TopoToolbox - a set of Matlab functions for topographic analysis

TopoToolbox provides a set of Matlab functions that support the analysisof relief and flow pathways in digital elevation models. The majoraim of TopoToolbox is to offer helpful analytical GIS utilities in anon-GIS environment in order to support the simultaneous applicationof GIS-specific and other quantitative methods.

If you have any questions or remarks, please contact the authors:

Wolfgang Schwanghartw.schwanghart[at]geo.uni-potsdam.de

Dirk Scherlerscherler[at]gfz-potsdam.de

Requirements

TopoToolbox is plat-form independent and requiresMatlab 2016b or higher and the Image Processing Toolbox. The MappingToolbox is not mandatory, but good to have to facilitate easy dataexchange with GIS software. Some functions support parallelisation using theParallel Toolbox. Few functions require the Optimization or Statisticsand Machine Learning Toolbox.

References

When you use TopoToolbox in your work, please reference followingpublication:

• Schwanghart, W., Scherler, D. (2014): TopoToolbox 2 – MATLAB-basedsoftware for topographic analysis and modeling in Earth surface sciences.Earth Surface Dynamics, 2, 1-7. DOI: 10.5194/esurf-2-1-2014

If you are using version 1, then please refer to this publication:

• Schwanghart, W., Kuhn, N.J. (2010): TopoToolbox: a set of MATLABfunctions for topographic analysis. Environmental Modelling & Software,25, 770-781. DOI: 10.1016/j.envsoft.2009.12.002

In addition, various models and algorithms used in TopoToolbox have been published in the following articles.

DEM preprocessing and carving

• Schwanghart, W., Groom, G.B., Kuhn, N.J., Heckrath, G., 2013: Flow network derivation from a highresolution DEM in a low relief, agrarian landscape. Earth Surface Processes and Landforms, 38,1576-1586. DOI: 10.1002/esp.3452

• Schwanghart, W., Scherler, D., 2017. Bumps in river profiles: uncertainty assessment and smoothingusing quantile regression techniques. Earth Surface Dynamics, 5, 821-839. DOI: 10.5194/esurf-5-821-2017

TopoToolbox Landscape Evolution Modelling (TTLEM) and HyLands

• Campforts, B., Schwanghart, W., Govers, G. (2017): Accurate simulation of transientlandscape evolution by eliminating numerical diffusion: the TTLEM 1.0 model.Earth Surface Dynamics, 5, 47-66. DOI: 10.5194/esurf-5-47-2017

• HyLands: Campforts B., Shobe M.C., et al. (2020): HyLands 1.0: a Hybrid Landscapeevolution model to simulate the impact of landslides and landslide-derived sediment on landscape evolution.Geosci. Model Dev., 13, 3863–3886. DOI: 10.5194/gmd-13-3863-2020

Excess topography

• Blöthe, J.H., Korup, O., Schwanghart, W., 2015: Large landslides lie low: Excess topography in the Himalaya-Karakorum ranges.Geology, 43, 523-526. DOI: 10.1130/G36527.1

Knickpointfinder

• Stolle, A., Schwanghart, W., Andermann, C., Bernhardt, A., Fort, M., Jansen, J.D., Wittmann, H., Merchel, S.,Rugel, G., Adhikari, B.R., Korup, O., 2019. Protracted river response to medieval earthquakes. Earth Surface Processesand Landforms, 44, 331-341. DOI: 10.1002/esp.4517 (The description here is very terse, yet)

Divide functions

• Scherler, D., Schwanghart, W., 2020. Drainage divide networks – Part 1: Identification and ordering in digital elevation models.Earth Surface Dynamics, 8, 245–259. DOI: 10.5194/esurf-8-245-2020

• Scherler, D., Schwanghart, W., 2020. Drainage divide networks – Part 2: Response to perturbations.Earth Surface Dynamics, 8, 261-274. DOI: 10.5194/esurf-8-261-2020

Point patterns on stream networks

• Schwanghart, W., Molkenthin, C., & Scherler, D. (2020). A systematic approach and software for the analysisof point patterns on river networks. Earth Surface Processes and Landforms, accepted. DOI: 10.1002/esp.5127

