Mapping Center

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...

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...

Quite some time ago we posted a blog entry on creating tint bands, which are bands of color either interior or exterior to polygons along their borders.  You will see this cartographic effect on world atlases, for example, using different colors to distinguish the various counties. The solution we presented was involved and complex, but it did preserve essential characteristics of the polygons better than any other method we tried. 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...

Using cartographic representations to make line symbols like those in the image to the right, where markers are displayed in conjunction with a dash pattern, requires more than just casual knowledge of the geometric effects. In fact, to make a line symbol like the one shown to the right, the default settings won't work. Read More...

For the past few years, when time allowed, I've been reconstructing a map of colonial Boston in ArcGIS, using source maps from 1775 to 1784.  The image on the left is an excerpt of one of these maps.  I like a number of the effects that 18th century cartographers had drawn on their maps, including little pictographs for trees (today cartographers call these mimetic symbols).  Anyway, I wanted to add some of these effects to my map.  This posting explains how I showed trees on my map.
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A question was posed on Ask a Cartographer about using representation rules that you have saved in a style in another map on a different layer.  The online help for this topic didn't provide much assistance. The topic on organizing representation rules in a style explained how to load the rules in to a new layer, but it didn't explain how to make use of them, i.e., how to make the features with the newly loaded rule. 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...

This final part of the series will cover using cartographic representations for dashed lines, like the red and white cased lines in the image at the left, and for creating cul-de-sac or squared off ends to streets.  Both of these effects will build on the examples in the previous two portions of this series with one exception.  Because we will be using cartographic representations for the streets, we will be better able to manage line caps and therefore will not need to use the Dissolve tool to dissolve the streets by name, type, and z-level.  The removal of this step is significant because now an extra dataset is not required just to have cartographic quality streets; everything needed for a high quality cartographic depiction of streets can be stored in attributes. This should come as good news to those of you who have mentioned to us, many times, that managing additional datasets for the sake of cartography is not only a data management, but a political hurdle, that you would just as soon not have to deal with. Read More...

A number of maps, particularly those geared towards outdoor tourism, rely on a convention that uses standard icons to list the services or amenities that are available at some place on the map. Using cartographic representations simplifies what used to be a rather unwieldy task from the perspectives of data modeling, data management, and symbology. Read More...

In the United States, the Public Land Survey System (PLSS) is a way of subdividing land. The USGS topographic map symbols for displaying PLSS data are an excellent way to symbolize PLSS data on not only topographic maps, but because the topographic symbols are  so well recognized, the same symbols can be used on many other kinds of maps. In the image to the left, the "plus" marker symbol shows where a found corner is located, however, if no corner has been found, then no marker should be shown, leaving a gap that signifies the doubtful location of the corner. Next we will describe how to use cartographic representations to symbolize township, range, or section lines to leave a gap at the corners, allowing corners to be added (as point features) or gaps to be shown. Read More...

Dash-dot line symbols for polygon outlines should be displayed in a way that consistently shows the pattern of dashes and dots and clearly shows the shape of the polygon. In ArcGIS, a multi-layer line symbol is required. One layer is a cartographic line symbol with a dash pattern.  The second is a marker line symbol that shows a marker (the dot) with a complementary pattern to the dashes. Read More...

Indicating that a street is one-way and which way is valid to travel was a lot harder than it should have been prior to version 9.2.  At 9.2, the new representations symbology makes this a much faster and easier task.  To create this effect, you will need to have your street line data stored in a geodatabase which is a requirement for using representation symbology.

You will also need to have a field in your data that indicates whether a street is one-way. This also depends on the digitized direction of the street lines to align the arrows in the correct direction. If your streets are not digitized correctly, you can edit them by selecting each feature, set the Edit task to Modify Feature, then right click on the feature and choose Flip. Read More...