Technical Service Center
Sedimentation and River Hydraulics Group
SRH-2D and SRH-W (Formerly GSTAR-W)
Both SRH-2D and SRH-W are two-dimensional (2D) depth-averaged models under development at the Sedimentation and River Hydraulics Group, Technical Service Center, Bureau of Reclamation. SRH-W is limited to fixed bed flow simulation for rivers and watersheds and is available for download; while SRH-2D is currently under development and will include the mobile bed capability with sediment transport for rivers. Its release date is unknown and is dependent on the funding availability and degree of model maturity.
About SRH-W (Formerly GSTAR-W)
SRH-W, Sedimentation and River Hydraulic – Watershed model, is a two-dimensional (2D) hydraulic and run-off model suitable for either river system modeling or watershed modeling. SRH-W is a research code that is subject to continuous development. SRH-W is mainly developed for Reclamation internal use, but SRH-W version 1.1 is now released as it is deemed to benefit the public.
SRH-W is the 2D model for hydraulic flow simulation only, for river flows or watershed run-off, without the sedimentation capability. SRH-W solves the 2D dynamic wave equations, the standard depth-averaged St. Venant shallow water equations, for river simulation. In addition, the diffusive wave solver is also offered for watershed runoff simulation. SRH-W is comparable to a number of existing models such as RMA-2 and MIKE21 in its river simulation capability, but with a flexible meshing method and easy-to-run feature. For watershed applications, SRH-W is a distributed model for the event-based runoff simulation and has capabilities similar to CASC2D.
View the 2006 FISC Short Course Presentation for a quick overview of GSTAR-W v1.
Major Features of SRH-W
SRH-W adopts an unstructured mesh with arbitrarily shaped cells for geometry representation. It essentially allows the use of most existing meshing methods available: Cartesian mesh, boundary fitted structured mesh, triangular finite element mesh, or hybrid mesh with a combination of quadrilateral and triangular cells. In most applications, a combination of quadrilateral and triangular meshes works the best. See the User’s Manual for samples of such hybrid meshes.
A list of major features of SRH-W is as follows:
- SRH-W solves the 2D depth-averaged form of the diffusive wave or the dynamic wave equations. The dynamic wave equations are the standard St. Venant depth-averaged shallow water equations;
- Both the diffusive wave and dynamic wave solvers use the implicit scheme to achieve solution robustness and efficiency;
- Both steady or unsteady flows may be simulated;
- All flow regimes, i.e., subcritical, transcritical, and supercritical flows, may be simulated simultaneously without the need of a special treatment;
- Solution domain may include a combination of main channels, side channels, floodplains, and overland;
- Solved variables include water surface elevation, water depth, and depth averaged velocity. Output information includes above variables, plus flow inundation, Froude number, and bed shear stress.
SRH-W is a 2D model and it is particularly useful for problems where 2D effects are important. Examples include flows with in-stream structures, through bends, with perched rivers, with multiple channel systems, and with complex floodplains. A 2D model may also be needed if one is interested in local flow velocities, eddy patterns and flow recirculation, lateral variations, flow spills over banks and levees, and flow diversion and bifurcation.
Downloads
- SRH-W Theory and User's Manual (11.5 MB pdf)
- SRH-W v1.1 Distribution Package: Software, Manual, and Tutorials (11.9 MB zip)
- Projects, Presentations, and Reports
- FISC 2006 Short Course Presentation (9.8MB pdf)
- FISC Watershed Modeling Paper, 2006 (779 kB pdf)
- FISC 2006 Savage Rapids Paper
- Final Report for Savage Rapids Dam Removal, 2006
- Final Report for Sandy River, 2006
- US-China Workshop, 2005 (670kB pdf)
Contact
For comments and your application story on SRH-W, contact Yong Lai through e-mail at ylai@do.usbr.gov. But note that Reclamation does not provide technical support for use of the software. Please read the Disclaimer in the User’s Manual for details.