• garycollins24

This Beautiful World Blog 2 | Less is more... | Visualising the Volcanic Island Tenerife

Updated: Oct 16, 2020


Welcome to my second blog in the series "This Beautiful World", where I will cover what I learnt from creating my viz of the Volcanic Island Tenerife. If you missed the first blog and introduction to this Blog series, I suggest you read this first.

This was one of my early vizzes using mapbox, and my learning objective on this viz was to learn how small changes to colour and detail and really make a map POP! Up until this point I have only used the standard mapping options in Tableau.

The Thinking Behind the Viz


One of the key takeaways I took from Jonny Walkers excellent webinar on Mapbox was that when it comes to maps and making them POP, ‘less is most definitely more’. You can achieve dramatic changes in the way a map feels with just a couple of point moves of saturation, colour or shading.

I saw Johnny’s passion about the details of a map come though, and I knew this was clearly the secret sauce in how he performs such magic in Mapbox. So, I needed to find a way to experiment with this. I had a search about the globe on Mapbox, looking for a place with lots of intricate details that I could experiment with very subtle colour changes, and the effect they would have. I ended up looking at the volcanic Canary Islands and thought, perfect! Volcanic Islands – there must be lots of craggy details to experiment with – and there was!

Building the Viz


In many respects, this is one of the simplest things I have done in Mapbox, but it really demonstrated to me around how ‘less is more’, just as Jonni said. In this viz I only used 2 Mapbox layers : the ‘mapbox-terrain-rgb ‘layer and then a group of 10 grouped ‘Hillshade’ layers to give some very subtle shading.

First off, for those that haven’t heard about Mapbox, it is an excellent online mapping tool, which is free to use. You are able to make beautiful maps in Mapbox, and then use these visualisations in a dashboard directly in Tableau. Tableau can connect directly to Mapbox to visualise your map. If you haven’t already used Mapbox, I suggest you check it out and create an account (mapbox.com), and have a read of this excellent blog on integrating Mapbox into Tableau (https://docs.mapbox.com/help/troubleshooting/use-custom-mapbox-styles-in-tableau/).

Don’t be daunted by using a separate tool to create a map style you want, and then integrate this into Tableau, it sounds like it could be a lot of work, but once you have your map in Mapbox, it is in Tableau in a few click of the mouse.

So, I am assuming from this point on that you have created your Mapbox account, and have had a look at the blog above to integrate into Tableau.

So, to start building a map in Mapbox, firstly off, enter the Mapbox design studio (bottom right of the screen shot).

Click on the ‘New Style’ blue button.

In Mapbox you can start with either a template style, or a totally blank page. For this viz, I started with a totally blank page.

Once you select ‘blank’ style you can start building your own map. Click on ‘Customize map’ and you will see the following page:

Click on ‘Layers’ in the top left hand corner, and then the ‘add a new layer’ icon ‘+’, you will then see this screen:

In the ‘Active Sources’ list, there is a series of standard mapping data that you can use in your vizzes. You can also download and use other mapping data into Mapbox, but we will cover that in a later blog. As standard Mapbox comes with some great data layers to use.

In the ‘Active Sources’ search bar, search for ‘mapbox-terrain-rbg’ layer and click on it. You should get a screen that looks like this.

At this point, you have selected a layer for a map – this one focused on terrain. Next, search for Tenerife in the search bar on the top right hand corner, and focus in on the island. You should end up with a screen that looks like below.

Next you can start to play with the colours of the terrain in the map. To do this, click on the ‘mapbox-terrain-rgb’ in the top left, just below the ‘+’. Your screen should look like this.

Digging into the colour settings, after much fiddling, here is what I ended up at:

Shadow colour #: a37b7b

Highlight colour #: 1c0d0c

Accent colour #: 0b0805

I kept the Intensity to 1.

This colour gave the really dry feeling of a Volcanic Island I was after:

Adding the second layer of 10 grouped ‘Hillshades’ gave the final effect:

This layer gives both the depth of colour to the image, and also a very subtle shading effect that enabled me to really highlight the ridges in the ground caused by volcanic activity.

In order to create this layer, firstly I selected the Hillshade layer (click on the ‘+’ in the top left of the screen, search in Active Sources for ‘Hillshade’ and select). I then played with the colouring. I went for a sandy type effect, as this felt it would fit for a volcanic and dry island.

The colour number I ended up on was #f6b309. I also lowered to Opacity right down to 0.04 – just enough to give a very subtle feel to what would otherwise be too harsh a colour.

In order to create the very subtle shading effect in the viz to draw out the roughness of the terrain, I duplicated the layer 9 times, and then grouped them together. The duplication and grouping/ungrouping are both in the top left hand corner control panel. In order to get the shading effect, I went into each copy of the Hillside layer, and increased the ‘Translate’ field by an increment for each one. This ‘Translate’ field essentially lets you move the layer by a specified number of pixels (or even a fraction of a pixel).

That was the Mapbox side of the viz complete. After that, I integrated the map into Tableau and created my final viz. Here is the link again on how to do integrate into Tableau for you. It is really simple, just a few mouse clicks.

I spend a lot of time playing with the different colour options in Mapbox, and even with my low level of knowledge, I would really see how such small changes in colour or opacity, and shading with translation could make such a difference. It was addictive playing with it to get just the right look and feel I was after!

Mapbox is an amazing tool, and more amazing that it is totally free. It can really add to your Tableau vizzes – the sky really is the limit.

Well, I hope you have enjoyed the blog, and once you experiment in Mapbox will see how you can change the look and feel of the Map with some subtle changes to the colour settings. Next blog I will be covering off the vizzes I created to add long shadows to a Mapbox map:

See you soon!

@garycollins24

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