Viewing 3 posts - 1 through 3 (of 3 total)
  • Author
    Posts
  • #28202

    Juanjo
    Participant

    Hi,
    I am trying to improve Sierra del Cuera sector in OSM. This is a karstic massif in the North of Spain and therefore it is plagued of depressions/sinks.
    OpenAndroMaps renders depressions contour lines the same way as normal ones with the consequence that one can think there is a hill where in reality there is a depression.
    Would it be possible to somehow tag depression contours as such and distinguish them on the map from other contour lines by hachures marked on the downslope?
    Regards

    • This topic was modified 1 year, 10 months ago by  Juanjo.
    #28217
    ChristianK
    ChristianK
    Keymaster

    Would it be possible to somehow tag depression contours as such and distinguish them on the map from other contour lines by hachures marked on the downslope?

    Hi,

    Unfortunately this is not possible.
    These Contourlines are simple ways in the maps.

    BUT:
    If you enable hillshading in Locus/Orux you see the depression – this is calculated in both Apps by downloaded SRTM/HGT – files.

    Best regards
    Christian

    #28219

    Juanjo
    Participant

    BUT:
    If you enable hillshading in Locus/Orux you see the depression – this is calculated in both Apps by downloaded SRTM/HGT – files.

    Hi Christian,

    this is what I do, I do use SRTM data provided by Sonny, but still, at this resolution (+- 30m) is not obvious to see the depressions let alone the sinks.

    Just to give you an idea of the complexity of the terrain, I attach a screenshot where hillshading is done using a 5m DEM.

    I don’t know which tool do you use to generate the contour lines … but gdal_contour documentation states ‘Starting from version 1.7 the contour line-strings will be oriented consistently. The high side will be on the right, i.e. a line string goes clockwise around a top.’, which makes me think that it will go counter clockwise around a depression.

    If you happen to use GDAL, this may be a starting point.

    Regards

    Screenshot_20190422-193315

    • This reply was modified 1 year, 10 months ago by  Juanjo.
    • This reply was modified 1 year, 10 months ago by  Juanjo.
    • This reply was modified 1 year, 10 months ago by  Juanjo.
Viewing 3 posts - 1 through 3 (of 3 total)

You must be logged in to reply to this topic.