G³M 1.0 steady-state model output

Steady-state model output of the global gradient-based groundwater model G³M 1.0. Related to the publication in GMD "Beyond the bucket - Developing a global gradient-based groundwater model (G³M v1.0) for a global hydrological model from scratch"

Contains the following global outputs:

* hydraulic head

* surface water body to/from groundwater flows

* conductance values for surface water bodies