Creek 371,078 3,364,441 within Fiddle Creek Ridge subwatershed recommended. 2 Mining Site Open N Willow Creek (0.15) 138,092 220,947 • This study will serve as a pilot study that can then be replicated in other areas affected by hydraulic Willow Creek DCD DCD Sediment Deposit Narrow Y Willow Creek 53,451 309,500 mining, namely the South and Middle Yuba River and the Bear River watersheds. 3 Mining Site Open N Willow Creek (0.16) 102,328 920,952 Horse Valley Creek • The results of this study will be used by USFS to inform their management of the study area. 4 Mining Site Open N 43,918 450,891 (0.34) Evidence of Horse Valley Creek hydraulic 5 Mining Site Open N (0.15) and Brandy 299,354 2,853,841 • References to previous studies or results shown here are cited in Thesis Proposal. Creek (0.19) mining along Horse Valley Notes • The study is currently underway and expected to be complete by May 2018. DCD Sediment Deposit Narrow Y Horse Valley Creek 43,232 75,604 Creek DCD Bridger Creek Willow Creek (0.07), Horse Valley 6 Mining Site Open N 304,953 1,687,407 Creek (0.12), and Brandy Creek (0.21) Project Supporters Feature is also partially Willow Creek (0.26) within the Middle Yuba Willow Creek Subwatershed Hydraulic 7 Mining Site Open N and Oregon Creek 352,024 657,111 watershed and Oregon (0.15) Mining Feature and Location Map Creek subwatershed and Partners: 8 Mining Site Narrow N Willow Creek (0.24) 70,480 455,771 *Volumetric calculations were calculated based on surface area and roughly approximated depth of features. Methods will be refined and improved for actual study. .
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