Check Files zln zpt check P

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The _zln_zpt_check.mif or _zln_zpt_check_P.shp is only created if a Read GIS Z Line == command has been specified in the model. This file contains information on the elevations points (zpts) that have been altered by the Read GIS Z Line commands.
The attributes of the zln_zpt_check layer are provided in the following table.

Attribute Name Attribute Description
dz The amount by which the elevation has been changed by the Z Line. A positive value indicates that the elevation has been increased by the GIS layer and a negative value indicates that the elevation has been lowered. For example a value of 0.3 would indicate that elevation point has been raised by 0.3 (metres or feet if running in US Customary units.)
Elevation The elevation after the zpt has been modified.
Source The path to the GIS layer which has caused the elevation point to be modified.

Note: more than one Z Line layer can modify the same elevation point. For example if two breaklines are applied which intersect then the later occurrence in the geometry control file is given preference. In the _zln_zpt check file both modifications are reported. The final elevations are reported in the mesh check file.

A symbology can be applied to the dz attribute to allow quick review of input topographic updates using the Read GIS Z Line commands. Typically three styles are applied as follows:

  • A grey cross indicates that no change has occurred.
  • A black triangle pointing down indicates that the zpt has been lowered
  • A pink triangle pointing up indicates that the zpt has been raised

The first of the following two images shows the use of combined point and line 2d_zln input layers.
ZLines Input.png

The second the output check file showing the change in elevation at each modified cell centroid.
ZLines Check.png

You can follow this link to return the TUFLOW FV Check Files page.