Making the most of GIS mapping You can spend a week analyzing a project and destroy the results with a bad map.

Maps “A map is a representation, normally to scale and on a flat medium, of the selection of material or abstract features on, or in relation to, the surface of the Earth.” (International Cartographic Assoc.)

Map objectives –Share information –Highlight relationships –Illustrate analysis results You have several objectives Design objectives –Manipulate the graphic characteristics –Fulfill the intended purpose

Who is your audience?

How are you representing reality? Is a single center line more appropriate than the curb line?

What is the scale of your map?

Scale is very important What is the purpose of the map? At 1:250,000, a 7mm pencil line for a road or stream represents 574 ft. At 1:24,000, a 7mm pencil line is equivalent to 7.87ft.

Detail?

Technical Limits

Mode of Use Travel map Wall Map

There are different map types General maps Topographic maps Show locations Variety of uses Thematic Maps Distribution of an attribute Attribute relationships

You use different design techniques to accomplish different objectives.

The Good, the Bad and the downright Ugly. You can easily avoid making a really ugly map by following some basic map making guidelines. By the way, its usually very easy to spot a novice map maker – bright colors and lots of it, or too many things on the page.

What areas have the highest populations in this map?

What about this map?

Color makes a very big difference. The darker shades, in this case, represent higher values.

Color standards

Intense, primary colors are hard on the eyes and do not attract serious attention. Save it for your T-shirts.

Pastels, or using transparency, is much easier on the eye.

When you make a color map, it is a good idea to print it out in Black and White to see how it looks. Very often your map is going to be copied for wider distribution.

If you are not happy with ESRI color ramps, you can create your own. Choose the colors you want for both ends (double click) Then Click Sym and choose Ramp Colors.

BAD!

Better

The eye cannot typically see more than 7 shades of gray. In reality, we have a hard time with more than 5 shades.

Consider polygon shading but be cautious because it can become very “busy” and hard to read. Many journals require B&W maps for reproduction.

Map Elements Neat line Graticule / Grid North Arrow Legend Title Verbal Scale? Index map Date Author Pertinent Meta Data Scale Bar Representative Fraction (RF)