So far, for regional and global climate studies most land surface models make use of a conceptual hydrological representation. As such, these models do not specifically define the interactions between the different hydrological states within a given model grid cell (i.e. hillslope, riparian zones, wetlands) as well as the lateral exchange between grid cells.
We present a new pseudo three-dimensional (3-D) framework that is able to simulate the lateral exchange of water between hillslopes, the riparian zone, wetlands, the channel network, within a given model grid cell, and across cells. Instead of applying the traditional conceptual approach, the interaction within and between the different hydrological components was incorporated using a physically based approach based on much finer resolution pixels (e.g., 1 km) than the parent regional/global climate model grid cells.
The newly developed framework proposes a compromise between the ability to accurately simulate high resolution hydrological processes and the current computational constraints. As such, our framework can be used for high-resolution land surface modeling (~1km2) but can also flexibly scales to lower resolutions.
In this presentation, we will discuss this new framework and its preliminary evaluation over a watershed in comparison with various land surface models.