Coastal Ecosystem Investigations with LiDAR (Light Detection and Ranging) and Bottom Reflectance: Lake Superior Reef Threatened by Migrating Tailings

Remote Sensing

ColinN. Brooks¹  SarahA. Green²  MartinM. Hobmeier²  Foad Yousef²  W.Charles Kerfoot²  Robert Shuchman³  Mike Sayers³  Phu Luong⁴  Lihwa Lin⁴  Earl Hayter⁵  Molly Reif⁵ 

[1]Department of Biological Sciences, Michigan Technological University, Houghton, MI 49931, USA

[2]Great Lakes Research Center, Michigan Technological University, Houghton, MI 49931, USA

[3]Michigan Tech Research Institute, Ann Arbor, MI 48105, USA

[4]U.S. Army Engineer Research and Development Center (ERDC-Coastal and Hydraulics Laboratory), Vicksburg, MS 39180, USA

[5]U.S. Army Engineer Research and Development Center (ERDC-Environmental Laboratory), Vicksburg, MS 39180, USA

关键词: remote sensing;    LiDAR;    bottom reflectance;    Lake Superior;    mine tailings;    hydrodynamic modeling;    coastal environment;    Buffalo Reef;    lake trout and whitefish;    sand mixtures;   

DOI  :  10.3390/rs11091076

来源: DOAJ

【 摘 要 】

Where light penetration is excellent, the combination of LiDAR (Light Detection And Ranging) and passive bottom reflectance (multispectral, hyperspectral) greatly aids environmental studies. Over a century ago, two stamp mills (Mohawk and Wolverine) released 22.7 million metric tons of copper-rich tailings into Grand Traverse Bay (Lake Superior). The tailings are crushed basalt, with low albedo and spectral signatures different from natural bedrock (Jacobsville Sandstone) and bedrock-derived quartz sands. Multiple Lidar (CHARTS and CZMIL) over-flights between 2008−2016—complemented by ground-truth (Ponar sediment sampling, ROV photography) and passive bottom reflectance studies (3-band NAIP; 13-band Sentinal-2 orbital satellite; 48 and 288-band CASI)—clarified shoreline and underwater details of tailings migrations. Underwater, the tailings are moving onto Buffalo Reef, a major breeding site important for commercial and recreational lake trout and lake whitefish production (32% of the commercial catch in Keweenaw Bay, 22% in southern Lake Superior). If nothing is done, LiDAR-assisted hydrodynamic modeling predicts 60% tailings cover of Buffalo Reef within 10 years. Bottom reflectance studies confirmed stamp sand encroachment into cobble beds in shallow (0-5m) water but had difficulties in deeper waters (>8 m). Two substrate end-members (sand particles) showed extensive mixing but were handled by CASI hyperspectral imaging. Bottom reflectance studies suggested 25-35% tailings cover of Buffalo Reef, comparable to estimates from independent counts of mixed sand particles (ca. 35% cover of Buffalo Reef by >20% stamp sand mixtures).

【 授权许可】

Unknown