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La sécheresse dans la France de l’Ouest : une contrainte climatique trop souvent oubliée Volume 8, issue 1, Mars 1997

Author
COSTEL, UMR 6554 CNRS, Université de Rennes 2, 6, avenue Gaston-Berger, 35043 Rennes cedex, France
  • Page(s) : 47-55
  • Published in: 1997

Water balances calculated for all stations in western France highlight a clear risk of drought occurring in summer. Although on average this constraint seems relatively unimportant, the high interannual variability in the evaporation deficiency (difference between the Turc potential evapotranspiration and actual evapotranspiration values) more accurately depicts this phenomenon, thus qualifying the usual «continuously wet» image of these oceanic regions. Moreover, there is marked spatial diversity, from the high rainy hills to the southern and eastern dry basins (Anjou, Rennes). The main rural activities (maize and pasturing) were seriously affected during the droughts of 1989 and 1990. This could be an increasingly important problem for these regions if, as indicated by most global change scenarios and a study on August precipitation, the increased summer water deficit is confirmed in the future.