Drainage divide


Drainage divide
Main European drainage divides (red lines) separating drainage basins (gray regions)

A drainage divide, water divide, divide or (outside North America) watershed is the line separating neighbouring drainage basins (catchments). In hilly country, the divide lies along topographical peaks and ridges, and may be in the form of a single range of hills or mountains (known as a Dividing range), but in flat country (especially where the ground is marshy) the divide may be invisible – just a more or less notional line on the ground on either side of which falling raindrops will start a journey to different rivers, and even to different sides of a region or continent.

Drainage divides are important geographical, and often also political boundaries. Roads (such as ridgeways) and rail tracks often follow divides to minimise grades (gradients), and to avoid marshes and rivers.

A divide is also known as:

  • A watershed, the line between drainage basins – shedding is an old term for splitting or dividing, so it is the line which divides the water (however in North America "watershed" has come to mean the drainage basin itself);
  • a water parting;
  • a height of land (in Canada).

A valley floor divide is a low drainage divide running across a valley, sometimes created by deposition or stream capture.

Types

Drainage divides can be grouped in three types:

A divide in which the waters on each side flow to different oceans (example: the Nile and Congo divide, Lunghin Pass triple divide)
  • Major drainage divide
The waters on each side of the divide never meet again, but do flow into the same ocean (example: the divide between the Yellow River basin and the Yangtze)
  • Minor drainage divide
The waters part but eventually join again at a river confluence (example: the Mississippi and Missouri divide)

Drainage divides are a hindrance to river navigation. In pre-industrial times water divides were crossed at portages. Later, canals were built to connect the adjoining drainage basins.

See also


Wikimedia Foundation. 2010.

Look at other dictionaries:

  • drainage divide — vandenskyra statusas T sritis ekologija ir aplinkotyra apibrėžtis Dviejų upių baseinų arba dviejų jūrų, vandenynų baseinų riba. atitikmenys: angl. divide; drainage divide; water parting; watershed vok. Wasserscheide, f rus. водораздел, m …   Ekologijos terminų aiškinamasis žodynas

  • drainage divide —    The rim of a drainage basin [16].    See also divide; ground water divide; water table divide …   Lexicon of Cave and Karst Terminology

  • Drainage basin — Example of a drainage basin. The dashed line is the main water divide of the hydrographic basin A drainage basin is an extent or an area of land where surface water from rain and melting snow or ice converges to a single point, usually the exit… …   Wikipedia

  • Divide — Articles concerning Divide include: In Geography: Drainage divide or watershed, a ridge of land between two drainage basins Continental divide, a water divide between the drainage of two oceans Continental Divide, the North American divide… …   Wikipedia

  • divide —    1. A line connecting the highest topographic elevations or ground water crests that separate one drainage basin from another [16].    2. A ridge in the water table or potentiometric surface from which the ground water represented by that… …   Lexicon of Cave and Karst Terminology

  • Drainage basins of South Africa — A drainage basin is an extent of land where water from rain and melting snow or ice drains downhill into a body of water, such as a river, lake, reservoir, estuary, wetland, sea or ocean. The drainage basin includes both the streams and rivers… …   Wikipedia

  • drainage basin — the area drained by a river and all its tributaries. Also called catchment area, drainage area. Cf. watershed (def. 2). [1880 85, Amer.] * * * ▪ geology also called  Catchment Area,  or (in North America)  Watershed,      …   Universalium

  • Drainage — See also: Storm drain and Stormwater Deep inside a Sydney drain in New South Wales Drainage is the natural or artificial removal of surface and sub surface water from an area. Many agricultural soils need drainage to improv …   Wikipedia

  • drainage basin —    A general term for a region or area bounded by a drainage divide and occupied by a drainage system.    GG …   Glossary of landform and geologic terms

  • divide — vandenskyra statusas T sritis ekologija ir aplinkotyra apibrėžtis Dviejų upių baseinų arba dviejų jūrų, vandenynų baseinų riba. atitikmenys: angl. divide; drainage divide; water parting; watershed vok. Wasserscheide, f rus. водораздел, m …   Ekologijos terminų aiškinamasis žodynas


Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”

We are using cookies for the best presentation of our site. Continuing to use this site, you agree with this.