High water levels and heavy wave action have degraded shoreline, beaches, and infrastructure along the Lake Superior side of the Minnesota Point barrier island, located between the Duluth and Superior Harbor entries. The U.S. Army Corps of Engineers (USACE) has been exploring the beneficial use of dredge material for beach nourishment on the barrier island to slow the impact of erosion.
Sound (sonar or acoustic)
As part of a broader trial of noninvasive methods to research wild wolves (Canis lupus) in the Superior National Forest (SNF), Minnesota, the USGS Wolf and Deer Project (Northern Prairie Wildlife Research Center) explored whether wolves could be remotely monitored using a new, inexpensive (approximately $80 USD in 2019), remotely deployable, passive acoustic recording device.
To support the modeling of the Colorado River water storage area capacity tables by the USGS Utah Water Science Center, the USGS Earth Resources Observation and Science (EROS) Center created a three-dimensional (3D) high-resolution topobathymetric digital elevation model (TBDEM) for Lake Powell, the second largest man-made reservoir in the United States.
In preparation for the anticipated removal of four large dams from the Klamath River on the California coast, the USGS has begun a multi-year, intensive monitoring program to document the effects that dam removal will have on the river system.
The USGS Upper Midwest Environmental Sciences Center (UMESC) participated in a small subsection of a larger scope of work for the U.S. Army Corps of Engineers (USACE) led by staff at the University of Wisconsin-La Crosse and the USGS Upper Midwest Water Science Center.
Documenting bird and bat migration is challenging because migration activity is typically sporadic in nature and nocturnal movements are difficult to observe. The FWS uses avian radar to monitor the timing, duration, and activity patterns of bird and bat migrations along the shorelines of the Great Lakes (http://www.fws.gov/radar/). In fall 2015 and spring 2016, radar units were deployed in northern Michigan along Lake Huron.
Changes in sandbar geometry were mapped using historcal and recent aerial imagery to quantify the extent of sandbar encroachment into the water intake structure of the pumping plant for the Buford-Trenton Irrigation District, Williams County, North Dakota. Nine sets of aerial imagery spanning over 60 years and rectified plats from the original 1893 U.S. Geological Survey (USGS) data were used to study changes in the Missouri River extent and course.
Sound navigation and ranging (sonar) data were coupled with historical topographic data to map the extent and volume of silt collected behind the Heart Butte Dam reservoir in southwestern North Dakota. An elevation raster of the land surface submerged beneath the dam was created using sonar with 1–foot (0.3-m) depth intervals collected by the North Dakota Game & Fish Department. To depict the landscape before the dam was created, pre-dam contour and river lines were derived from a historical topographic map obtained from the U.S.
One problem with using divers or remotely operated vehicles to perform underwater inspections of hydraulic structures is that frequently-encountered conditions of poor visibility increase the inspection time and reduce the inspection quality. Commercially available scanning sonar systems can be used to overcome this limitation because sonar works in even highly turbid water to produce detailed images of underwater infrastructure. Scanning sonar can also collect survey-grade bathymetry and three-dimensional (3D) point clouds of underwater features.
Documenting bird and bat migration is challenging because of the typically sporadic nature of migration activity and the difficulty of observing nocturnal movements.