Landform Maps of Wisconsin: Ridges, Hollows and Valleys
Where are the ridges, the draws and the flats on this property? Label every part of the ground by its shape, at the scale you choose, from USGS 3DEP lidar.
Map a property now
Select the parcel, set the search radius and run Landforms. Each landform gets its own color.
Open Landforms →Reading the shape of the land
Contour lines hold all the information about the shape of the ground, but reading them takes practice, and under a woodlot the shape is hard to see on the ground too. A landform map does the reading for you. Every cell is labeled as one of ten landforms, so the ridges, spurs, hollows and valleys show up as patches of color.
Wisconsin has a great deal to read. The Driftless Area is ridges and coulees cut by streams; the Kettle Moraine is knobs, ridges and closed kettles left by the ice; the bluffs around Devils Lake and along the Mississippi are spurs and hollows on steep ground. The Landforms tool labels each of them the same way.
The ten landforms
| Landform | What it is on the ground |
|---|---|
| Peak | Ground falls away in every direction: a summit or knoll. |
| Ridge | A high crest, falling away on both sides. Exposed to wind and sun. |
| Shoulder | The convex edge where a flat top breaks into a slope. |
| Spur | A nose of ground running out from a hill. Well drained and exposed. |
| Slope | Even hillside, neither concave nor convex. |
| Hollow | A concave draw in a hillside. Water and cold air gather here. |
| Footslope | The concave base of a slope, where it eases out onto flatter ground. |
| Valley | Low ground between higher ground on both sides. Where the water runs. |
| Pit | Ground rises in every direction: a closed depression, such as a kettle. |
| Flat | No clear rise or fall at the radius chosen. |
What people use it for
- Siting buildings. Ridges and shoulders are exposed; hollows collect water and cold air. A house site on a spur or a gentle shoulder is often a good compromise, and the map shows where they are.
- Planting and livestock. Frost-tender crops away from the hollows where cold air pools; shelter for stock in the lee of a ridge.
- Forestry and trails. Follow the spurs for a dry trail or a skid road; cross the hollows where you must.
- Drainage. Valleys, hollows and pits are where water goes. Pits in glacial country are often kettles that hold water.
- Ecology and teaching. A geomorphon map without installing GIS, for fieldwork, classes and habitat mapping.
How to make a landform map
- Select the area. Click the parcel, draw a box or polygon, or upload a boundary. Without a selection, Analyze this view uses the area on screen.
- Set the search radius, in feet, up to 820 ft. Small radii pick out field-scale features; large radii describe the hill as a whole.
- Choose Run analysis. Each landform has its own color, and the panel gives each one's share of the area.
- Zoom in to follow the spurs and the hollows between them, and switch to the aerial basemap to see what grows on each.
- Run it again at another radius. Results use the settings from the last run, so change the radius and run again to compare.
Scale is the whole point
Landform depends on how far you look. Stand on a bench halfway up a Driftless hillside and it is flat; step back across the valley and it is part of a slope. A small radius answers questions about where a road or a building pad sits; a large radius answers questions about which side of the hill you are on. Neither is wrong. If the map looks noisy, increase the radius; if it misses a draw you know is there, reduce it.
Put numbers on the shape
Landforms names the shape. These measure it.
Limits
Areas are sampled more coarsely than contours, so on a large area the smallest features can be missed; select a smaller area for detail. The classes come from the shape of the bare ground only, not from soil, rock or vegetation. For what lies under the surface, the Wisconsin Geological and Natural History Survey publishes geologic information for the state.
About the data
Ground elevations come from the USGS 3D Elevation Program (3DEP) seamless bare-earth model, with elevations above NAVD 88. Source cells are 3.3 ft per pixel in the finest work units, with about 9.8 ft per pixel and 33 ft per pixel sources elsewhere. USGS elevation data is public domain. Lidar coverage and source dates vary across Wisconsin. Check your site against the USGS 3DEP work-unit index; an unavailable lookup means coverage is unknown. On ground covered only by coarser sources, small features blur and more of the map reads as slope or flat. More from the USGS 3D Elevation Program and Wisconsin elevation resources.
Frequently asked questions
What is a landform classification map?
A map that labels each part of the ground by its shape: peak, ridge, shoulder, spur, slope, hollow, footslope, valley, pit or flat. It turns a contour map, which takes practice to read, into named features you can see at a glance.
What method does it use?
Geomorphons. From each cell the tool looks out in eight directions to the radius you set and records whether the ground rises or falls in each. The pattern of rises and falls is matched to one of ten landform types.
What search radius should I use?
Small radii, a few dozen feet, pick out field-scale features such as banks, ditches and small knolls. Large radii, up to 820 ft, describe the hill as a whole. Run the same area at two radii; the classes change, because landform depends on the scale you look at.
Why does the same hillside read as slope at one radius and spur at another?
Because both are true. Close up, a rounded nose of ground on a hillside is a slope; seen from farther out, it stands out from the hollows either side as a spur. The radius decides which question you are asking.
Can I download the landform map?
Yes, as a GeoTIFF for GIS, from the results panel. Downloading needs a pass; the map itself is free to run.
Related guides
- Topographic maps of Wisconsin — make and read topo maps from lidar.
- Contour lines for Wisconsin — the shape of the ground as lines.
- Find wet ground with the topographic wetness index — where the hollows and valleys keep ground wet.