This tool can be used to fill all of the depressions in a digital elevation model (DEM) and to remove the flat areas using the Planchon and Darboux (2002) method. This is a common pre-processing step required by many flow-path analysis tools to ensure continuous flow from each grid cell to an outlet located along the grid edge. This tool is currently not the most efficient depression-removal algorithm available in WhiteboxTools; fill_depressions and breach_depressions_least_cost are both more efficient and often produce better, lower-impact results.

The user may optionally specify the size of the elevation increment used to solve flats (`flat_increment`), although it is best not to specify this optional value and to let the algorithm determine the most suitable value itself.

## Reference

Planchon, O. and Darboux, F., 2002. A fast, simple and versatile algorithm to fill the depressions of digital elevation models. Catena, 46(2-3), pp.159-176.

## See Also

fill_depressions, breach_depressions_least_cost

## Function Signature

`def fill_depressions_planchon_and_darboux(self, dem: Raster, fix_flats: bool = True, flat_increment: float = float('nan')) -> Raster: ...`

## Project Links

WbW Homepage User Manual Support WbW