Hi, I believe I would use gdal_calc https://gdal.org/programs/gdal_calc.html and make the terrain above the sea level flat before creating the contours. And I would avoid shapefiles and use GeoPackage as output format.
There is a button "Edit on GitHub" in the top-right corner on page https://gdal.org/programs/gdal_contour.html, feel free to test it. -Jukka Rahkonen- Stephen Woodbridge-4 wrote > Hi, > > I want to use gdal_contour to generate shapefile contours which is > pretty straight forward except I'm working with coastal relief data that > has both elevation and bathymetry. I only want contours for the > bathymetry. > > I tried setting the -off -5 and -i -5 with the idea that this would > start me at a depth of -5 and generate contours every -5 units deeper, > but the generated an empty files. Seems like -i parameter can not be > negative (should be mentioned in the docs). > > This sets the depth to 400ft and generates contours every 5 ft above that: > > gdal_contour -off -121.92 -i 1.524 bathy-value/crm_vol2.nc.tif > bathy-contours/crm_vol2.nc-5.shp > > How can I stop/limit the process and stop at 0 (ie: sea level)? I don't > want land elevation contours. Like a -limit 0 argument? > > If this can't be done, it would be a nice option to have so you can > breakup contours into multiple shapefiles to avoid overflowing them > > Thanks, > -Steve -- Sent from: http://osgeo-org.1560.x6.nabble.com/GDAL-Dev-f3742093.html _______________________________________________ gdal-dev mailing list [email protected] https://lists.osgeo.org/mailman/listinfo/gdal-dev
