This tool calculates the total curvature, which measures the curvature of the topographic surface rather than the curvature of a line across the surface in some direction (Gallant and Wilson, 2000). Total curvature can be positive or negative, with zero curvature indicating that the surface is either flat or the convexity in one direction is balanced by the concavity in another direction, as would occur at a saddle point. Curvature is a second derivative of the topographic surface defined by a digital elevation model (DEM). The user must input a DEM (`dem`).The output reports curvature in degrees multiplied by 100 for easier interpretation, as curvature values are often very small. The Z Conversion Factor (`zfactor`) is only important when the vertical and horizontal units are not the same in the DEM. When this is the case, the algorithm will multiply each elevation in the DEM by the Z Conversion Factor. If the DEM is in the geographic coordinate system (latitude and longitude), with XY units measured in degrees, an appropriate Z Conversion Factor is calculated internally based on site latitude.

## Reference

Gallant, J. C., and J. P. Wilson, 2000, Primary topographic attributes, in Terrain Analysis: Principles and Applications, edited by J. P. Wilson and J. C. Gallant pp. 51-86, John Wiley, Hoboken, N.J.

plan_curvature, profile_curvature, tangential_curvature, slope, aspect

## Function Signature

`def total_curvature(self, dem: Raster, log_transform: bool = False, z_factor: float = 1.0) -> Raster: ...`

## Project Links

WbW Homepage User Manual Support WbW