On the parameterization of groundwater models for continental and global scales applications

Abstract:

It is urgent to quantify the effects of growing population and climate change on water resources since their scarcity will entail negative consequences for the economy, and especially, for the food production. This goal can only be reached by using numerical models at continental or global scales given the global nature of these events (i.e., growing population and climate change). Despite there is a wide range of models that allow predicting surface water dynamics, there is a gap concerning models to simulate realistically the groundwater response.

Numerous difficulties arise when developing groundwater models at regional scales, among them, the most important is the lack of data to parameterize the model. Despite the existence of some databases containing global information about the horizontal distribution of shallow materials, there are no reliable information about aquifer thicknesses or about the depths until which groundwater models should be extended.

In this context, we propose to determine the “effective transmissivity” from spectral analyses of the baseflow. The “effective transmissivity” refers to the thickness of aquifer that contributes to the baseflow, thus it represents the most “active” part of the aquifer. We compute the spatial distribution of “effective transmissivity” across Europe using information from time series of more than 4000 gauging stations. These results are then used to establish a groundwater model with an aim to predict the dynamics and distribution of shallow groundwater across Europe. In this presentation, we discuss about the challenges and potential pathways as well as present the applications of well-parameterized large-scale groundwater models in the context of global change.