Mapping Center

This post, is to announce the release of a map template for historical GIS called Historical GIS:  Boston 1775. If you’ve never given historical GIS a second, or a first thought, you might find the contents interesting and maybe even applicable to your work. Consider that the vast majority of GIS data is historical, even if it’s only a few minutes old. Read More...

Most maps should have some depiction of hydrography.  The problem is, if you're not familiar with the data or the typical symbology conventions, it is hard to find the time to make the required effort. 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...

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...

Not long ago we found a workflow that demonstrated how convenient it would be to be able to copy a representation class. The situation arose as we were creating a map service for a map that had been designed for print. The problem was that many of the symbols were too small and detailed to be seen clearly on screen. Our symbols were already cartographic representations, so we didn't want to edit them (to make them larger) because we still needed them to produce our print map. We also didn't want to have to create and manage an extra copy of our data just to manage one additional attribute (the one added for representations). Read More...

Put yourself in the shoes of one of my interns, who was asked to use representations to replicate a 1:100,000 scale geologic map.  In less than two weeks she got it done, and did so well that the next thing I asked her to do was to test ArcGIS Server and make a map service with her map. Those intricate little point symbols on geologic maps that are rotated by their strike angles and labeled with their dip angles were just too small to be seen clearly on screen.  We needed to make them bigger. 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...

Last week we received a good question on Ask a Cartographer: is there a way to create parcel hooks with ArcGIS 9.2? After first discovering what parcel hooks were and finding an example of a typical case (shown at left), the answer seemed like a ‘no-brainer'. Sure, just use the line decoration option on a marker line representation. However, after acquiring some parcel data that included parcel hooks (thanks to Greene County, NC) and seeing the circumstances where parcel hooks (they're also called land hooks or parcel ties) are placed on maps, I learned there are are several scenarios that need to be handled. 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...