Surface to Groundwater Interactions beneath the City of Berlin: Results from 3D Models

Figure 5

Upper and lower hydraulic and thermal boundary conditions (BCs). (a) Upper hydraulic BC as derived solely from measured groundwater levels (GWLs, location of input data indicated by black dots), utilized for Model 1. (b) Upper hydraulic BC as derived from measured GWL and DEM topographical data along with river level measurements, utilized for Model 2 (GWLs + lake surfaces) and model 3 (GWLs + lake surfaces + river surface); major differences are found where surface water bodies are located. (a, b) Shaded areas represent above average hydraulic gradient (). (c) Upper thermal BC viewed in 3D, derived from temperature measurements reaching from +90 m.a.s.l. to -100 m.a.s.l., interpolated in 3D after the inverse distance weighted method; after Frick et al. [9]. (d) Lower thermal BC as extracted from a purely conductive lithosphere-scale model of the area at -6000 m.a.s.l. [9]; coordinates are in Gauß-Krüger DHDN Zone 4.

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