Science et changements planétaires / Sécheresse


Hydroclimatic balance of the Maharlu lake depression (Iran) Volume 14, issue 4, OCTOBRE-NOVEMBRE-DÉCEMBRE 2003


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Université J. Fourier Grenoble I, Institut de géographie alpine (IGA), 14 bis, avenue Marie‐Reynoard, 38100 Grenoble <dominique.dumasujf‐grenoble.fr> Université Jean Moulin Lyon III, CRGA‐UMR 5600, 18, rue Chevreul, 69362 Lyon Cedex 07 <mmiettonyahoo.fr> Université Louis Pasteur Strasbourg I, Faculté de géographie, 3, rue de l‘Argonne, 67000 Strasbourg <joel.humbertsentoo.sn>

In South West Iran and in a semiarid climate, the existence of the endoreic Maharlu lake is perpetuated through a subtle balance between an evaporation of about 2 m per year and an addition of rainwater which is four times less important, leading to an average water level inferior to 500 mm throughout the year. Many data that were mainly collected throughout 1988 allowed to assess the main terms of the monthly hydrological balance of the Maharlu lake and thereby to foresee the climatic evolution of these semiarid areas more precisely. This lake has probably been in existence since the Quaternary period, may be the Miocene, and its longevity is due, on the one hand, to the surface of the basin upstream (4,000 km 2) which makes for the major loss through evaporation in the hydrological balance and, on the other hand, to the huge capacity of the lake (300 to 500 millions of m 3) which allows a certain hydrological compensation in years of particular drought.