Modeling the critical zone is a challenging task, due to the huge amount of interactions between all CZ compartments.

Recent developments in the critical zone models allow coupled simulation of the different CZ compartments following state-of-the art physics of different processes. Among these models, some of them are called hyperresolution models because they allow the simulation of large domains (up to the global scale), by keeping relatively high resolution. ParFlow-CLM is one of them.

A ParFlow-CLM simulation of a small watershed in norhern Benin (West-Africa), showing the intermittent streamflow generation (surface saturation as blue patches), saturation variations in the surface and unsaturated zone, and both permanent and perched water table changes (saturated, deep blue zones in the bottom of the domain) as a response of the interplay between precipitation (spatially uniform, temporally variable) and evapotranspiration (different vegetation classes across the domain).