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Article dans une revue
The response of small and shallow lakes to climate change: new insights from hindcast modelling
Abstract : Small and shallow lakes represent the majority of inland freshwater bodies. However, the effects of climate change
on such ecosystems have rarely been quantitatively addressed. We propose a methodology to evaluate the thermal response
of small and shallow lakes to long-term changes in the meteorological conditions, through model simulations. To do so, a
3D thermal-hydrodynamic model is forced with meteorological data and used to hindcast the evolution of a urban lake in
the Paris region between 1960 and 2017. Its thermal response is assessed through a series of indices describing its thermal
regime in terms of water temperature, thermal stratification and potential cyanobacteria production. These indices and the
meteorological forcing are first analysed over time to test the presence of long-term monotonic trends. 3D simulations are then
exploited to highlight the presence of spatial heterogeneity. The analyses show that climate change has strongly impacted the
thermal regime of the study site. Its response is highly correlated with three meteorological variables: air temperature, solar
radiation and wind speed. Mean annual water temperature shows a considerable warming trend of 0.6°C/dec, accompanied
by longer stratification and by an increase of thermal energy favourable to cyanobacteria proliferation. The strengthening of
thermal conditions favourable for cyanobacteria is particularly strong during spring and summer, while stratification increases
especially during spring and autumn. The 3D analysis allows to detect a sharp separation between deeper and shallower portions
of the basin in terms of stratification dynamics and potential cyanobacteria production. It leads to the development over time of some areas in the study site that are particularly favourable to cyanobacteria growth and bloom initiation.
https://hal-enpc.archives-ouvertes.fr/hal-03116508
Contributeur : Brigitte Vinçon-Leite <>
Soumis le : mercredi 20 janvier 2021 - 13:05:58
Dernière modification le : mardi 2 mars 2021 - 15:23:05
Contributeur : Brigitte Vinçon-Leite <>
Soumis le : mercredi 20 janvier 2021 - 13:05:58
Dernière modification le : mardi 2 mars 2021 - 15:23:05
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