Gestion des grands plans d'eau naturels. Efficacité des estimations hydrologiques à validations complémentaires. Cas des bilans journaliers du lac de Grand-Lieu, Loire-Atlantique

Management of natural large lakes. Efficiency of hydrological estimations by complementary validation. Case study of the daily water balance of Grand-Lieu Lake (France, Loire-Atlantique)

CEMAGRE Lyon Division "Hydrologie-Hydraulique" - 3 bis, quai Chauveau, 69336 Lyon Cedex 09

Abstract

The hydrological study of the lake Grand-Lieu, proves (among other results) the essential role played by the hydrometeorological data, mesured at least in some discarded points in study area, both for the modelling of the basin's outflows as well as for the lake water balance. * The simulation of the lake inflows was validated by two different ways: a conceptual model (upstreaming model) and a descriptive synthetic model (downstreaming model). * In the present paper we are giving only the modelling results of the basin's outflows and the lake water balance simulations. This step is an unavoidable one before any objective choice of an efficient water-Iake management policy.