Modélisation mathématique de l'évolution, à long terme, des teneurs en nitrates dans la nappe aquifère des craies du Crétacé de Hesbaye (Belgique) ; Groundwater modelling of the long term evolution of the nitrate content in the Cretaceous chalky aquifer of Hesbaye (Belgium)

The Hesbaye area is located in the northeastern part of Belgium. The aquifer formations consist of chalk deposits. Groundwater provides about 80,000 m 3 d -1 . Despite 5 to 20 meters of superficial loess deposits, the groundwater quality is threatened by increasing nitrate concentrations of 0.35 mg·L -1 per year in the semi-confined part of the aquifer to 0.7 mg·L -1 in the unconfined aquifer. Presently, nitrate concentrations are between 15 and 25 mg·L -1 in the semi-confined part of the aquifer but are more than 35 mg·L -1 (reaching locally 150 mg·L -1 ) in the unconfined part that covers 95... Mehr ...