Getting started

Before working with TopoToolbox the directories and functions must be on the searchpath of Matlab. Enter following code into the command line:

    addpath(genpath('C:\path\to\wherever\you\installed\this\TopoToolbox-2'))

To remove .git-folders from the path, run

    rmpath(genpath('C:\path\to\wherever\you\installed\this\TopoToolbox-2\.git'));

Type doc in the command line to open the main documentation page. You'llfind the TopoToolbox documentation in the section Supplemental Software.
The documentation contains several user's guides that will help yougetting started. In addition, TopoToolbox functions have extensive helpsections (e.g. help gradient8 or help STREAMobj/modify. An additionalresource for code and examples is the TopoToolbox blog.

Version History

pre 2.4

• HyLands 1.0 added: see paper: Campforts, B. et al. (2020): HyLands 1.0: a Hybrid Landscape evolutionmodel to simulate the impact of landslides and landslide-derived sediment on landscape evolution
  Geoscientific Model Development. DOI:10.5194/gmd-13-3863-2020
• new class: DIVIDEobj Paper 1 DOI: 10.5194/esurf-8-245-2020Paper 2 DOI: 10.5194/esurf-8-261-2020
• new class: PPS DOI: 10.1002/esp.5127
• modification: update to ttscm to Scientific Colormaps 7.0see Fabio Crameri's website
• new function: GRIDobj/diffusion
• new function: GRIDobj/histogram
• new function: STREAMobj/extend2divide
• new function: STREAMobj/binarize
• modification: STREAMobj/modify
• modification: STREAMobj/wmplot
• new function: STREAMobj/STREAMobj2shape
• new function: STREAMobj/isequal
• new function: STREAMobj/STREAMobj2kml
• new function: STREAMobj/getlocation
• modification: STREAMobj/smooth
• new function: STREAMobj/mnoptimvar
• modification: STREAMobj/STREAMobj2cell
• modification: GRIDobj/demprofile
• new function: ScaleBar
• new function: xlinerel and ylinerel
• topoapp was removed from this version
• updates to readopentopo
• updates to utilities: setextent and getextent
• new function: padextent

2.3

• Documentation in the documentation browser
• new function: ttcmap for creating nice colormaps for DEMs, particularlyif DEMs include topography and bathymetry
• FLOWobj2gradient renamed to gradient
• new function: ttscm for access to scientific colormaps;see Fabio Crameri's website
• new function: mappingapp (lightweighed GUI for mapping points simultaneously inplanform and profile view) still beta!
• new function: FLOWobj/mapfromnal
• enhancement: FLOWobj/multi2single allows area thresholding
• new function: STREAMobj/getvalue
• new function: STREAMobj/hillslopearea
• new function: STREAMobj/zerobaselevel
• new function: STREAMobj/knickpointfinder
• new function: STREAMobj/stackedplotdz
• new function: STREAMobj/sinuosity
• new function: STREAMobj/clean
• new function: STREAMobj/nal2nal
• new function: STREAMobj/netdist
• new function: STREAMobj/tribdir
• new function: GRIDobj/clip
• new function: GRIDobj/GRIDobj2im
• new function: GRIDobj/getextent
• new function: IOtools/readexample
• renamed GRIDobj/project2GRIDobj to GRIDobj/project. In addition, the function hasa number of new functionalities.
• modification: STREAMobj/modify has new options for interactively modifying stream networksand to extract streams that confluence from a specified direction.
• changes to readopentopo, getcoordinates, getoutline, polygon2GRIDobj, line2GRIDobj
• new function: hydrosheds2FLOWobj (see in IOtools)
• new function: egm96heights including the grid ww15mgh.grd that contains global geoidundulations based on the EGM96 geoid.

