Standard survey tripod

At three locations in the Sacramento, California area, the USGS Western Remote Sensing and Visualization Center (WRSVC) has utilized tripod-mounted lidar to map the three-dimensional (3D) extent of mammal burrows and tree-root casts, which can substantially compromise the structural integrity of flood-control levees. The burrows and casts were filled with grout and/or polyurethane and then carefully excavated, exposing the network of interconnected voids. An incremental sequence of excavations followed by lidar scans enabled 3D mapping of the burrow and cast networks.

At the Deer Creek study site in Nevada County, California, the USGS Western Remote Sensing and Visualization Center (WRSVC) has utilized tripod-mounted lidar to quantify the eroded volume of mercury-contaminated sediment associated with historical gold mining from a discrete section of cutbank for three periods between 2010 and 2013. The eroded volumes were combined with laboratory analyses of mercury concentration and grain-size distribution in the sediment to estimate the amount of mercury mobilized by Deer Creek for the various periods.

At the Humbug Creek/South Yuba River study site in northern California, the USGS Western Remote Sensing and Visualization Center (WRSVC) has utilized tripod-mounted lidar to quantify the eroded and deposited volumes of mercury-contaminated sediment from 2011 to 2013. A mass balance of the measured erosion and deposition volumes provides an estimate of the amount of contaminated sediment transported below a historical high water mark.