The Representation of Groundwater in Land Surface Models

The representation of groundwater in land surface models is receiving greatly increased attention in recent years. In this presentation, the evolution of its representation is discussed. The differing perspectives of what groundwater means to an atmospheric scientist versus a hydrologist are reviewed, as are concepts for its parameterization. The importance of groundwater to land-atmosphere interactions is assessed from the viewpoint of both observations and simulations. The case is made for continued enhancement of groundwater representation in several key areas, including realistic pumping rates, improved definition of aquifer boundaries, groundwater model calibration, and better ties to emerging regional and global groundwater monitoring networks.