EGU2020-19260
https://doi.org/10.5194/egusphere-egu2020-19260
EGU General Assembly 2020
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.

The TopoToolbox v2.4: new tools for topographic analysis and modelling

Dirk Scherler1,2 and Wolfgang Schwanghart3
Dirk Scherler and Wolfgang Schwanghart
  • 1GFZ Potsdam, Section 3.3: Earth Surface Geochemistry, Potsdam, Germany (scherler@gfz-potsdam.de)
  • 2Institute of Geological Sciences, Freie Universität Berlin, Berlin, Germany
  • 3Institute of Environmental Sciences and Geography, University of Potsdam, Potsdam, Germany

The TopoToolbox v2 (TT2; available at https://github.com/wschwanghart/topotoolbox) (Schwanghart and Scherler, 2014) is a set of functions for the analysis of digital elevation models (DEM) in the MATLAB programming environment. Its functionality is mainly developed along the lines of hydrological and geomorphic terrain analysis, complemented with a wide range of functions for visual display, including a class for swath profiles. Fast and efficient algorithms in TopoToolbox form the backbone of the numerical landscape evolution model TTLEM (Campforts et al., 2017). In this presentation, we will demonstrate new functionalities that are part of the upcoming release v 2.4: DIVIDEobj and PPS.

DIVIDEobj is a numerical class to store, analyze and visualize drainage divide networks. Drainage networks are derived from flow directions and a stream network. We will present the extraction and analysis of the drainage divide network of the Big Tujunga catchment, CA, to illustrate it functionality and associated analysis tools. PPS is a class to explore, analyze and model spatial point processes on or alongside river networks. Specifically, PPS provides access to a set of statistical tools to work with inhomogeneous Poisson point processes that facilitate the statistical modelling of phenomena such as river bank failures, landslide dams, or wood jams at the regional scale.

Campforts, B., Schwanghart, W., and Govers, G.: Accurate simulation of transient landscape evolution by eliminating numerical diffusion: the TTLEM 1.0 model, Earth Surface Dynamics, 5, 47-66. https://doi.org/10.5194/esurf-5-47-2017, 2017.

Schwanghart, W., and Scherler, D.: Short Communication: TopoToolbox 2 – MATLAB-based software for topographic analysis and modeling in Earth surface sciences, Earth Surf. Dynam., 2, 1-7, https://doi.org/10.5194/esurf-2-1-2014, 2014.

How to cite: Scherler, D. and Schwanghart, W.: The TopoToolbox v2.4: new tools for topographic analysis and modelling, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-19260, https://doi.org/10.5194/egusphere-egu2020-19260, 2020

Comments on the presentation

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Presentation version 1 – uploaded on 30 Apr 2020
  • CC1: Comment on EGU2020-19260, Jesse Zondervan, 07 May 2020

    I love the new DIVIDEobj! The inclusion of divide segment ordering is very useful for intracatchment studies. Is there an option to display drainage of certain order(s) only?

    Here's a question: what criteria do you use to assess the asymmetry of divides (in red in your figure). Is this based on Forte and Whipple's Matlab function DivideTools? 

    Your PPS class sounds interesting. Have you used this in any example of geomorphic analysis yet? 

    • AC1: Reply to CC1, Wolfgang Schwanghart, 07 May 2020

      Hi Jesse,

      thanks! I hope that we'll be able to put the DIVIDEobj on git soon. Dirk has tested it a lot, but please let us know if you face any issues with it.

      PPS is coming soon. Actually, the Roan Paper figure with the knickpoint chi distribution (Fig. 1d and 2b) were done with it. Currently, I am finishing writing a paper with other applications such as the distribution of beaver dams and wood jams.

      Cheers, Wolfgang

    • AC2: Reply to CC1, Dirk Scherler, 07 May 2020

      Hi Jesse,

      thanks for your feedback.

      Is there an option to display drainage of certain order(s) only? 

      With "drainage", do you mean streams or divides? For streams you can use the function modify to select certain strahler orders. For divides, most of the plotting functions allow to set the range of orders to display (min to max). But you will also be easily able to modify divides based on other criteria.

      Here's a question: what criteria do you use to assess the asymmetry of divides (in red in your figure). Is this based on Forte and Whipple's Matlab function DivideTools?

      No, the new DIVIDobj and related analysis has nothing to do with Forte and Whipple's divide tools. The divide asymmetry index is simply a numerical measure of how asymmetric the morphology of a divide is. More details on this index can be found in the ESurf papers.

      Thanks,

      Dirk

  • CC2: Comment on EGU2020-19260, Jesse Zondervan, 07 May 2020

    Hi Dirk,

    Thanks for answering my questions. Yes, I meant drainage divides. 

    Best,

    Jesse