Vallet Coulomb C., Gasse F., Robison L., Ferry Luc. (2006). Simulation of the water and isotopic balance of a closed tropical lake at a daily time step (Lake Ihotry, South-West of Madagascar). Journal of Geochemical Exploration, 88 (1-3 : Special Iss. SI), p. 153-156. ISSN 0375 6742.
Titre du document
Simulation of the water and isotopic balance of a closed tropical lake at a daily time step (Lake Ihotry, South-West of Madagascar)
Journal of Geochemical Exploration, 2006,
88 (1-3 : Special Iss. SI), p. 153-156 ISSN 0375 6742
Lake Ihotry is a closed lake where evaporation constitute 99% of water outputs, and where the seasonal isotopic evaporative enrichment is important (from delta O-18=-3 parts per thousand to +6 parts per thousand and from delta H-2=-20 parts per thousand to +30 parts per thousand). For a two-year measurement period, a dynamic model of lake water level leads to an accurate determination of the water balance at a daily time step. An isotopic balance model (6180 and 62 H), including the Craig and Gordon evaporation model, has been coupled with the water balance model in order to simulate the evolution of the lake water isotopic composition. We propose that the moisture buildup over the lake surface affects the isotopic balance during the seasonal isotopic enrichment. A mixture between a vapour in isotopic equilibrium with rainfall (75%) and the locally evaporated moisture (25%) provides a good simulation of the lake water isotopic composition. (c) 2005 Elsevier B.V. All rights reserved.
