How to Map 1: Housekeeping

Before we get down to the real business of map-making, there are some things you should know that’ll save you time later.  A couple of bits of housekeeping, let’s say.  Point 1:

Get your files organised

For some technical reason I don’t understand, ArcMap doesn’t like it when you save your files in My Documents – I think of it as ArcMap being too busy to faff around sifting through all your old school work to find shapefiles and the like, so we make it easy for the old guy by saving all our GIS files to the C: drive, i.e. to hard disk.

Continuing the ArcMap-as-pernickety-elderly-fella analogy, it also gets terribly irritated if you change your file or folder names.  This is because the links made in ArcMap (that will make more sense later) aren’t live, meaning they don’t update themselves.  So if you change a file or folder name ArcMap gets confused with the pathway it’s supposed to be following and it loses the data.  It’s remediable, but a pain, so best to avoid doing that.

The point of all this is: keep your GIS folders and files obsessively well organised, and keep them all on the C: drive.

When this is applicable later I’ll mention it so you remember.

A note about shapefiles

I just mentioned shapefiles and seeing as they’re what we’ll be using for the whole of this process, I think I should explain myself.  Initially shapefiles look intimidating, but don’t freak, soon you and shapefiles are gonna be best buds.

Officially a shapefile is “a vector data (points, lines, or polygons) storage format for storing the location, shape, and attributes of geographic features. A shapefile is stored in a set of related files and contains one feature class”.

Simply put, it’s the kind of file that maps are saved as.  When you’re browsing files within ArcMap, a shapefile will appear like one tidy little file with a cute green icon.  If you’re looking elsewhere in your computer, e.g. via the C: drive, the shapefile will be revealed in its true form: a group of six files which combine to make a shape or map.

These six files will all have the same name but with a different suffix.  These are:

–          .dbf

–          .prj

–          .sbn

–          .sbx

–          .shp

–          .shx

Now we’ve got that straight, we can begin.  Click to go to How to Map 2: The Map Outline.

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