DI-UMONS : Dépôt institutionnel de l’université de Mons

Recherche transversale
(titres de publication, de périodique et noms de colloque inclus)
2021-09-09 - Colloque/Présentation - communication orale - Anglais - page(s)

Picot-Colbeaux Géraldine, Vandelois Guillaume , Bouvet Aurélie, Parmentier Marc, Canlers Olivier, Masset Roland, Verlé Wendy, Blondel Laurence, Euverte Cyril, Rorive Alain , Goderniaux Pascal , "Regional groundwater systems and transboundary aquifers: Carboniferous limestone transboundary aquifer case (Belgium/France)." in 48th IAH Congress, Brussels, Belgium, 2021

  • Codes CREF : Hydrogéologie (DI1426)
  • Unités de recherche UMONS : Géologie fondamentale et appliquée (F401)
  • Instituts UMONS : Institut des Sciences et du Management des Risques (Risques), Institut de Recherche en Energétique (Energie)

Abstract(s) :

(Anglais) Regional groundwater systems and transboundary aquifers: Carboniferous limestone transboundary aquifer case (Belgium/France). Géraldine PICOT-COLBEAUX1*, Guillaume VANDELOIS2, Aurélie BOUVET-SWIALKOWSKI3, Marc PARMENTIER4, Olivier CANLERS5, Roland MASSET6, Wendy VERLÉ7, Laurence BLONDEL3, Cyrille EUVERTE8, Alain RORIVE2, Pascal GODERNIAUX2 1 BRGM, French Geological Survey, Orléans, France 2 Geology and Applied Geology, University of Mons, Mons, Belgium 3MEL, Lille, France 4 BRGM, French Geological Survey, Lesquin, France 5 DREAL, Hauts-de-France, Lille, France 6 SPW - Direction des Eaux souterraines du Service Public de Wallonie, Liège, Belgium 7 VMM - Vlaamse MilieuMaatschappij – the Flanders Enviroment Agency, Aalst, Belgium 8 Agence de l’Eau Artois-Picardie, Douai, France * g.picot@brgm.fr Abstract The carboniferous aquifer of the international hydrographic district of the Scheldt river extends across three regions: France, Wallonia (South Belgium), Flanders (North Belgium) covering 1420 km² (Figure 1). More than 75 million cubic meters of water are pumped every year in this aquifer for drinking water distribution, agriculture, industry, and quarry dewatering. Stresses on groundwater resources in the aquifer are therefore important and pumping operations need to be managed adequately. Groundwater levels have been decreasing significantly due to the overexploitation of the aquifer caused by the industrial and demographic development of the region during the 20th century. In some area the piezometric level has dropped by 90 meters between 1910 and 2010. The aquifer is mainly composed of fractured carboniferous limestone. The aquifer is considered as unconfined in the east and confine below marls and chalk in the northwest area. Recharge is thus mainly observed within the unconfined area, with important groundwater transfers to the confined area. Groundwater flow in the aquifer has been modelled in 3D using the finite volume calculation code MARTHE, in collaboration between the different involved entities, and using data officially exchanged between administrations. The model has been calibrated for the 1900-2017 period considering abstracted groundwater volumes, recharge calculated from precipitation and evapotranspiration data, observed piezometric levels and river flow rates, collected or reconstructed since 1900. The model is used for predictive purpose. Simulations are performed on the 2020-2050 period following several scenarios including the possible evolution of groundwater abstraction as function of the demographic and economic development of the region, climate evolution and related groundwater recharge change in the evolution of dewatering operations in stone quarries. Sensitivity analysis of groundwater levels were also performed according to the location of pumping wells and others according to different climate scenarios. All these simulations constitute a scientific support for the decision-makers of each party involved which will ensure coordinated actions for a future “good state” and sustainable management of the aquifer, considering anthropic pressures and climate change. Figure 1 : Modelled area of the transboundary Carboniferous aquifer across Belgium and France. The four colored areas correspond to different administrative groundwater bodies.