Also known as
Model type Single
Model part of larger framework
Incorporated models or components:
Spatial dimensions 1D, 2D
Spatial extent Continental, Global, Landscape-Scale, Patch-Scale, Reach-Scale, Regional-Scale, Watershed-Scale
Model domain Coastal, Marine
One-line model description Numerical model to compute tsunami propagation and runup on land in the shallow-water approximation
Extended model description Cliffs features:

Shallow-Water approximation; Use of Cartesian or spherical (lon/lat) coordinates; 1D and 2D configurations; Structured co-located grid with (optionally) varying spacing; Run-up on land; Initial conditions or boundary forcing; Grid nesting with one-way coupling; Parallelized with OpenMP; NetCDF format of input/output data.

Cliffs utilizes VTCS-2 finite-difference scheme and dimensional splitting as in (Titov and Synolakis, 1998), and reflection and inundation computations as in (Tolkova, 2014).

References: Titov, V.V., and C.E. Synolakis. Numerical modeling of tidal wave runup. J. Waterw. Port Coast. Ocean Eng., 124(4), 157–171 (1998) Tolkova E. Land-Water Boundary Treatment for a Tsunami Model With Dimensional Splitting. Pure and Applied Geophysics, 171(9), 2289-2314 (2014)


Tsunami, Inundation, Runup on land, Shallow-water model,

First name Elena
Last name Tolkova
Type of contact Model developer
Institute / Organization NorthWest Research Associates, Inc.
Postal address 1 4118 148th Ave NE
Postal address 2
Town / City Redmond
Postal code 98052
State Washington
Country United States
Email address
Phone 4258895991
Fax 4255569099

Supported platforms Unix, Linux, Mac OS
Other platform
Programming language Fortran90
Other program language
Code optimized Multiple Processors
Multiple processors implemented Shared memory
Nr of distributed processors
Nr of shared processors
Start year development 2013
Does model development still take place? Yes
If above answer is no, provide end year model development
Code development status Only maintenance
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 BSD or MIT X11
Program license type other
Memory requirements 100 MB - few GB in 2D, depending on grid size
Typical run time 1 sec - few hrs, depending on 1D or 2D, grid size, and length of simulation

Describe input parameters integer - type of coordinates (1 - cartesian, otherwise-spherical)

DEM file name number of grids enclosed in Master grid enclosed DEMs file names if any still sea threshold minimal flow depth friction coefficient topo flag: 0-wall, otherwise - land inundation depth to place vertical wall, if any time step total amount of steps integer - apply initial deformation to bottom or sea surface integer - flag to continue or stop after input stops (0 for interrupt) number of steps between screenshots number to subsample screenshots in x number to subsample screenshots in y number of timesteps between saving boundary feed to enclosed grids number of steps between maxwave updates number of virtual gages steps between outputs in gage time histories i,j indexes of gage locations on the grid

Input format ASCII, Binary
Other input format Input data in NetCDF format:

bathymetric grids, and any of the following: boundary input time histories, and/or initial displacement of sea floor or sea surface, and/or either or both components of the initial velocity of the water column.

Describe output parameters Netcdf binaries of velocities and elevation screenshots in Master grid

�Netcdf binary of maximum water surface elevation in Master grid �Netcdf Time histories of the water surface elevation at virtual gages; Netcdf binaries of boundary input time-series for the enclosed grids, one �file for each boundary (east, west, north, south)

Output format Binary
Other output format Text log file documenting the program execution.
Pre-processing software needed? Yes
Describe pre-processing software To improve stability of the computations, it is recommended to pre-process bathymetry map with depth_ssl (module included with the source code).
Post-processing software needed? No
Describe post-processing software
Visualization software needed? Yes
If above answer is yes
Other visualization software Whatever a user prefers to visualize netcdf data sets

Describe processes represented by the model Tsunami propagation from a source earthquake to a coastal site, land inundation.
Describe key physical parameters and equations Shallow-water equations
Describe length scale and resolution constraints Typical resolution for open-ocean propagation: 2-4 arc-min, near the coast: 30-1 arc-sec; for lab experiments: tens to few cm.
Describe time scale and resolution constraints Time step is limited by Courant stability criteria (CFL < 1). Typical time step for open-ocean propagation: 15 s; near the coast: 0.5-5 s. Typical simulation time for geophysical tsunamis: few to 36 hours.
Describe any numerical limitations and issues Subject to CFL stability condition. Sharp depth changes can cause instability even with low Courant numbers. Pre-processing with depth_ssl is recommended (see Cliffs User Manual at )

Describe available calibration data sets Cliffs is benchmarked as described in: E. Tolkova. Land-Water Boundary Treatment for a Tsunami Model With Dimensional Splitting

Pure and Applied Geophysics, Vol. 171, Issue 9 (2014), pp. 2289-2314

Examples of modeling with Cliffs (complete set-ups included) are described in Cliffs User Manual at

Upload calibration data sets if available:
Describe available test data sets

for description of the test data sets, see

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

Do you have current or future plans for collaborating with other researchers? no plans yet
Is there a manual available? Yes
Upload manual if available: Media:Cliffs manual.pdf
Model website if any
Model forum / discussion board

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
Can be coupled with:
Model info
Citation indices Cliffs
Nr. of pubs: 3
Citations: 57
h-index: 3
Qrcode Cliffs.png
Link to this page




Citation indices Cliffs
Nr. of pubs: 3
Citations: 57
h-index: 3

Featured publication(s)YearModel describedType of ReferenceCitations
Tolkova, Elena; 2014. Land–Water Boundary Treatment for a Tsunami Model With Dimensional Splitting. Pure and Applied Geophysics, 171, 2289–2314. 10.1007/s00024-014-0825-8
(View/edit entry)
Model overview 11
See more publications of Cliffs



Input Files

Output Files