# Pit Remove

(c) 2010 by David G. Tarboton
Identifies all pits in the DEM and raises their elevation to the level of the lowest pour point around their edge. Pits are low elevation areas in digital elevation models (DEMs) that are completely surrounded by higher terrain. They are generally taken to be artifacts that interfere with the routing of flow across DEMs, so are removed by raising their elevation to the point where they drain off the edge of the domain. The pour point is the lowest point on the boundary of the "watershed" draining to the pit. This step is not essential if you have reason to believe that the pits in your DEM are real. If a few pits actually exist and so should not be removed, while at the same time others are believed to be artifacts that need to be removed, the actual pits should have "no data" elevation values inserted at their lowest point. "No data" values serve to define edges in the domain, and elevations are only raised to where flow is off an edge, so an internal "no data" value will stop a pit from being removed, if necessary.

## Parameters

Number of Processes
Integer
  The number of stripes that the domain will be divided into and the number of MPI parallel processes that will be spawned to evaluate each of the stripes.
Elevation Grid
Raster Grid
  A digital elevation model (DEM) grid to serve as the base input for the terrain analysis and stream delineation.

## Outputs

Pit Removed Elevation Grid
Raster Grid
  A grid of elevation values with pits removed so that flow is routed off of the domain.