Also known as
Model type Modular
Model part of larger framework
Note on status model
Date note status model
Spatial dimensions 1.5D, 2D
Spatial extent Watershed-Scale
Model domain Hydrology, Terrestrial
One-line model description Coupled distributed engineering hydrology, sediment, contaminant fate/transport
Extended model description Gridded Surface Subsurface Hydrologic Analysis (GSSHA) is a grid-based two-dimensional hydrologic model. Features include 2D overland flow, 1D stream flow, 1D infiltration, 2D groundwater, and full coupling between the groundwater, vadoze zone, streams, and overland flow. GSSHA can run in both single event and long-term modes. The fully coupled groundwater to surfacewater interaction allows GSSHA to model both Hortonian and Non-Hortonian basins.

New features of version 2.0 include support for small lakes and detention basins, wetlands, improved sediment transport, and an improved stream flow model. GSSHA has been successfully used to predict soil moistures as well as runoff and flooding.


Hydrological model, basin,

Name Fred Ogden
Type of contact Model developer
Institute / Organization University of Wyoming
Postal address 1 1000 E. Univ. Ave
Postal address 2 Dept. of Civil & Architectural Engineering
Town / City Laramie
Postal code 82071
State Wyoming
Country United States
Email address
Phone 307-766-6171
Fax 307-766-2221

Name Charles Downer
Type of contact Model developer
Institute / Organization
Postal address 1
Postal address 2
Town / City
Postal code
Email address

Name Aaron Byrd
Type of contact Technical contact
Institute / Organization U.S. Army Corps of Engineers
Postal address 1 3909 Halls Ferry Rd.
Postal address 2
Town / City Vicksburg
Postal code 39180
State Mississippi
Email address
Phone 6016342473

Supported platforms
Unix, Linux, Mac OS, Windows
Other platform
Programming language


Other program language
Code optimized Single Processor, Multiple Processors
Multiple processors implemented
Nr of distributed processors
Nr of shared processors
Start year development 1988
Does model development still take place? Yes
If above answer is no, provide end year model development
Code development status
When did you indicate the 'code development status'?
Model availability As code, As teaching tool
Source code availability
(Or provide future intension)
Source web address
Source csdms web address
Program license type Other
Program license type other --
Memory requirements Depends on catchment
Typical run time depends on catchment size and process algorithms selected

Describe input parameters DEM, land-use/land-cover, stream channels, precipitation, soils, aquifer maps. These index maps are used to classify catchment parameters related to overland/channel flow, soil/aquifer hydraulic properties, soil erodibility, contaminant loadings, etc. Model setup is greatly enhanced by the use of the US Dept. of Defense Watershed Modeling System (WMS), which serves as an interface between GSSHA and Arc/Info
Input format ASCII, Binary
Other input format US Dept. of Defense Watershed Modeling System (WMS)
Describe output parameters Flow rates, depths, soil moisture, sediment fluxes, erosion/deposition, contaminant/nutrient fluxes and concentrations, groundwater levels, reservoir storages.
Output format ASCII, Binary
Other output format US Dept. of Defense Watershed Modeling System (WMS)
Pre-processing software needed? No
Describe pre-processing software
Post-processing software needed? Yes
Describe post-processing software yes, The US Dept. of Defense Watershed Modeling system can produce animations of model outputs. Run summary file includes detailed mass balance information. Output time series can be analyzed using spreadsheet or other software.
Visualization software needed? Yes
If above answer is yes
Other visualization software Dept. of Defense, Watershed Modeling System (WMS)

Describe processes represented by the model Processes:
  • Rainfall: gage with nearest neighbor or inverse distance-squared weighting, radar.
  • Interception: empirical model.
  • Infiltration: Green & Ampt, Green & Ampt with redistribution, three-layer Green & Ampt, or Richard's equation.
  • Overland runoff: 2-D finite volume diffusive wave with overland flow dykes and pothole lakes.
  • Channel routing: 1-D dendritic finite-volume diffusive wave with culverts, on-channel lakes, rule curves, rating curves, scheduled releases.
  • Groundwater: 2-D finite-difference with wells and various boundary conditions.
  • Overland erosion: three alternative source equations, raindrop impact, erosion limits, deposition, arbitrary size classes.
  • Channel sediment transport: advection-diffusion for fines, stream power for sands.
  • Fate and transport of conservative and non-conservative

constituents in soil, overland, and channels

Describe key physical parameters and equations Too much to describe in only 500 characters! See:
Describe length scale and resolution constraints Dependent upon computational power and memory.
Describe time scale and resolution constraints Dependent upon computational power and memory.
Describe any numerical limitations and issues Explicit finite volume routing formulations are time-step limited.

Describe available calibration data sets
Upload calibration data sets if available:
Describe available test data sets
Upload test data sets if available:
Describe ideal data for testing

Do you have current or future plans for collaborating with other researchers? The development of GSSHA has been funded by the US Army Corps of Engineers, Engineer Research and Development Center, Vicksburg, Mississippi. GSSHA is being actively used by a number of US Army Corps of Engineers districts.
Is there a manual available? Yes
Upload manual if available:
Model website if any
Model forum / discussion board
Comments Current version is 5.0

This part will be filled out by CSDMS staff

OpenMI compliant No but possible
BMI compliant No but possible
WMT component No but possible
PyMT component
Is this a data component
Can be coupled with:
Model info
Fred Ogden
Downer, Byrd
Nr. of publications: --
Total citations: 0
h-index: --"--" is not a number.
m-quotient: 0

Link to this page

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Input Files

Output Files