NEW version of HGS PREMIUM July 2026 (REVISION 2992)
Support Ongoing Improvements to HGS
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The HydroGeoSphere July 2026 software update is now available for download.
This month’s update delivers improvements to surface water boundary conditions, transport simulations, raster handling, and solver robustness, while introducing several new commands for surface flow control, sorption modeling, and CSV output. Together, these updates improve simulation accuracy, strengthen numerical stability, and provide more flexible tools for post-processing and model configuration in HydroGeoSphere (HGS).
New CSV output commands
csv flux output nodes reports fluid flux for flow simulations and mass flux for transport simulations across a chosen set of nodes in all model domains.
csv head output nodes reports head information for selected porous medium nodes over a specified set of output times.
These commands simplify exporting model results for external analysis and visualization.
New Langmuir isotherm commands
New commands langmuir isotherm and zoned langmuir isotherm add support for defining Langmuir adsorption isotherms within the porous medium domain.
These commands expand HGS transport modeling capabilities for sorption processes.
New command impermeable surface
This new command allows users to set the fluid exchange between the surface and subsurface domains to zero according to a time on/off table for a selected group of surface faces.
This provides greater flexibility when representing temporary or controlled impermeable surface conditions.
hsplot removed from the HGS installation
With this release, hsplot has been removed from the HydroGeoSphere installation and is now officially obsolete.
Users should use hgs2vtu for all post-processing and visualization workflows going forward.
Improved performance and solver robustness
Improved the performance of the critical depth and zero depth gradient boundary conditions.
Updated raster file reading with GDAL to provide more detailed error messages when raster files cannot be opened.
Modified solver behavior so that when a "fatally small diagonal in preconditioner" error occurs, HGS now automatically restarts the current timestep using a smaller timestep instead of terminating the simulation.
This allows more simulations to recover automatically from difficult nonlinear solution conditions.
Improved boundary condition and transport calculations
Fixed a bug in the zero depth gradient boundary condition mass balance calculation caused by an incorrect bed slope value.
Fixed a bug in the Freundlich isotherm computation that occurred when concentration was zero and the exponent was less than or equal to one.
Fixed a bug that caused incorrect mass flux values to be reported by the flux output nodes and flux output nodes from chosen commands during transport simulations.
These fixes improve the reliability of both flow and transport results.
Fixes for surface domain element selection
Resolved a bug that could cause incorrect surface domain elements to be selected from a face selection when the surface domain was defined in multiple stages.
This improves the accuracy of several commands that rely on surface face selections, including fluid mass balance, polygon tracking, zone assignment, and time-varying friction.
You can find details about these new features in the HydroGeoSphere Reference Manual. And as always, we are committed to the continued improvement of the user experience. Do you have suggestions for new commands or improvements to the user experience? Send your ideas to support@aquanty.com