Basel City. Photo Jannis Epting.

Basel City. Photo Jannis Epting.

 

The Basel region, which borders both Germany and France, is one of the most dynamic economic regions in Switzerland and acts as a vital regional as well as interregional traffic junction. Moreover, Basel has a variety of natural environments, as well as highly vulnerable groundwater systems in river valleys and adjacent karstified areas.  Environmental changes include the development of subsurface infrastructure (e.g. tunnel highways) and urban subsurface structures, which in general, permanently impact groundwater flow and thermal regimes.  The existence of evaporites and mixtures of marl-bearing evaporites in the Triassic formations as well as the fact that Basel is located in the seismologically most active area of central Europe comes along with the potential occurrence of geohazards. Some of these hazards are natural; others are triggered by human activities.

In the last ten years these sites have been equipped with extensive groundwater monitoring systems. At the same time high-resolution geological and hydrogeological models were set up and calibrated with long-term datasets that allow comprehensive investigations of subsurface resources, groundwater flow regimes and the description of relevant boundary fluxes. The models have predictive capabilities and have already been successfully used for scenario development. These already existing tools provide substantial contributions to the understanding of hydrogeological processes and are the basis for hypothesis testing.

The Basel area includes a series of important local and regional scale water supplies, several floodplains in densely populated river valleys, as the floodplains of the Birs River (12km2) and the Wiese River (6km2) as well as the heavily industrialized area in the floodplain of the Rhine River (64km2). All sites represent important groundwater production areas in park-like natural recreation environments, surrounded by urban agglomeration, industry, contaminated sites and traffic. Drinking water supply competes with other interests or demands such as river training, flood control, recreation as well as urbanization and changes of land-use. The existence of evaporites and mixtures of marl-bearing evaporites in the Triassic formations as well as the fact that Basel is located in the seismologically most active area of central Europe comes along with the potential occurrence of geohazards. Some of these hazards are natural; others are triggered by human activities.

In the last ten years these sites have been equipped with extensive groundwater monitoring systems. At the same time high-resolution geological and hydrogeological models were set up and calibrated with long-term datasets that allow comprehensive investigations of subsurface resources, groundwater flow regimes and the description of relevant boundary fluxes. The models have predictive capabilities and have already been successfully used for scenario development. These already existing tools provide substantial contributions to the understanding of hydrogeological processes and are the basis for hypothesis testing. 

Read the Basel City Case report TU1206 WG1-017

City facts:

  • Population: ca. 175.000
  • Size: 23 square km
  • Key city issues: e.g. Flooding, Heat Pumps, Contaminated land etc