2.2

• TTLEM is part of TopoToolbox;see our paper: Campforts, B., Schwanghart, W., Govers, G. (2017): Accurate simulationof transient landscape evolution by eliminating numerical diffusion: the TTLEM 1.0 model.Earth Surface Dynamics, 5, 47-66. DOI: 10.5194/esurf-5-47-2017
• new functions for smoothing and hydrological correction:STREAMobj/crs, STREAMobj/crsapp, STREAMobj/smooth, STREAMobj/crslin,STREAMobj/quantcarve, FLOWobj/quantcarve;see our paper: Schwanghart, W., Scherler, D., 2017. Bumps in river profiles: uncertaintyassessment and smoothing using quantile regression techniques. Earth Surface Dynamics, 5,821-839. DOI: 10.5194/esurf-5-821-2017
• modification: GRIDobj way to store referencing information was changed
• modification: FLOWobj now supports multiple flow directions and Dinf.
• modification: several new options for imageschs
• new function: FLOWobj/dbentropy
• new function: FLOWobj/updatetoposort
• new function: GRIDobj/aggregate
• new function: GRIDobj/createmask
• new function: GRIDobj/dist2line
• new function: GRIDobj/dist2curve
• new function: GRIDobj/line2GRIDobj
• new function: GRIDobj/GRIDobj2pm
• new function: GRIDobj/minmaxnorm
• new function: GRIDobj/reclabel
• new function: GRIDobj/zscore
• new function: GRIDobj/pad
• new function: STREAMobj/aggregate
• new function: STREAMobj/labelreach
• new function: STREAMobj/distance
• new function: STREAMobj/drainagedensity
• new function: STREAMobj/plotc
• new function: STREAMobj/plotdzshaded
• new function: STREAMobj/meanupstream
• new function: STREAMobj/plot3
• new function: STREAMobj/chitransform
• new function: STREAMobj/cumtrapz
• modification: STREAMobj/modify includes option rmconncomps
• new function: STREAMobj/mchi
• new function: STREAMobj/conncomps
• modification: STREAMobj/extractconncomps (new GUI and behavior)
• modification: STREAMobj/union (new syntax)
• modification: STREAMobj/intersect (new syntax)
• new function: STREAMobj/isnal
• new function: STREAMobj/info
• new function: STREAMobj/orientation
• new function: STREAMobj/plotstreamorder
• new function: STREAMobj/removeedgeeffects
• new function: STREAMobj/split
• new function: STREAMobj/streamproj
• new function: STREAMobj/networksegment
• new function: STREAMobj/maplateral
• new function: STREAMobj/plotsegmentgeometry
• new function: STREAMobj/randlocs
• new function: STREAMobj/zerobaselevel
• modification: STREAMobj/streamorder plotting option removed
• modification: STREAMobj/plotdz includes custom distance option
• modification: STREAMobj/distance includes option to derive distance from differentSTREAMobj
• modification: STREAMobj/STREAMobj2cell
• modification: STREAMobj/STREAMobj2mapstruct
• new function: STREAMobj/transformcoords
• new function: FLOWobj/FLOWobj2cell
• update to several FLOWobj methods to avoid speed loss for MATLAB versions newerthan R2015b
• removed bug in GRIDobj/curvature

2.1

• new function: GRIDobj/excesstopography; see our paper Blöthe, J.H., Korup, O.,Schwanghart, W. (2015): Large landslides lie low: Excess topography in theHimalaya-Karakorum ranges. Geology, 43, 523-526. DOI: 10.1130/G36527.1
• new function: GRIDobj/GRIDobj2polygon
• new function: STREAMobj/getnal
• new function: STREAMobj/sidebranching
• new function: STREAMobj/mincosthydrocon
• new function: STREAMobj/intersectlocs
• new function: STREAMobj/densify
• new function: STREAMobj/plot3d
• new function: STREAMobj/widenstream
• new function: demo_modifystreamnet
• modification of the function slopearea
• better performance of FLOWobj when converting from flow direction matrixby using dmperm to perform topological sort
• new function: GRIDobj/toposhielding
• new function: demarea (incorporation of Juernjakob Dugge's function:http://www.mathworks.com/matlabcentral/fileexchange/42204-calculate-dem-surface-area )
• new function: GRIDobj/getoutline
• removed a bug when some functions such log, log10 were called with integerGRIDobjs
• additional overloading of built-in functions for GRIDobjs. We added matrixarithmetics, which, however, perform element-wise operations (e.g. mtimes canbe used with GRIDobj now, but performs times)
• the scope of the function GRIDobj/localtopography was enhanced (min, max,percentiles, etc in a disk-shaped neighborhood)
• FLOWobj/streampoi and STREAMobj/streampoi now return 'bconfluences',e.g. stream pixels that in downstream direction are located immediatelybefore confluences.
• new function: STREAMobj/imposemin - limits downstream minima impositionto the stream network
• several bug fixes
• demo_modifystreamnet.m
• preprocessapp was removed

