p align=”justify”>Digital elevation models (DEMs) exist today for the entire globe with consistent quality. Improvements in sensors and data processing give a clue that in the future elevation data will be available in even better spatial resolution and accuracy. Discovering the richness of information inherent in DEMs should thus be supported by good software.
Here, I want to give a brief account of TopoToolbox 2, the second version of a MATLAB toolbox for exploring and analyzing DEMs. Dirk Scherler from Caltech and I have been working on many changes to the previous version to make TopoToolbox faster, more memory efficient and easy-to-use. Specifically,
- we redesigned grid representation by adopting an Object-Oriented Programming (OOP) approach. Grids in ESRI ascii or tif format can now be directly loaded into MATLAB as instance of GRIDobj, which encapsulates all information on spatial referencing.
- we adopted a new strategy to store flow directions (FLOWobj). The approach uses a topological sorting of grid cell indices which increases the speed of all flow related calculations such as flow accumulation, flow distance etc. while being more memory efficient.
- we introduced a new object that stores information on river networks (STREAMobj)
- we included various new functions pertinent to river profile analysis (e.g. slope-area analysis, chiplots)
- we included GUIs that allow for interactive working with DEMs.
Finally, this project is always under construction and perhaps you have coded something that others desperately miss. Thus, if you want to contribute to our software, please send me your code.