SUTRA — The Complete Guide: Seawater Intrusion, Variable-Density Flow and Heat Transport
SUTRA is the USGS finite-element simulator for saturated–unsaturated, variable-density groundwater flow in 2D and 3D, coupled with solute or energy transport. Where salty seawater meets fresh groundwater, density changes the direction of flow — and that is exactly what SUTRA is built to compute. It is in the public domain, and the source code is included in the download.
SUTRA
U.S. Geological Survey (USGS)
Finite-element simulator for saturated–unsaturated, variable-density groundwater flow with solute or heat transport.
Get it from the vendorWhat you get
- Variable-density flow — the effect of salinity and temperature on flow.
- Saturated and unsaturated — in one model, with selectable saturation relations.
- Solute or heat transport — salinity, contaminants or energy.
- Freeze–thaw — a capability added in version 4.0.
- Finite-element mesh — fitting complex geometry.
Who it suits
Hydrogeologists and environmental engineers working on seawater intrusion into coastal aquifers, contaminant plumes, ground heat storage and shallow geothermal systems. The engine is driven by text files, and mesh preparation and result display rely on companion tools such as ModelMuse. The ready-made executable is for Windows only; on other systems you compile the source.
Related tools
For building a SUTRA model in a graphical interface — ModelMuse. For coupled thermo-hydro-mechanical problems — OpenGeoSys. For regional constant-density flow — MODFLOW 6.
ModelMuse
U.S. Geological Survey (USGS)
The free graphical interface to MODFLOW — build the model with a mouse instead of text files.
Get it from the vendor
OpenGeoSys
OpenGeoSys community (UFZ)
Finite element simulator for coupled thermal, hydraulic and mechanical processes in soil and rock — groundwater, geothermal, repositories.
Get it from the vendorMODFLOW 6
U.S. Geological Survey (USGS)
The world standard for groundwater flow and solute transport modelling, from the USGS.
Get it from the vendorMT3D-USGS
U.S. Geological Survey (USGS)
Groundwater solute and contaminant transport simulator driven by MODFLOW flow results.
Get it from the vendorThe bottom line
For seawater intrusion and variable-density problems, SUTRA is a long-standing, documented and completely free tool — especially when paired with ModelMuse.