Curvature
Definition
A DTM derivative measuring the rate of change of slope. Profile curvature (along the slope direction) identifies convex mounds and concave hollows. Plan curvature identifies areas of convergent or divergent flow. Together they are sensitive indicators of micro-topographic anomalies.
- Data source
- Digital Terrain Model (DTM)
- Profile curvature
- Measures rate of change along slope direction
- Plan curvature
- Measures convergent or divergent flow
- Use case
- Detecting micro-topographic anomalies
Common questions
How is curvature different from a hillshade or slope map?+
Slope shows steepness and hillshade shows illumination, both of which can hide subtle features under certain light angles, while curvature is a second derivative that highlights concave and convex breaks in the surface regardless of sun position.
Why does curvature help find a clandestine grave that a bare-eye site walk misses?+
A backfilled grave often leaves a very shallow convex mound or a slight concave settling depression that is too subtle to see on the ground but stands out as a distinct curvature signature once the terrain is modeled numerically.
Related terms
- Bare-Earth DTM
- A digital terrain model produced by filtering LiDAR returns to ground-level pulses only, removing vegetation and structure returns. The resulting surface represents...
- Hillshade
- A raster derived from a DTM by simulating illumination from a defined sun position (azimuth and altitude angle). Produces light-and-shadow contrasts that...
- LiDAR (Light Detection and Ranging)
- An active remote sensing technique that emits laser pulses and measures the time of return to calculate distance to reflecting surfaces. Airborne...
- Point Density
- The number of LiDAR returns per unit area of ground surface, typically expressed as points per square metre. Higher density enables finer...
- Terrestrial Laser Scanning (TLS)
- A ground-based 3D LIDAR survey instrument that captures millions of range measurements per scan to produce a millimetre-accurate point cloud of the...