Calibration of a regional groundwater flow model using environmental isotope data

A steady-state two-dimensional groundwater flow and transport model of a fractured carbonate aquifer in central Württemberg (southwest Germany) was used to study the feasibility of applying stable isotopes in model calibration and to define the capture zone of the mineral springs in Stuttgart-Bad Cannstatt. Differences in the stable isotope composition of 18O and 2H in the groundwater caused by variations in altitude, were determined to be approximately 0.4[permil] [dgr ]18O per 100 m within the study area. They allow the verification of the underlying numerical flow model. The area of the capture zone is "independe- nt" of transmissivities and recharge rates as long as both are coupled to each other by calibration on the basis of measured heads. Within the possible bandwidths of transmissivities and recharge rates, linear variations of these parameters will still yield the same head distribution but different discharge rates for the springs (the discharge rate is not exactly known). The distribution of the isotopic composition and the capture zone remain unchanged.

Accès au document

Métadonnées du document