Water flows down a river located in the State of Virginia.
river, stream of water larger than a brook or creek. Land surfaces are never perfectly flat, and as a result the runoff after precipitation tends to flow downward by the shortest and steepest course in depressions formed by the intersection of slopes. Runoffs of sufficient volume and velocity join to form a stream that, by the erosion of underlying earth and rock, deepens its bed; it becomes perennial when it cuts deeply enough to be fed by groundwater or when it has as its source an unlimited water reservoir, for example, the St. Lawrence flowing from the Great Lakes. The lowest level to which a river can erode its bed is called base level. Sea level is the ultimate base level, but the floor of a lake or basin into which a river flows may become a local and temporary base level. Cliffs or escarpments and differences in the resistance of rocks create irregularities in the bed of a river and can thus cause rapids and waterfalls. A river tends to eliminate irregularities and to form a smooth gradient from its source to its base level. As it approaches base level, downward cutting is replaced by lateral cutting, and the river widens its bed and valley and develops a sinuous course that forms exaggerated loops and bends called meanders. A river may open up a new channel across the arc of a meander, thereby cutting off the arc and creating an oxbow lake. Rivers modify topography by deposition as well as by erosion. River velocity determines quantity and size of rock fragments and sediment carried by the river. When the velocity is checked by changes of flow or of gradient, by meeting the water mass of lakes or oceans, or by the spreading of water when a stream overflows its banks, part of the load carried by the stream is deposited in the riverbed or beyond the channel. Landforms produced by deposition include the delta, the floodplain, the channel bar, and the alluvial fan and cone. The discharge, or rate of outflow, of a river depends on the width of its channel and
Size: 5616px × 3744px
Location: Shenandoah national forest, Madison county, virginia
Photo credit: © Andrew Shurtleff / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: algae, applied, beck, branch, brook, channel, channels., converging, creek, definite, diverging, estuary, flow, flowing, interchangeably, large, larger, lichen, natural, rill, river, rivulet, rock, rocks, run, runnel, scenic, series, size, small, smaller, stream, tributary, water, watercourse, wilderness
