Also known as
Model type Modular
Model part of larger framework
Note on status model
Date note status model
Incorporated models or components:
Spatial dimensions 2D
Spatial extent Watershed-Scale
Model domain Terrestrial, Hydrology
One-line model description Regional Hydro-Ecologic Simulation System
Extended model description RHESSys is a GIS-based, hydro-ecological modelling framework designed to simulate carbon, water, and nutrient fluxes. By combining a set of physically-based process models and a methodology for partitioning and parameterizing the landscape, RHESSys is capable of modelling the spatial distribution and spatio-temporal interactions between different processes at the watershed scale.

biogeochemistry, water quality, C-cycle, Carbon, Nutrient cycle,

Name christina Tague
Type of contact Model developer
Institute / Organization University of California, Santa Barbara
Postal address 1 Bren Hall 4516
Postal address 2
Town / City Santa Barbara
Postal code 93106
State California
Country United States
Email address
Phone 805-893-8579
Fax 805-893-7612

Name Janet Choate
Type of contact Model developer
Institute / Organization University of California, Santa Barbara
Postal address 1 Bren Hall 4516
Postal address 2
Town / City Santa Barbara
Postal code 93106
State California
Country United States
Email address

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


Other program language
Code optimized Single Processor
Multiple processors implemented
Nr of distributed processors
Nr of shared processors
Start year development 1991
Does model development still take place? Yes
If above answer is no, provide end year model development
Code development status Active
When did you indicate the 'code development status'? 2020
Model availability As code
Source code availability
(Or provide future intension)
Through web repository
Source web address
Source csdms web address
Program license type Other
Program license type other NOT SURE
Memory requirements --
Typical run time --

Describe input parameters Input Data needed: required and optional (based on project needs and data availability):

Spatial data (GIS maps) - to be brought into GRASS GIS Basic requirements:

  • DEM (Digital Elevation Model)


  • Stream network, stream gage locations
  • Meteorological station locations
  • Vegetation and soil type, LAI
  • Road network, landcover/landuse (eg. residential, agricultural, open space, etc...)
  • Snow redistribution

Timeseries data - natural and human induced inputs as text files: Basic requirements:

  • Daily Precipitation (Meters)
  • Daily Maximum Temperature (°C)
  • Daily Minimum Temperature (°C)


  • Day length (seconds)
  • Duration of rainfall (hours)
  • Zone and seasonal scaling of LAI (unitless)
  • Incoming longwave radiation (KJ/(meters2)/day)
  • Incoming direct shortwave radiation (KJ/(meters2)/day)
  • Incoming diffuse shortwave radiation (KJ/(meters2)/day)
  • Nitrogen deposition as NO3 (kg/(meters2)/day)
  • Nitrogen deposition as NH4 (kg/(meters2)/day)
  • Incoming direct PAR radiation (KJ/(meters2)/day)
  • Incoming diffuse PAR radiation (KJ/(meters2)/day)
  • Relative humidity (Range (0-1))
  • Mean daytime temperature (°C)
  • Night time temperature at sundown (°C)
  • Soil temperature (°C)
  • Vapour pressure deficit (Pa)
  • Wind speed (meters/sec)
  • Carbon dioxide (CO2) (parts per million/year)
Input format ASCII, Binary
Other input format
Describe output parameters --
Output format ASCII, Binary
Other output format
Pre-processing software needed? Yes
Describe pre-processing software Associated with the RHESSys simulation are a number of interface programs which organize input data into the format required by the RHESSys simulation model. These include a standard GIS-based terrain partitioning program, r.watershed, and other basic GIS routines as part of the GRASS GIS system and two RHESSys specific programs:
  1. GRASS2WORLD (derives landscape representation from GIS images)
  2. CREATE_FLOWPATHS (establishes connectivity between spatial units)
Post-processing software needed? Yes
Describe post-processing software Converting RHESSys Output to Spatial Output Using rh

rh is a command line program developed to convert RHESSys model output to spatial output. The spatial output can be formatted for viewing in either GRASS or ArcView.

Requirements rh must be run from inside the GRASS GIS system. To run rh the user must first output the patch map layer into either an ascii text file for GRASS or an ascii text file for Arc/INFO or ArcView.

Visualization software needed? Yes
If above answer is yes ESRI
Other visualization software GRASS

Describe processes represented by the model The original process models include the following:
  • The MTN-Clim model (Running et al, 1987) uses topography and user supplied base station information to derive spatially variable climate variables such as radiation and to extrapolate input climate variables over topographically varying terrain.
  • An ecophysiological model is adapted from BIOME-BGC (Running and Coughlan, 1988; Running and Hunt, 1993) to estimate carbon, water and potentially nitrogen fluxes from different canopy cover types.
  • Distributed hydrologic models – The original RHESSys utilized a single approach, TOPMODEL, to model soil moisture redistribution and runoff production. We now include two approaches:
    • TOPMODEL (Beven and Kirkby, 1979) is a quasi distributed model. TOPMODEL distributes hillslope soil moisture based on a distribution of a topograhically defined wetness index.
    • An explicit routing model is adapted from DHSVM (Wigmosta et al., 1994) which models saturated subsurface throughflow and overland flow via explicit connectivity. An important modification from the grid-based routing in DHSVM is the ability to route w ater between arbitrarily shaped surface elements. This allows greater flexibility in defining surface patches and varying shape and density of surface tesselation.
Describe key physical parameters and equations ---
Describe length scale and resolution constraints --
Describe time scale and resolution constraints --
Describe any numerical limitations and issues --

Describe available calibration data sets
Upload calibration data sets if available:
Describe available test data sets See uploaded data file (Data.tar); or visit:
Upload test data sets if available: Media:Data.tar
Describe ideal data for testing

Do you have current or future plans for collaborating with other researchers? --
Is there a manual available? Yes
Upload manual if available: Media:Tutorials RHESSys.tar
Model website if any
Model forum / discussion board RHESSys source code and various user support programs are freely available for download. Limited documentation is also available on the website. We do not have the resources, however, to freely provide technical support for new users. Workshops are periodically available. If you would like additional training, technical support or information on hosting a RHESSys workshop, etc., we may be able to provide this on a contractual basis - Please contact Christina Tague ( or Janet Choate ( for more information.
Comments To run RHESSys successfully, the user will need to invest quite a bit of time gathering both spatial and observed data, which may require additional work to format the data correctly. A sample dataset can be downloaded with tutorials to familiarize users with the data and formats required in order to run RHESSys.

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
christina Tague
Nr. of publications: 138
Total citations: 6561
h-index: 40
m-quotient: 1.21

Link to this page




Nr. of publications: 138
Total citations: 6561
h-index: 40
m-quotient: 1.21

Featured publication(s)YearModel describedType of ReferenceCitations
Tague, C. L.; Band, L. E.; 2004. RHESSys: Regional Hydro-Ecologic Simulation System—An Object-Oriented Approach to Spatially Distributed Modeling of Carbon, Water, and Nutrient Cycling. Earth Interactions, 8, 1–42. 10.1175/1087-3562(2004)82.0.CO;2
(View/edit entry)
2004 RHESSys
Model overview 407
See more publications of RHESSys



Input Files

Output Files