What uses of piezometric network’s data in hard-rock aquifers ? Example of Brittany’s network 10 years after its implementation.

Bruno Mougin (1) , Flora Lucassou (1) , Florian Koch (1)

1 BRGM - Bureau de Recherches Géologiques et Minières

For a long time ago considered as a region devoid of big aquifers, Brittany’s region has a piezometric network since 10 years contrary to other regions equipped since the 1970s. Its implementation was financed by Loire-Bretagne Water Agency, BRGM, Regional Council of Brittany, and Regional Department for the environment. Since 2008, network’s supervision and follow-up is financed by ONEMA and BRGM. Brittany’s piezometric network is constituted by 52 boreholes equipped with automatic acquisition of water level and with data’s remote transmission. Among these points, 48 are settled in hard-rock aquifers (4 others follow alluviums or tertiary aquifers). Their location has been carefully cogitated, and it allows to cover main geological and hydrogeological formations existing in Brittany and takes into account weather conditions very contrasted from west to east and between coast and the inland. After check and validation, data are stored and put at the public’s disposal on the French national groundwater database called ADES. 10 years after its implementation, piezometric network’s basic data of Brittany are useful for various valorisations and plenty of different uses : evaluation of groundwater bodies quantitative status, bulletins of groundwater’s level situations, elaboration of indicators piezometric dedicated to the departmental management of the drinking water, contribution of groundwater to rivers flows, diagnosis of floods by water table rise, interactive dashboard… Acquired data have also allowed to better understand Brittany’s hard-rock aquifers : dynamics and slowness, cycles of data variation, memory effect, overflowing, time of water table’s drop, and blocking high levels.

Mots clés: piezometric network; hard-rock aquifers; Brittany

Domaines: Hydrologie; Géologie appliquée

Bruno Mougin, Flora Lucassou, Florian Koch. What uses of piezometric network’s data in hard-rock aquifers ? Example of Brittany’s network 10 years after its implementation.. 43rd IAH International Congress “Groundwater and society : 60 years of IAH”, Sep 2016, Montpellier, France. 2016. ⟨hal-01379203⟩