Multiple contour intervals in a single Map

[Gururaj]

Hi, 

I have recently started to use WAsP software. I see that in the example site assessment like Forssa,, the map has varying contour intervals. Also, I read accross a document that, the rule of thumb followed is : contour interval should be small (≤ 10 m) close to calculation sites, whereas the contour interval can be larger further away from these sites (≥ 10 m). But I am unaware how to get different intervals in the same map. 

Any guidance on the above topic would be very helpful. 

 

Best Regards,

Gururaj

[Mark Kelly]

Hello,

that "rule of thumb" was intended to simply ensure that for WAsP calculations there is adequate resolution of the terrain.
It is merely stating that for increasing distances farther away from the site(s) of interest, the vertical resolution of the terrain elevation data becomes less crucial (not as fine resolution needed at distances >4-5km away from the site).

Although one could draw contours in Map Editor in order to make the vertical resolution finer in the region of interest, doing such "manual interpolation" can be time consuming (and is typically not recommended, unless the engineer decides they can do this reasonably and quickly enough).
There are numerous sources for maps, and other map-processing utilities (e.g. qGIS, Surfer, etc.) which may be used to do operations which produce vertical interpolation or height contours or pixels.  Nowadays most digital elevation maps have resolutions fine enough (∆z<10m).

with kind regards,
--Mark Kelly, Assoc. Prof., Wind Energy Dept., Danish Technical University

Edited January 5, 2022 by Mark Kelly

[Gururaj]

Hi Mark,

Thank you very much for your clarification and guidance. I shall keep a contour interval ∆z value around 5m all throughout the map while generating the contours in qGIS to save time in manual editing.

 

Best Regards,

Gururaj