Model:Hilltop flow routing


Hilltop flow routing


Also known as Hillslope length measurement tool
Model type Tool
Model part of larger framework
Note on status model
Date note status model
Incorporated models or components:
Spatial dimensions 2D
Spatial extent Landscape-Scale
Model domain Terrestrial
One-line model description Algorithm for directly measuring hillslope length from high resolution topographic data
Extended model description This tool produces a flow path for each hilltop pixel on a landscape, generating hillslope length and relief data at a hillslope scale. These data can be used to discriminate between linear and nonlinear sediment flux laws at a landscape scale.

The model requires an input DEM in float format and produces a series raster and plain text output files which can be visualized and analysed using code provided at:

For detailed information about how to use this tool please refer to the documentation (


geomorphology, Hillslope Model, Sediment flux, flow path,

Name Stuart Grieve
Type of contact Model developer
Institute / Organization University of Edinburgh
Postal address 1 Geography Building
Postal address 2 Drummond Street
Town / City Edinburgh
Postal code EH8 9XP
Country United Kingdom
Email address
Phone +44 (0)131 650 9170

Name Simon Mudd
Type of contact Model developer
Institute / Organization University of Edinburgh
Postal address 1 Geography Building
Postal address 2 Drummond Street
Town / City Edinburgh
Postal code EH8 9XP
Country United Kingdom
Email address
Phone +44 (0)131 651 9090

Name Martin Hurst
Type of contact Model developer
Institute / Organization British Geological Survey
Postal address 1 Keyworth
Postal address 2
Town / City
Postal code
Country United Kingdom
Email address

Supported platforms
Unix, Linux
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 2013
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 CSDMS repository
Source web address
Source csdms web address
Program license type GPL v2
Program license type other
Memory requirements Varies depending on the input DEM size
Typical run time 3 hours to 3 days

Describe input parameters The input files are a DEM in .flt format, a channel heads file generated using the DrEICH algorithm ( and an optional floodplain mask in .flt format. Input parameters are also supplied at the command line. Information on the parameters is available in the documentation (
Input format Binary
Other input format
Describe output parameters The output data is both plain text data files and .flt raster files containing the spatial location of the computed results.
Output format ASCII, Binary
Other output format
Pre-processing software needed? Yes
Describe pre-processing software A channel network must be extracted for the landscape, this is performed using the DrEICH algorithm (
Post-processing software needed? No
Describe post-processing software
Visualization software needed? Yes
If above answer is yes ESRI
Other visualization software All output files can be visualized using the python tools provided at and .flt files can be loaded into many GIS packages (ArcGIS, Whitebox, QGIS).

Describe processes represented by the model The module generates hillslope profiles by routing flow from every point on a drainage divide into a channel.
Describe key physical parameters and equations [[Describe key physical parameters::The user must select a drainage basin strahler order to use as the basis for generating drainage divides. The larger the value, the fewer profiles will be generated. A value of 2 is recommended in order to generate a large density of data, while ensuring that only true drainage divides are sampled.

The window size for the surface fitting routine must be defined. The selection of this parameter is performed using an algorithm included in this package which implements a technique for window size selection described by Roering et al. (2010) [1] and Hurst et al. (2012) [2]]]

Describe length scale and resolution constraints This algorithm attempts to measure individual hillslopes, which are can be resolved at a range of spatial scales. It is recommended to use high resolution topographic data (<4 meter resolution) to ensure that a broad range of hillslopes can be sampled.
Describe time scale and resolution constraints No time resolution constraints as this software performs topographic analysis.
Describe any numerical limitations and issues As the size of the DEM increases, processing time will increase. An 8000*8000 DEM will take several days to process. Documentation is available to help users select appropriate input parameters.

Describe available calibration data sets Topographic analysis; no calibration required.
Upload calibration data sets if available:
Describe available test data sets Input data used in the preparation of the associated manuscript is all available from along with all processing and visualization code at so users can compare their results with those contained within the manuscript.
Upload test data sets if available:
Describe ideal data for testing Any 1m resolution digital elevation model.

Do you have current or future plans for collaborating with other researchers? Yes
Is there a manual available? No
Upload manual if available:
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
Is this a data component
Can be coupled with:
Model info
Stuart Grieve
Mudd, Hurst
Nr. of publications: 1
Total citations: 51
h-index: 1
m-quotient: 0.12

Link to this page




Nr. of publications: 1
Total citations: 51
h-index: 1
m-quotient: 0.12

Featured publication(s)YearModel describedType of ReferenceCitations
Grieve, Stuart W.D.; Mudd, Simon M.; Hurst, Martin D.; 2016. How long is a hillslope?: How long is a hillslope?. Earth Surface Processes and Landforms, 41, 1039–1054. 10.1002/esp.3884
(View/edit entry)
2016 Hilltop flow routing
Model overview 51
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Input Files

Output Files