Locates and fills sinks and peaks in an elevation surface raster to remove small imperfections in the data. The function will fill in an iterative process until all sinks are filled within the specified Z Limit.
This is a global raster function.
Notes
The Z Limit specifies the maximum difference allowed between the depth of a sink and the pour point and determines which sinks will be filled and which will remain untouched. The Z Limit is not the maximum depth to which a sink will be filled. All sinks that are less than the Z Limit, and lower than their lowest adjacent neighbor, will be filled to the height of their pour points. If the difference in z-values between a sink and its pour point is greater than the Z Limit, that sink will not be filled.
The Sink function can be used in advance of using the Fill function to find the number of sinks and help identify their depth. Knowing the depth of the sinks can help in determining an appropriate Z Limit.
The Fill function can also be used to remove peaks. A peak is a cell where no adjacent pixels are higher. To remove peaks, the input surface raster must be inverted. This can be performed with the Minus math function. Specify the highest value of the surface raster as the first input and surface raster as the second input in the Minus function.
The Z Limit can be applied to this process as well. If nothing is specified for z-limit, then all peaks will be removed. If it is specified, where the difference in z-value between a peak and its highest adjacent neighbor is greater than the Z Limit, that peak will not be removed.
If the surface raster is integer, the output filled raster will be integer type. If the input is floating point, the output raster will be floating point.
Parameters
| Parameter name | Description |
|---|---|
Raster | A single band raster elevation dataset. |
Z Limit | The maximum elevation difference between a sink and its pour point to be filled. Unless a value is specified for this parameter, all sinks will be filled, regardless of depth. The value for Z Limit must be greater than zero. |