Terrain map generator: shaded relief from a DEM in Python

What a terrain map generator does and why researchers need it

A terrain map generator converts raw elevation data — a digital elevation model, or DEM — into a readable picture of the landscape. Instead of a flat grid of numbers, you get shaded relief: simulated light and shadow that make ridges, valleys and coastlines stand out the way they would in an aerial photo. Layered on top is a hypsometric tint, where colour encodes height, so a reader can tell a floodplain from a plateau at a glance.

Researchers need this because topography is context. A hydrology paper has to show catchment relief; an ecology study needs elevation gradients behind its sampling sites; a geomorphology thesis treats the terrain itself as the subject. A clean relief map communicates all of that instantly. AcadGIS produces one from a place name or bounding box, so you spend your time on the science, not on wrangling raster tiles. It pairs naturally with a study area map generator when you need both location and landform on the same figure.

Make a terrain map in Python

The shortest path is to load a DEM for your area and call relief(). AcadGIS fetches Copernicus GLO-30 tiles behind the scenes, computes the hillshade, applies a terrain colour ramp and tints the ocean a distinct blue — no API key and nothing to install beyond the package.

Point load_dem() at any region name; it downloads the tiles it needs and caches them so the second run is instant. Set ocean_color to keep water from blending into low-lying land, and drop hillshade=False in if you want a flat colour-by-elevation map with no shadows.

import acadgis as agis
dem = agis.load_dem("Nepal")
ax = agis.relief(dem, cmap="terrain", hillshade=True, ocean_color="#a9c9df")
agis.save("nepal_terrain.png", dpi=300)

Layer relief under boundaries and rivers

Terrain rarely stands alone. Use add_topography() to drop shaded relief onto an existing axis, then layer administrative boundaries or a stream network on top. This is how you build the composite figure most papers actually want: landform as the backdrop, your features in front.

Because every AcadGIS layer shares the same academic theme and projection handling, relief sits cleanly beneath a river network map generator layer or your own sampling points, without alignment headaches.

import acadgis as agis
gdf = agis.load_boundaries("Nepal", level="district")
ax = agis.plot(gdf, theme="academic", title="Study region relief")
agis.add_topography(ax, area="Nepal", cmap="terrain", ocean_color="#a9c9df")
agis.add_rivers(ax, area="Nepal", by_order=True)

Realistic land-to-ocean colouring

The difference between an amateur relief map and a convincing one is usually the colour logic, and AcadGIS handles two things for you. First, hypsometric tinting maps elevation to a natural ramp — deep greens for lowlands, tans and browns for mid-elevations, grey and white for high peaks — so height is legible without reading the legend. Second, a separate ocean colour replaces the ambiguous near-zero elevations of the sea with a flat, honest blue, so coastlines stay crisp and readers never mistake water for a low plain.

You control both: pass any Matplotlib colormap to cmap (the built-in "terrain" ramp is a sensible default) and set ocean_color to match your figure palette. This is what lets a high-relief scene like the Alps hold together — deep shadow in the valleys, white on the summits — instead of turning into visual mush.

Data sources and tips

AcadGIS builds terrain from Copernicus GLO-30, ESA's global 30 m DEM — open, well-validated and consistent worldwide, which is why it needs no API key. Administrative boundaries come from GADM, rivers and coastlines from Natural Earth, and roads from OpenStreetMap, so a full figure draws on established, citable datasets.

A few tips for clean output:

• Cite your DEM. Credit Copernicus GLO-30 in your figure caption or methods — reviewers expect a named elevation source.
• Match extent to your data. Load the DEM for the same region as your boundaries so relief and features align without cropping.
• Export high-DPI raster or vector. Use agis.save("fig.png", dpi=300) for print-quality raster, or a PDF/SVG path for vector output.
• Keep it subtle. If relief competes with your data layer, soften it by turning off hillshade or choosing a muted ocean_color.

Building a full methods figure? See how terrain fits into a complete GIS map for a research paper.

Frequently asked questions