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I live in a coastal area with lots of islands. Sometimes with a black and white map it's hard to distinguish land from sea. So I'm trying to replicate this old map's style. Old Map with offset coastline

I'm trying to do this in QGIS but if it's easier in ArcGIS I'd be happy to hear how to do it in there as well. At first I tried to make multiple simple lines and offset the duplicates but it offsets them inside as well as outside. So then I made an SVG with offset lines and I got closer to what I'm aiming for but since the SVG is a rectangle shape there are gaps and overlaps at every angle. QGIS attempt

Does anyone have any tips?

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6 Answers 6

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Thank you for the link but the tutorial was assuming ArcInfo license. There was a comment that included instructions for how to do it with only ArcView but I figured it out pretty much with QGIS.

I just made successively bigger borders, alternating between black-fill/black-border, and white-fill/white-border. Cartographic Tidal Zones

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I've been playing with something similar recently in Inkscape. Here you can achieve the similar by extending object's stroke (e.g. you go from 1px to 1.5 -> 2.0 -> 2.5 etc.). It does look really nice I think. Old map style

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These are called Tint Bands in the Cartographic world.

ArcGIS can created them with Buffer Tool (pre Cartographic Representations)

Now you can use Carto Reps and tint gradients patterns

ArcGIS Old Way http://blogs.esri.com/esri/arcgis/2009/03/06/quick-tint-bands/

enter image description here

New way http://blogs.esri.com/esri/arcgis/2007/04/17/how-to-produce-tint-bands-for-boundaries/

enter image description here

QGIS (v2.2)

enter image description here

http://anitagraser.com/2011/08/08/creating-a-gradient-fill-for-polygons-in-qgis/

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  • I saw this question and almost flagged it as a duplicate of gis.stackexchange.com/questions/13233/… but didn't since he was referring to basically buffered lines rather than gradients (hard to see in the posted images).
    – Chris W
    May 5, 2014 at 20:03
  • @mapperz wouldn't these examples be for a 'water polygon' that you're symbolizing with interior rings - rather than a 'land polygon' that you're symbolizing with external rings / buffers? May 5, 2014 at 20:41
  • @mapBaker depends on the desired effect can be used either way for gradient tints.
    – Mapperz
    May 5, 2014 at 21:08
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You ought to check out this blog post from Esri. Basically, it demonstrates how to accomplish what you're after using multiple buffers. Obviously it uses ArcGIS for the screenshots, but it would be fairly easy to simply run the Buffer(s) tool in QGIS and apply transparency levels to get a nice result.

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A Cartography professor of mine once showed me maps like this and said "this is where the buffer tool came from". Based on this, and the reference to an ArcGIS 'Ask A Cartographer' article, I'd suggest creating a multi-ring buffer polygon that you can use to symbolize this data.

However - there appears to be no ability to do a multi-ring buffer in QGIS short of creating multiple buffer polygons one at a time, then merging them together and symbolizing them together.

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This can be easily achieved with the "Multi-Ring Bufffer (Constant Distance)" tool. You need to first dissolve your features (mainland and islands) into a single feature to achieve the desired effect.

Select all your features, copy them into a temporary scratch layer and run "Dissolve" on them to join them into a single feature. Then run multi-ring buffer with your desired distance between rings (in my case, I used 0,03 degrees) and create 10-30 rings.

enter image description here

The newly created layer has a column with the ring distance which you will use for styling. You want the ring closest to the shore to be thicker and then for rings to get progressively thinner. Choose a transparent fill color or no brush, then on stroke width, go to "Data defined override" and Edit, then type the following formula:

1 / "distance" / 20 

Layer styling for water lines

This works for me as I was using degrees, but you may want to adjust, change the 20 for a smaller or bigger number or multiply by another factor to get your desired thicknesses.

Then pick a dot line for the stroke style and you are set!

Buffered water lines

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