Mapping Center

Tree symbols are a great way to enhance the appearance of a large scale, detailed map. To make attractive point symbols for trees, you need a good place to start from and thankfully all of us ArcGIS users have that. Using multi-layer character marker sybmols, the variety of tree symbols you can create is endless. This blog is meant to introduce (or reintroduce) you to the ESRI US Forestry 2 font. It is also meant to give you some tips for creating a variety of tree symbols to use on your maps. Read More...

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 frequently come across data which has lost data links (a red !). This occurs when the data has been moved or no longer exists, thus breaking the link. On some occasions, even after I tracked down the data and repaired the data source, the symbology still didn’t draw -- it exists, but the wrong field is listed on the Layer Properties Symbology tab. Usually the draw category (Value field) has defaulted to a non-matching field. Simply changing the Value field does not do the trick. Read More...

It is often useful to use a hillshade raster to show terrain to support other information in a map such as an analytical surface like population density, or a thematic overlay like soils. There is one significant problem with this; however, which is that the shading from the hillshade modifies the colors of the main information layer making them artificially dark or washed out. That makes map reading and applying what you learn from a legend a frustrating task. For example, the legend for the map on the left is shown at the right--it's hard to figure anything out with so many similar colors in the legend and the added effect of varied gray tones within each soil polygon on the map. (One way you can help your map readers is to 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...

If you're making a map that is either a large format print map or a map that will be served via ArcGIS Server, squeezing every bit of wasted time out of drawing performance is critical. Don't get tired of sitting there drinking extra cups of coffee watching the word "Drawing", all your layer names, and that little blue globe. If you're finding it stressful to explain when updates will be coming, or the timing for caching the map you are serving, or your map services generate complaints about poor performance, then try the two tips in this entry. Read More...

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. Read More...

Keeping track of scale ranges at which a layer will be visible when a map has a few scale ranges and dozens of other layers can quickly become mind-boggling. This entry describes a strategy for using ArcMap's Table Of Contents (TOC) to create these maps and effectively manage all those layers and scales. Read More...

One issue we hear about from the folks who teach cartography with ArcGIS is that users who are new to ArcGIS have some frustration in learning how to make minor customizations to symbols in the style files that come with ArcGIS. For example, removing a layer from a multi-layer symbol, changing the color of part of a multi-layer symbol, or other minor edits that (in theory) ought to be easy to figure out how to do. Read More...

This question comes in fairly regularly at Ask A Cartographer, so I felt it was time to add a brief blog to use for future queries.  This issue is a common one, and is the topic of a Knowledge Base article that describes the basic steps needed to solve the problem.  The value added here is a bit more discussion as to why this is a necessary workflow. Read More...

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...

Depicting natural areas such as vegetation or complex hydrography such as swamps and estuaries can be accomplished by merely using solid green fill and blue fill symbols. However, such symbols are arguably bland, and certainly do not convey relative density, ruggedness, or texture. 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...

Symbolizing road overpasses or underpasses typically requires that you perform two data preparation steps.  First, identify which roads overpass other roads.  This may be very simple intersections between two roads, or it may include many other roads when dealing with complex highway interchanges.  Second, represent the interchanges clearly.  This task may mean simply changing feature or layer drawing order, or it can also mean knocking out or masking portions of underpassing features.  The image to the left shows the underpassing highway being masked by an overpassing street and railroad. Read More...