Valley - River Valleys

River Valleys

For a comprehensive list of world wide river valleys see: River valleys (category)
Further information: River phenomenon

A valley formed by flowing water, or river valley, is usually V-shaped. The exact shape will depend on the characteristics of the stream flowing through it. Rivers with steep gradients, as in mountain ranges, produce steep walls and a bottom. Shallower slopes may produce broader and gentler valleys, but in the lowest stretch of a river, where it approaches its base level, it begins to deposit sediment and the valley bottom becomes a floodplain.

Some broad V examples are:

  • North America: Black Canyon of the Gunnison National Park, and others in Grand Canyon NP
  • Europe:
    • Austria: narrow passages of upper Inn valley (Inntal), affluents of Enns a.s.o
    • Switzerland: Napf region, Zurich Oberland, Engadin
    • Germany: affluents to the middle reaches of Rhine and Mosel

Some of the first human complex societies originated in river valleys, such as that of the Nile, Tigris-Euphrates, Indus, Ganges, Yangtze, Huang He, Mississippi, and arguably Amazon. In prehistory, the rivers were used as a source of freshwater and food (fish and game), as well as a place to wash and a sewer. The proximity of water moderated temperature extremes and provided a source for irrigation, stimulating the development of agriculture. Most of the first civilizations developed from these river valley communities.

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Famous quotes containing the words river and/or valleys:

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    Denise Levertov (b. 1923)

    The West is preparing to add its fables to those of the East. The valleys of the Ganges, the Nile, and the Rhine having yielded their crop, it remains to be seen what the valleys of the Amazon, the Plate, the Orinoco, the St. Lawrence, and the Mississippi will produce. Perchance, when, in the course of ages, American liberty has become a fiction of the past,—as it is to some extent a fiction of the present,—the poets of the world will be inspired by American mythology.
    Henry David Thoreau (1817–1862)