If you have ever tried to assign spatially variable material properties in your HGS models using raster files, you will already know that there were several different command specific to individual properties.

This post describes how to use particle tracing in HydroGeoSphere, introduced with the release of HGS revision 2385 (April 2022). This new capability allows users to track the movement of massless particles through the subsurface domain, providing valuable insights into flow patterns and transport processes. Conceptually, particle tracing helps visualize how water moves through the system, making it a powerful tool for analyzing groundwater flow and solute transport. We find this feature particularly useful for understanding complex flow dynamics.

This post describes how to use Tecplot export commands to visualize model properties and structures without running a full simulation. Commands like mesh to tecplot, K to tecplot, and channels to tecplot allow users to quickly inspect their model setup by generating Tecplot-formatted files directly from grok.exe. These commands are particularly useful for reviewing mesh structures, material properties, and domain features like fractures and channels before committing to a full model run. We find these tools extremely helpful for catching errors early and streamlining the model-building process.

This post describes the new reservoir with spillway boundary condition, an improvement over the basic reservoir BC that provides greater control over water release in HydroGeoSphere models. This boundary condition allows for more realistic reservoir inflow and outflow behavior by incorporating parameters such as surcharge storage, spillway discharge, and gate-controlled release. Conceptually, the reservoir with spillway BC enhances water management simulations by dynamically adjusting outflows based on reservoir storage conditions rather than relying solely on predefined time-value tables. We find this boundary condition particularly useful for modeling hydraulic control features in complex water management scenarios.

This post describes how to use the fluid volume concentration threshold command, introduced in the January 2022 release (revision 2342), to calculate fluid volumes throughout the model domain that exceed or fall below a user-defined concentration threshold. Conceptually, we can think of this command as a way to separate water into two categories based on solute concentration—those above the threshold (contaminated water) and those below (uncontaminated water). This command is active when the concentration value reaches the specified threshold, removing the need for post-processing in external software like Tecplot.