Tag: Cartographic Design

Symbolizing rivers and streams with proportional symbols

By Charlie Frye, Esri Chief Cartographer

Last week we received an interesting question on Ask a Cartographer about how to create tapered stream or river line symbols. Tapered symbols are actually a bit more complicated than what is shown to the left; those lines are proportionally scaled symbols that are based on an attribute value. Notice that each stream is a single line width.  Tapered symbols would actually change widths along the length of a given feature, giving a very smooth effect. Tapering is more useful for depicting flows that range widely in value or magnitude, whereas proportional symbols are usually an excellent solution for symbolizing rivers and streams.  Continue reading

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Dot density mapping with ArcMap: Part 2–Defining exclusions and inclusions

By Daniel Smith and Alex Quintero, University of Redlands, Masters of Science In GIS Program

Exclusions Inclusions Part 2 - Thumbnail

In the first dot density mapping blog, we discussed the workflow for creating dot density maps using ArcMap.  In that discussion we emphasized the need for using exclusion or inclusion layers.  Here is an example of how we set up the inclusion and exclusion choices for mapping population density in San Bernardino County, the county with the largest land area in the conterminous United States. Because of its size and the fact that population is not evenly distributed throughout the county (rather, it is concentrated in the southwest corner, around where Redlands is located), this county exemplifies the limitations of dot density mapping without inclusions/exclusions when mapping population density at the county, the state or even the country level. Continue reading

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Dot maps vs. choropleth maps with random dot area symbols

By Dr. A Jon Kimerling, Professor Emeritus, Oregon State University

Question: What is the difference between filling a polygon with randomly placed dots and creating a dot density map for the polygon?

Filling a polygon with a certain number of randomly placed dots is a form of choropleth mapping where random dots are the area symbol for a quantity that is assumed to be of uniform density throughout the polygon. The choropleth map seen below of San Bernardino county population density uses random dots in this manner. Continue reading

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Cartographic design: Legends

By Aileen Buckley, Mapping Center Lead

Example of items in a legend

We recently received a question about legends on Ask a Cartographer, so I thought we should post a blog describing some of the cartographic guidelines for legends that may help you make decisions about their design.  Here are some tips — first related to page titles and legend titles, then some that are more general, and finally related to grouping items in legends: Continue reading

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Cartographic design: Inset maps

By Aileen Buckley, Mapping Center Lead

Recently we were asked if there are any cartographic standards for inset maps. Here are a few guidelines:

Purpose

First, consider why the inset map is needed. Inset maps are sometimes used to show related themes of data at smaller scales, for example: Continue reading

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Esri Press presents Designed Maps: A sourcebook for GIS users by Cynthia Brewer

By Michael Law, Esri Product Engineer

Link to Esri Press webpage for Design Maps

Cynthia Brewer’s new book titled Designed Maps: A Sourcebook for GIS Users is a companion piece designed to compliment the highly successful Designing Better Maps: A Guide for GIS Users published by Esri Press in 2005. The goal of the book is to offer a graphics-intensive presentation of published maps, providing cartographic details that will prompt GIS users to think about their own maps and how to improve them. Continue reading

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Guidelines for minimum size for text and symbols on maps

By Aileen Buckley, Mapping Center Lead

There are some general guidelines you can follow regarding the size of text and symbols on a map.  The key is legibility – that is, ability to be seen AND recognized.  Legibility can be affected by:

  • Size of symbols and type
  • Contrasting colors and shapes
  • Familiarity
  • Perfect vision and perfect viewing conditions Continue reading
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Choosing color ramps and displaying for hillshade rasters

By Charlie Frye, Esri Chief Cartographer

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Using ArcMap to symbolize a hillshade raster layer (the output of the Spatial or 3D Analyst’s Hillshade tool) is pretty straightforward, and the default symbology (black to white ramp) doesn’t look too bad. In fact, if your hillshade layer is the only layer in your map, and if you don’t mind not seeing some of the details that have been visually absorbed into the darker tones, the default symbology is okay. To be fair, the default symbology for hillshades is useful for much more than just terrain depictions, so it’s good to know what might be helpful when depicting terrain with a hillshade. The image to the left is an example of a hillshade using the default color ramp. Continue reading

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Tips for exporting to Adobe Illustrator format (AI) so CYMK colors are maintained

By Michael Law, Esri Product Engineer

Color Selector showing the menu that is shown be black triangle button.

For many GIS users and cartographers, the use of external graphics software is a common step in his or her workflow and production of print quality maps. One of ArcMap’s more popular export formats is the Adobe Illustrator (AI) export because of its wide compatibility with a number of graphics software packages. This export format was first made available in ArcGIS 8.1 Service Pack 1 and has been popular ever since. The ArcMap AI exporter has been fully tested to work in Adobe Illustrator CS and CS2. It is currently being tested in CS3 with good initial results. Continue reading

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Verbal scales

By Aileen Buckley, Mapping Center Lead

Verbal Scales - Thumbnail

A verbal scale is also referred to as a “word statement” or a “scale expression”, and in the ArcGIS software, it is one of the options for inserting “scale text”. It is offered in the form of a relationship between map distance and ground distance stated in standard units that we understand for both sides of the relation. For example, if we say that a map that is “one inch to the mile”, we understand (at least in the U.S.) the units on both sides of the relation. This is the same as a map that is 1:63,360, but for many map makers and map users, we will often translate this mentally into “one inch to the mile” because we can intuit that more easily (figure 1). Continue reading

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