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#1
kuppsta

kuppsta

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Hey,

hopefully someone can help me with this one. I want to create flood maps for different SLR scenarios.

Data:
contour lines (1m intervals) however coastline is missing (no 0 meter elevation)
and coastline shapefile - however no elevation value at all

I added a new field to the attribute table of the coastline shapefile (elevation = 0)

But when I try to create a TIN I cannot assign a z-value for the coastline shape (the only option available is the "false" option)

It works perfect with just the contours.....

Topo To Raster:
Topo to raster also only works with the contours and when using it with contours and coastline I get this message: An error was encountered while executing TopoToRaster.
("esriGeoAnalyst.GridEngine") Error in reading file Z:\Windows\Luis\coastline_mean_high_tide.shp
Returned error from Topo_To_Grid
Error in executing grid expression
Failed to execute (TopoToRaster_1)

There must be something wrong with the coastline shapefile I assume.... However, I am not able to figure out what it is.
Looking forward to see what I did wrong ;-)

All the best and best wishes from iceland

#2
Dustin Edge

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Hi there

When you use the Edit TIN tool, you have two ways to specify elevations.

If your shapefile is a 3D shapefile (where the elevations are embedded within each vertex of the line) then you can choose either true or false from the 'use_z' column.
When you look at the 'shape' attribute you'll see PolylineZM' or if it's a 2D shapefile you will only see 'Polyline'

The 2nd way is choosing an attribute field from your shapefile as the source of elevations. Which is what you have...

In the attached jpg, you'll notice that for the 1st shapefile I'm getting the heights from the Elevation field but for the 2nd shapefile I'm getting the heights out of the Shape field...
Note the true & false options in the 'use_z' field

Hope this helps

Attached Files


Kind Regards,

Dustin


Dustin Edge
Snr GIS Analyst
AECOM Australia

#3
Dustin Edge

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Have you checked your projections? Maybe the coastline is in another coordinate system?
Kind Regards,

Dustin


Dustin Edge
Snr GIS Analyst
AECOM Australia

#4
Kathi

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If the TIN works well with just the contours, why don't you copy the coastline into the contours shapefile (or a copy of it) and assign it the value 0 for elevation?

(Simply start an editing session for the contours, select the coastline, right-click>copy, right-click>paste.)

I'm assuming here that you work on ArcGIS. Hope this helps.
Cheers,

Kathi




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