Journal des sciences de la Terre et du changement climatique

Abstrait

Impact of Ponds on Local Climate: A Remote Sensing and GIS Contribution Application to the Ponds of Brenne (France)

Nedjai R, Azaroual A, Chlif K, Bensaid A, Al-Sayah M and Ysbaa L

The influence of climate change on water bodies, particularly large ones, has been the subject of numerous studies that have demonstrated significant modifications or disturbances of the hydrological cycle (lower water volumes, higher temperatures and disruption of thermal stratification, increased direct evaporation), either by interpretation of sedimentary records or by direct measurements. However, at the scale of small limnic entities, these changes are barely noticeable and are only translated by a mere human reflection of increased freshness and densification of fog masses in limnic areas. The results of direct field measurements carried out in the Brenne study sites coupled to indirect methods for surface temperature estimation (remote sensing) converge to indicate either a rise of a several degrees (4-5°C) on and around the water bodies during winter periods or a decrease in summer. The magnitude of these thermal anomalies increases in areas characterized by a high density of ponds, giving these areas a distinct characteristic climatic context. The thermal envelopes change according to the seasons and the types of weather and may at times exceed 100 m to 200 m of extension around the water bodies giving rise to a particular climatic atmosphere. The proximity of the ponds in Brenne and their density give the area a climatic character translated by weather types very different from its surrounding and neighboring regions. Due to their effect the oceanic climate character is locally masked at times and during periods of high thermal contrast.