Seasonal Variations in Groundwater Chemistry Near Lake Belau, Schleswig-Holstein, Northern Germany

• Published in: Hydrogeology journal 1997-02, Vol.5 (2), p.86-95
• Main Author: Scheytt, T
• Format: Article
• Language: English
• Subjects: Aquifers; Arable land; Groundwater; Lakes; Land; Magnesium; Seasonal variations; Wells
• ISSN: 1431-2174; 1435-0157
• DOI: 10.1007/s100400050123

The groundwater composition in an unconfined sandy aquifer of Quaternary age in the Bornhoeved Lakes research area, Germany, exhibits not only spatial but also temporal variability. The aquifer has a thickness of about 40 m, and the thickness of the unsaturated zone ranges from 0.5-20 m. Groundwater chemistry was studied in four multilevel wells on the west bank of Lake Belau and in one multilevel well on the east bank; these wells are situated in both arable and forested land. Groundwater from these wells has seasonal variations of physico-chemical parameters and of the concentration of groundwater constituents. Beneath arable land, large variations occur in the concentrations of potassium, calcium, magnesium, and nitrate near the water table. Beneath forested land, large variations occur seasonally in the contents of sodium, chloride, and sulfate, together with lower concentrations of nitrate. These changes are caused mainly by seasonal variations in groundwater recharge.Original Abstract: La composition de l'eau souterraine d'un aquifere non captif de sables quaternaires, etudie dans la region des lacs Bornhoeved (Allemagne), montre des variations a la fois spatiales et temporelles. L'aquifere est epais d'environ 40 m et sa zone non saturee de 0,5 a 20 m. La chimie de l'eau souterraine a eteetudiee dans quatre puits a niveaux d'eau multiples sur la rive ouest du lac Belau et dans un puits a niveaux multiples, sur la rive est. Les puits sont situes en zones de cultures et de forets. Dans ce puits, l'eau souterraine suit des variations saisonnieres des parametres physico-chimiques et des teneurs en substances dissoutes. Sous les terres cultivees, les teneurs en K, Ca, Mg et NO sub(3) varient largement, au voisinage de la surface piezometrique. Sous les forets, ce sont celles en Na, Cl et SO sub(4) qui varient, en association avec des teneurs en NO sub(3) faibles. Ces modifications sont dues essentiellement aux variations saisonnieres de la recharge de la nappe.