I am new to OGS and would like to understand better the functionality of OpenGeosys. Can it simulate the runoff process (flooding) within a watershed (including both surface and subsurface runoff) and generate hydrograph at the watershed outlet? Does it include overland flow and channel flow components for conducting fully physically based modeling? I am looking for tools to simulate coupled surface-subsurface runoff and think OGS may have good potential for that.
Some years ago, in previous versions of OpenGeoSys (OGS-5 and earlier), it was possible to simulate coupled groundwater flow and surface runoff using the shallow wave equation. This allowed for a fully coupled representation of both overland and subsurface flow processes. However, in OGS6, this functionality has not been implemented, as no dedicated development team has taken on this task.
At the Helmholtz Centre for Environmental Research (UFZ), current developments focus on the coupling of OGS with mHM (the mesoscale hydrological model). This approach is particularly suited for large-scale hydrological applications, where the emphasis is on long-term water fluxes and hydrological dynamics rather than detailed water level variations. The goal is to improve process-based simulations of groundwater recharge, baseflow contributions, and interactions between surface and subsurface hydrology at the mesoscale, rather than resolving fine-scale overland flow and channel hydraulics.
For more details on OGS and its capabilities, you may find the following resources useful: