17 Dec 2014

Coupling groundwater and regional climate models

In collaboration with research partners, we developed a novel climate-hydrology modelling tool that addresses some of the important shortfalls in current climate models.

Improving our understanding of interactions between the atmosphere, land surface and subsurface hydrology plays a key role in ensuring sustainable development of water resources and terrestrial ecosystems. This becomes even more important when assessing the potential impacts of climate change on surface water and groundwater resources and the ecosystems that depend on them. 

One of the most important challenges in water-climate science is to understand how the exchange of water between atmosphere and surface and subsurface water will change in a future climate. There are two important gaps in our current knowledge. 

First, the interaction between climate and groundwater is often neglected in current climate models even though groundwater accounts for a major portion of global water resources. Second, there is a need for tools that combine climate change projections with simulations of anthropogenic effects such as:
  • changes in land use
  • the introduction of reservoirs for flood control and irrigation
  • the conjunctive use (combined use designed to minimise undesirable effects and optimise the water demand/supply balance) of surface water and groundwater
Together with the partners from the project HYdrological Modelling for Assessing Climate Change Impacts at differeNT Scales (HYACINTS), we developed a novel climate-hydrology modelling tool to address these needs. Part of the Danish Strategic Research’s HYACINTS project, the tool consists of a dynamic coupling between our hydrological modelling system MIKE SHE and the regional climate model HIRHAM developed by the Danish Meteorological Institute (DMI). 

Utilising the Open Modelling Interface (OpenMI), this tool is a first step towards an end-to-end system that simulates the interactions between the climate, surface water and groundwater systems as well as the effect of human-induced changes to the water cycle. Using this tool in a managed, groundwater-dominated catchment – the Skjern River in Denmark – has highlighted the importance of representing the interaction between groundwater and the atmosphere, via the soil and surface water, in regional climate simulations. 

The full results are available in the paper ‘Embedding complex hydrology in the regional climate system – Dynamic coupling across different modelling domains’ in Advances in Water Resources.

The integrated surface water groundwater model MIKE SHE. By linking MIKE SHE to the regional climate model HIRHAM we have developed a novel climate-hydrology modelling tool.