To improve our understanding of the impacts of feedback between the atmosphere and the terrestrial
water cycle including groundwater and to improve the integration of water resource management
modelling for climate adaption we have developed a dynamically coupled climate–hydrological modelling
system. The OpenMI modelling interface is used to couple a comprehensive hydrological modelling
system, MIKE SHE running on personal computers, and a regional climate modelling system, HIRHAM
running on a high performance computing platform. The coupled model enables two-way interaction
between the atmosphere and the groundwater via the land surface and can represent the lateral
movement of water in both the surface and subsurface and their interactions, not normally accounted
for in climate models. Meso-scale processes are important for climate in general and rainfall in particular.
Hydrological impacts are assessed at the catchment scale, the most important scale for water management.
Feedback between groundwater, the land surface and the atmosphere occurs across a range of
scales. Recognising this, the coupling was developed to allow dynamic exchange of water and energy
at the catchment scale embedded within a larger meso-scale modelling domain. We present the coupling
methodology used and describe the challenges in representing the exchanges between models and across
scales. The coupled model is applied to one-way and two-way coupled simulations for a managed
groundwater-dominated catchment, the Skjern River, Denmark. These coupled model simulations are
evaluated against field observations and then compared with uncoupled climate and hydrological model
simulations. Exploratory simulations show significant differences, particularly in the summer for
precipitation and evapotranspiration the coupled model including groundwater and the RCM where
groundwater is neglected. However, the resulting differences in the net precipitation and the catchment
runoff in this groundwater dominated catchment were small. The need for further decadal scale
simulations to understand the differences and insensitivity is highlighted.
© 2014 Elsevier Ltd. All rights reserved.
- Climate change
- Water resources management
- Dynamic model coupling
- Groundwater–atmosphere interaction
- Atmospheric feedback