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bengibson

Read Zln and Zsh elevation data from DEM Grid

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Hello,

Now the 'Read Grid Zpts' command is available, I wonder whether the elevation information for Z-lines, Z-shapes and the like could be derived during initiation of a TUFLOW model, rather than having to produce points at vertices and query elevation information outside of TUFLOW.

Would it be possible for an extra option to be specified at the end of a given command, e.g. after 'Read GIS Z Line' or 'Read GIS Z Shape', to indicate that elevation data for each vertex on the Z-line or Z-shape should be derived from the underlying grid(s) (e.g. Ascii files). Not only would this reduce external processing, it would also enable amendments to Z-lines or Z-shapes to be quickly implemented rather than having to produce points and re-query elevations for amendments to the line/shape.

Currently if a Z-shape is implemented, the elevation data at vertices is derived from the TUFLOW grid, which may be at a cell size greater than the base DEM. Therefore the proposed approach would derive elevations from the finest resolution data available (the DEM).

The ability to implement -99,999 values to ignore certain vertices would still be important, so I envisage the above command would be optional. Thereby some files could contain polygons/lines with elevation points snapped to them, whilst others could just be polygons/lines that are specified to query elevation values on the fly.

If taken forward, it seems appropriate that the point elevations should be derived from the DEM cell that the point intersects, rather than the interpolation procedure applied for the 'Read Grid Zpts' command.

Thanks,

Ben

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