Ask A Cartographer

parcel number label with multiple counties

October 14 2009 | 0 comments
Categories: ArcGIS Methods, Labeling, Map Data, Maplex

I have parcels for 65 Counties covering 23 States and growing (over 6 million records). I am serving them up via a web application. I am trying to figure out the best way to label with parcel number, but not spend a decade making sure there are no duplicates, overlaps, and so on. What would be the best way to allow labeling of parcel numbers for such a large coverage area? Labeling parcels for a single county would take some time, but for this scale it seems impossible not to clutter the map with a billion labels. I am only turning on labels at a 1:10000 scale.

Mapping Center Answer:

We talked a good bit about this very topic when we were assembling the templates for the maps in the Land Records Resource Center.

In the end, we determined that we did not have the solution we needed yet. Independently, we've been working on a tool to batch generate annotation in tiles over relatively large areas.  We tested it out on the World Topographic Map and while we could avoid some tile boundary artifacts, we could not avoid all of them, easily. 

1:10,000 is still quite small in terms of putting all the parcel IDs on an online map.  We've generally started showing them at 1:2,400, and even at 1:1,000 smaller residential lots that can still get a little crowded. 

The main issue for batching annotation or just labeling on the fly while caching a parcel map is the parcels at the edges and corners of each super tile (ArcGIS Server blog entry explaining super tiles: http://blogs.esri.com/Dev/blogs/arcgisserver/archive/2009/02/05/Tips-for-caching-by-feature-class.aspx). Maplex is aggressive and will label any area that it can fit a label inside including the visible portion of a polygon at the display edge (which also has it's geometry clipped just beyond the display edge). 

One trick is to add a background to the label that is a marker symbol with No Color assigned--make the marker symbol something like 250% or 300% the size of the text--that will keep labels off the worst cases.

So, we're still working on how to do this better.

If you would like to post a comment, please login.

Contact Us | Legal | Privacy |