Mapping Center

We’ve posted our recently revised Color Ramps version 2.0 styles on our site to be more suitable for your use. Our impetus was we needed something new to work on a project with the topic of Washington Landforms and it is specific to printed maps. This is a map that we will talk about in our "One Minute Cartographer" session at the ESRI User Conference this year. This presentation will be posted on the Mapping Center - Other Resources page after the conference. The color ramp used on this map was selected from the PNW_x set in the new Hypsometry style. (PNW stands for "Pacific Northwest".) Read More...

I was recently asked to lend a cartographic hand to a project my agency is working on. I work for OregonMetro (the Metropolitan Planning Agency in the Portland, Oregon area) and among other things, we are charged with planning the future of the region. One of the facets of the planning program involves helping the 25 cities in our jurisdiction collaboratively plan for future growth. We have identified 39 urban centers and we defined a list of urban amenities that have been shown to have a positive impact on residential pricing and convenience or family-oriented amenities. These include the following: Read More...

Last week we received a request for blog entry on a 3D effect we could provide for displaying building footprints using cartographic representations. The most common, and simplest effect is to add a drop shadow like what is shown in the image to the right. Read More...

Buffer vignettes symbolize the interface between two areas. They are often used to show the land-water interface by gradually fading blue at the coast into white or vice versa. You can also use them to fade the map out into a white background. These types of vignettes are created using buffers that are symbolized in a special way.

Note -- as described this only works on white backgrounds. See the two examples at the end to see how the data frame's background can be coordinated with the buffer vignette for different effects on along coastlines. Read More...

Yesterday I got an email from a long time colleague showing me an online map and asking, “When will it be possible to do this map with ArcGIS”? The map is the interactive map of Washington DC at http://dc.everyblock.com. In particular my friend was looking at the crime map wondering how the proportional symbols showing crimes became disaggregated as he zoomed in, eventually showing individual crime sites. Read More...

One of the most frequently recurring topics on Mapping Center is what to do with stacks or clusters of point features on maps. In August 2007, I wrote a blog posting on how to use Maplex to display coincident points, and this worked for some scenarios, but not all. Read More...

We got a good question on Ask a Cartographer this morning.  The gist of the question was how to go about symbolizing street centerlines so they could be drawn using line symbol widths that reflected, at scale, the actual width of the road (as shown in the image to the left). This is a good cartographic solution because varying the line width adds hierarchy to the roads -otherwise it would be hard for you map reader to know which are wider or more heavily used. Read More...

Not too long ago we received a question on Ask a Cartographer about symbolizing polygons with a scalloped edge (like the old ArcInfo hardwire line symbol). Hoping to do better (scallop lines were a nice idea, but they didn't always turn out as good as I would have liked, so I rarely used them), I started experimenting with the options in representation symbology. I'm happy to report that there is a better solution. Read More...

After seeing my poster that described using dot maps to show soils at the AAG conference in Boston a few weeks ago, Charlie Frye suggested that I write this entry to describe my maps and the technique used to create them.  This seemed especially appropriate given the recent entries in this blog about dot maps. Read More...

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. Read More...

Several weeks ago, after a colloquium given by Dr. Aileen Buckley on the devolution of cartographic theory, we approached her about research opportunities that she mentioned. She was glad to accept our help and put us in contact with Dr. A. Jon Kimerling from the Oregon State University. The research he was undertaking during his sabbatical in Redlands, CA dealt with a particular mapping method in the cartographer's bag of tricks - dot density mapping. After discussing the research issues with Dr. Kimerling, we were tasked with developing a series of maps to supplement his research Read More...

Text and imagery have had an uneasy relationship since the day they met.  Satellite imagery and aerial photographs are the ultimate variable background, which makes any text drawn on them hard to read. Read More...

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. Read More...

The map excerpt shown at right (click on it to see the details) shows an example of hollow cased roads.  The map is from a mosaic of USGS DRG image files.  The map specification requires that the cased road symbol contains a transparent gap.  The examples shown below were created with ArcMap 9.2 and used cartographic representations to re-create the effect on the USGS DRG map. Read More...

The illustration at left shows a map the Paris Metro system (RATP).  The routes are depicted in a schematic view and this kind of map is challenging to create because multiple routes may share the same path, for example multiple bus routes along a single road or track. When this happens, the coincident routes are offset in a fashion that makes it possible to understand the path each route is taking. When using ArcMap and line features for the routes, the coincident features draw on top of one another, making it difficult to visualize. Read More...