V2.0.1

• removed bug in GRIDobj
• removed bug with case-sensitivity in some functions
• removed bug with internal drainage option in FLOWobj

V2.0

• new functions STREAMobj/intersect, STREAMobj/union
• new interactive tools in STREAMobj/modify
• new interactive tool GRIDobj/measure

V2.0beta

V2.0 introduces an object oriented approach towards grid representation, flow direction, streamnetworks and swath objects. The performance of various, inparticular flow related, functions wasincreased. Mex-files have been written to increase the speed of some functions and are delivered as64bit Windows binaries. They have been compiled on Windows 7 with an Intel processor, so they should becompiled before using them, if your system differs. However, compiling is not mandatory, since mversions are available, too, which are a little slower. Please refer to the Contents.m file for acomplete list of functions.

V1.06 --- 11. November 2011

• new function: acv
• new function: cropmat
• new function: dbentropy
• new function: deminpaint
• new function: exaggerate
• new function: label2poly
• new function: routegeodesic (as optimal method for routing through flats andpits). Requires Matlab 2011b and will be made the default routing algorithmin future releases.
• new function: upslopesidelength
• new function: upslopestats
• new function: getextent and setextent
• function enhancements: rasterread and rasterwrite.
• function enhancements: roughness
• new users guide on processing flat areas
• the baranja_hill.mat dataset was added. It was obtained fromhere: http://geomorphometry.org/content/baranja-hill

V1.05 --- 15. September 2010

• some of the functions now employ the function validateattributes to checkinput arguments. Note that this might return a warning on older versions than2009a.
• a bug in routeflats was removed
• new function: M2UV
• new function: twi
• new function: aspect
• new function: ismulti
• new function: postprocflats
• new function: demsobel
• new function: hypscurve
• new function: roughness
• removed bug in flowacc. flowacc returned an error when called with threeinput arguments
• gradient8 allows you to output different angular units, major speedincrease when called with gradient as sole output argument.
• functional enhancements to flowdistance (see help flowdistance)
• functional enhancements to identifyflats
• rasterread and rasterwrite now feature dialog boxes for reading andsaving files if no filenames are supplied to the function
• flowdistanceds can now calculate the maximum downward flowpath distancefor each cell at one step.

V1.04 --- 5. January 2010 - first public release

• a bug in flowacc_lm was removed. When a weight matrix W0was supplied as additional input argument, W0 was set todem.
• new function: imageschs
• minor changes to hillshade were made. The algorithm is nowbased on method proposed by Katzil and Doytsher, 2003.
• flowacc allows for another input argument (runoff ratio).

V1.03 --- 5. November 2009

• sub-basin analysis has been added as new functionality(see sbstruct, sbplot, sbprops)
• new function: adjustgauges

V1.02 --- 30. October 2009

• major speed enhancement for fillsinks with maximumfill depth

V1.01 --- 16. September 2009

• hillshade plots the hillshade matrix when no outputarguments are defined.
• flowacc_lm was optimized, so that large, flat areasare handled more memory efficiently.
• a bug in routeflats was removed.
• crossflats was updated to run most efficient onMatlab R2009a.
• drainagebasins functionality was enhanced to allowfor the delineation of drainage basins of specifiedorder. The former support of multiple flow directionhas been removed.
• new function: drainagedensity
• new function: shufflelabel
• influencemap got a second output Mstreams

V1.0 --- 15. March 2009

• release