James Cheshire UCL CASA

Making Maps with ArcGISArcGIS is one of the most advanced and widely used software packages out there for GIS and spatial analysis. There are many alternatives available, such as MapInfo, or QGIS (this is completely free) but they all share the same principles.

First up go to https://www.dropbox.com/s/ijda6lqfxdfsb14/GIS_intro_data.zip and download the file. Unzip it and place the contents into a folder you can easily find. Call the folder “intro_GIS” or something similar.

Click on “Start” and open ArcGIS. You should (eventually) get something that looks like the below. If you are using older versions of ArcGIS then you have something a little more retro.

As you can see, there is not a huge amount to look at. The buttons along the top are the most important things to note at this stage.

The next step is to load in some interesting data, in this case about sports participation in London. Click on the “Add data” button (black cross above) and

navigate to the folder where you saved the downloaded files.

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James Cheshire UCL CASA

Select the file and click “Add”. You should get something like this:

It is a map of the London Boroughs (their borders have been simplified a little). Apart from the map you should also spot that there is now a file listed on the left in the area of the screen known as the “Table of Contents”. This is where all the layers in the map get added and where you can access the data they contain.

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James Cheshire UCL CASA

The map is not simply the geometry of London Boroughs. There is also a table that contains data about each borough. Each of piece of data is known as an “attribute” and these are stored in the “Attribute Table”. To see what this contains for the london_sport layer right click on in it and then click on “Open Attribute Table”.

This should then open a table of values…

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James Cheshire UCL CASA

In this example, each London Borough has 6 attributes - one for each column. The two we are interested in here are the “Partic_Per” and “Pop_2001” attributes. The former refers to the percentage of the population regularly participating in sport and the second is the total population for each borough. We can use these values to colour our map. Close the attribute table window and right click again on the london_sport layer. This time click on the “Properties” button.

This will open another window that contains a range of parameters about how the layer will look in addition to other parameters. If you click on the “Symbology” tab along the top, you will see a list of options on the left. Here we

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James Cheshire UCL CASA

are dealing with “Quantities” (as opposed to nominal/categorical data), and we want to use “Graduated Colours”.

In the “Value” field select “Partic_Per” in the dropdown. You can then select the “Colour Ramp” and select the colours your would like to use.

Once you have done this click “OK”. I selected a blue palette:

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James Cheshire UCL CASA

If that is all we want to do, we can add some final adornments and export the map as an image or PDF. At the bottom of the window there should be a couple of

small buttons.

These let you toggle between the “Data View” and “Layout View”. The Data View is the one used for the analysis and preparation of the map whilst the Layout View is similar to a print preview screen. It also enables you to add a title, scale bar and key to the map. Click on the layout view button and you should get the map as it appears on a sheet of paper. To minimise the white space we can make the page landscape by going to File-> Page and Print Setup and selecting landscape as the orientation. The maps border will still be configured as if it were portrait so you should resize it by selecting the border and dragging it to shape in the same way that you would do for images in Powerpoint or Word.

In the Layout View you have two different types of zoom.

Those underlined in purple are the ones we used above to zoom in and out of the map, whereas those underlined in green zoom in and out of the page. Experiment with these to get what I mean and position your map in the centre of the page as large as possible.

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You are now ready to add map adornments, such as the title and legend. These are available from the “Insert” menu at the top of the window and can only be seen if you are in the Layout View.

Lets first click Insert-> Title. Give the map a sensible name. You can drag the title to reposition it. If you double click on it you will get a dialogue box that enables you to change the text and clicking the “Change Symbol” button will give you the option to change the font/ size/ colour of the text. The next step is to add a legend by clicking Insert-> Legend to bring up the “Legend Wizard”.

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James Cheshire UCL CASA

Make sure that london_sport is in the “Legend Items” box and click next. Change the “Legend Title” to “% Sports Participation” and keep clicking next until

finished.

As you can see above, the end result isn’t great so we have to make a couple of improvements. First, double click on the legend you just created and then on the “Items” tab. You should see a “Style” button if you click on this it offers a range of options to change what is included in the legend, I like to keep things simple by only including the label rather than the layer name and description.

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James Cheshire UCL CASA

Next, we need to remove the excess decimal places. This is done via the layer properties options. Right click on the london_sport layer in the Table of Contents and navigate back to the “Symbology” tab. Right click where the values are and then click “Format Labels”.

You should then be given the option to specify the number of decimal places or significant digits. Reduce this value to 1 and click OK to return to the map. You should then see a much better looking key.

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James Cheshire UCL CASA

Click Insert-> North Arrow and then Insert-> Scale Bar to add these annotations. As you can see there are a lot of choices for these. Double clicking once they have been added to the map allows for further customization.

Finally to export your final map for printing go to File-> Export Map and select the format you would like. I would recommend wither PDF or PNG and make sure your “Resolution” is 300 or so if you wish to produce high quality prints from the map.

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James Cheshire UCL CASA

Now repeat these steps to produce a map of the population for each London Borough.

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