Demetriades, A., 2025. Tutorial: Making Digital Topographical Maps. International Union of Geological Sciences, Commission on Global Geochemical Baselines, Tutorial Publication No. 1, 40 pp., 57 figures, Supplementary material; https://doi.org/10.5281/zenodo.14453284.
Making a topographical map in the digital age is a straightforward process. You only need a personal or laptop computer, internet access, and a Geographical Information System software. This tutorial utilises three fundamental software packages: (i) Google Earth Pro, (ii) GPS Visualizer, and (iii) Golden Software’s Surfer™. The longitude and latitude of digitised points along traverses are extracted from Google Earth Pro. Depending on the required details, a larger Google Earth image is digitised along traverses, which can be in any direction. The file with the longitude (x) and latitude (y) of point data is then copied online into GPS Visualizer, which uses data from different digital elevation models (DEM) to assign the optimum altitude or topographical height (z) in metres (or feet) of the digitised points along the traverses. The topographical data (x, y, z) exported from GPS Visualizer are plotted with Surfer™ or similar mapping software packages, and a digital topographical map of an area is made. This tutorial provides detailed instructions on plotting and annotating an area’s topographical map with modern digital tools.
SUMMARY
The publication provides a comprehensive tutorial on making digital topographical maps using modern technological tools. It was designed for a workshop held on August 30-31, 2024, during the 37th International Geological Congress in Busan, South Korea.
- Software Requirements: Google Earth Pro and GPS Visualizer are essential tools for the process, while Golden Software’s Surfer™ is used for plotting the topographical map. Golden Software offers a 14-day free trial and generous discounted licenses for students and educators.
- Step-by-Step Guide: The tutorial provides detailed, sequential instructions for each stage of making a digital topographical map, from marking the work area and digitising points in Google Earth Pro, to exporting digitised points to KML files, using GPS Visualizer to obtain altitude data for these points, and saving the point data to CSV format files.
- Cleaning files: Importing CSV files to Microsoft Excel®, cleaning the files by removing unnecessary columns and lines between the merged files, and preparing the final file for further use in Surfer™ or any other map-making software package.
- Plotting with Surfer™: The tutorial explains in detail how to use Surfer™ to plot the topographical map, a crucial step that includes setting up the grid data, selecting the appropriate gridding method, and adjusting the map’s coordinate system and scale.
- Additional Map Features: The document describes how to digitise additional map features such as streams, dams, irrigation ponds and roads in Google Earth, exporting them as KML files, and subsequently importing these features into Surfer™ for plotting a more detailed map composition.
Supplementary Material: The tutorial provides a list of supplementary files included in the tutorial package. These resources are designed to support you throughout the process, providing guidance and reference when you need it most.
Co-sponsors of Workshop: The International Union of Geological Sciences and the Association of Applied Geochemists co-sponsored the workshop.
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