Mountain

Articles

• Water balance
  26 October 2005, by F.D.-D.

  Water balance is assessed for a given place and a given period of time by comparing water inputs and outputs in that place and during that period. The assessment also takes into account the existing supply of stocks and future appropriation of these stocks. Water inputs are brought by precipitation. Outputs are from the combination of evaporation and the transpiration of plants, called evapotranspiration. Both quantities are estimated in terms of the amount of water per surface unit, but (...)

• Relief
  16 May 2012, by M. R.

  The relief of a region can be defined, as a first approximation, as the different forms, or the salient and hollow volumes that make it up - "a family of topographical forms" in the phrase of De Martonne. However, while relief is a geographical object that has been widely studied, analysed and interpreted by generations of specialists, explorers and geographers, it has not often been precisely "defined". This is probably because the notion of relief includes one of the most obvious (...)

• Altitudinal zonation
  5 October 2005, by B. E.

  The notion of altitudinal zonation is used to account for the discontinuities associated with altitude in mountain areas. It has been the subject of many iconographic representations, the principal ones generally taking the form of diagram-blocks and sections. Botanists were the first to define the working mechanisms of altitudinal zonation in mountain areas. The criteria applied to vegetation belong to physiognomy and phyto-geography (C. Troll). The altitudinal zonation of vegetation (...)

• Drainage Basin
  24 June 2010, by L.T.

  In the wide sense, a drainage basin is a portion of space drained towards an outlet by way of a system of slopes; in the strict sense the drainage basin is the elementary portion of space made up of a topographical feature or features enabling drainage towards an outlet. The origin of the concept of the drainage basin (bassin versant in French) can be found with P.Buache, Louis XIVth’s official geographer, in his notion of the "river basin" (bassin de fleuve). The scholars of the time (...)

• Mountain
  29 September 2005, by B. E.

  Attempts to provide a general and universal definition of a mountain either become bogged down in vagueness (a mass rising above the surrounding lands) or run into multiple exceptions (high plateaux, island volcanism) whenever slope and altitude are considered separately. Definitions of an administrative type emphasise limits (thresholds) (the French ‘Mountain’ law of 1985 stipulating an average municipal altitude above 700 metres and a slope steeper than 20%), as well as the (...)