Grand
Canyon, Arizona
This site displays many characteristics of landscapes susceptible to high
rates of erosion and sediment production: steep slopes, little vegetation
cover, loose soil and rock at the surface, and a climate of intense storms.
Sediment produced here becomes part of the load of the Colorado River.
The Virgin River carries a high sediment load. Suspended load can be seen in the turbid (muddy) water. Bed load is also being carried--previous bed load deposits are apparent in the rounded boulders on the floodplain.
The Colorado River is shown here just below Glen Canyon Dam as the river enters the Grand Canyon. In the foreground is water with a high suspended load (note the silt and sand deposit at the water’s edge). This sediment load comes from the Paria River, that enters just off the left edge of the photo. Clear water in the background has been released from Glen Canyon Dam, which traps the sediment load of the Colorado.
Density differences keep the turbid water from the Paria River and the clear water released into the Colorado from Glen Canyon Dam separate, even well below the confluence of these two water sources. The turbulence indicates high stream power capable of transporting a large sediment load.
Boulder Creek carries primarily bed load. The clear water indicates very little suspended matter. Larger rocks on the stream bed are stationary in this photo, but move episodically during larger discharge events.
These large boulders, some several meters in diameter, have all been transported as bedload during large flood events.
This gravel deposit covers the stream bed of a small tributary to the Grant River (drainage area approximately 1 square mile). The gravel was deposited in a single thunderstorm delivering several inches of rain in a few hours, June, 1991.
This is an example of an artificially straightened stream. The stream may have been channelized to: (1) prevent meandering into the valuable floodplain farmland, (2) deepen the channel and provide soil drainage for the field, and (3) provide straight flow under a highway bridge.
The Grand Canyon of the Yellowstone River is an example of a natural straight stream. Note that there is no floodplain development--all of the stream energy is used to cut the canyon deeper, not to meander back and forth.
2001 view of the artificially straightened reach of Burd Run, near the University campus.
1999 aerial view of the artificially straightened reach of Burd Run, near the University campus.
2003 aerial view of the reconstructed meanders within the same reach of Burd Run.
Aerial view of a meandering river with numerous floodplain features.
Aerial view of relatively uniform river meanders. Note this stream is also on the Cumberland Valley map on the classroom wall.
The Merced River meanders through Yosemite Valley.
A high cut bank has formed on the outside of this meander bend, with point bar deposits on the inside of the bend.
A fresh gravel deposit has been left on the point bar in a recent flood event. Note that opposite the point bar, a cut bank can be seen.
This meandering stream has recently migrate across the entire foreground of the slide. An abandoned channel can be seen in the lower right, with an extensive point bar now separating it from the present channel.
A tidal meandering stream, showing a recent cutoff meander.
Aerial view of the braided Platte River over central Nebraska. Note the many separating and reconnecting channels.
Ground view of the Platte River, a classic braided stream. Note the river is wide and shallow, with many sand bars. Sediment transport is primarily bed load.
This stream has formed a braided pattern due to the extremely large sediment load provided by deeply weathered granite in a steep landscape undergoing deforestation.
Braided streams are common below active glaciers, due to the volume of coarse sediment load and the fluctuating discharge.
A shallow braided stream with extensive sandbars. Note the local bedrock is Navajo sandstone, from which the bedload sediment is derived.
Alluvial fans are common at the base of these arid mountains.
Note the multiple, changing channels across the alluvial fans.
Here alluvial fans coalesce at the base of the Rocky Mountains.
A small delta has developed where the small, but high-energy intermittent tributary deposits its sediment load into the larger Virgin River.
The Gray's River sediment load forms a delta where it flows into the much larger Columbia River.
