Geoscience Reference
In-Depth Information
Chapter 19
Potential Change in Groundwater Discharge as
Response to Varying Climatic Conditions - An
Experimental Model Study at Catchment Scale
Maria-Theresia Schafmeister and Andreas Darsow
Abstract
The possible change in groundwater discharge from a medium-scale
catchment to the Baltic is studied by means of a numerical groundwater flow model.
The test area northeast of Wismar (Mecklenburg-Vorpommern, Germany) is built by
quaternary glaciofluvial sands and intercalated tills. Today's groundwater recharge
is calculated as 24% of the recent average annual precipitation of 600 mm in the
test area, and its submarine groundwater discharge is modelled to 14.3% of the pre-
cipitation. Based on climate scenarios calculated by the Swedish Meteorological
and Hydrological Institute (SMHI) and the Hadley Centre (HC) three sea-level
scenarios in combination with four precipitation scenarios are modelled for steady-
state groundwater conditions in order to assess potential response in discharge. The
temporal development is observed in a simplified schematic model for transient
conditions. For the given conditions the influence of sea-level rise is almost not
noticeable. However, the modelled scenarios indicate that changes in groundwa-
ter recharge as a consequence of climate-induced changes in precipitation lead to
notable variations of submarine groundwater discharge.
Keywords
Hydrogeology
·
Climate change
·
Coastal aquifers
·
Submarine
discharge
·
Freshwater resources
19.1 Introduction
Climate change will undoubtedly affect the coastal regions of the Northern
hemisphere. Changes in temperature, precipitation and sea level have a strong
influence on the hydrodynamics of coastal aquifers.
At the Baltic Sea region the climate change effects are superimposed on the
isostatic crustal movement (Harff et al.
2005
). A detailed description of the effects
