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Performance and layer management strategies for layers that display more data as you zoom in

August 24 2007 | 0 comments
Categories: ArcGIS Methods, Cartographic Representations, Labeling, Symbology

We are trying to create a template with preloaded scale dependent data. One example is our stream network. We want only the major rivers to be displayed when we are making small scale maps. As we zoom in we would like to display the tributaries and canals and so on. We would like to only use one feature class to do this. Rather than make a layer file for each scale range. If layer files is the only way to do this, is there any performance loss in displaying the data this way?

We would like to use standard symbology with all our maps as well. I believe cartographic representations is that answer for that.

We would also like to have labeling standardized. Any way to do this without creating annotation?

Mapping Center Answer:

Using one feature class should work fine; in fact You’ll have to provide an attribute for your cartographic stream order and populate it yourself; though we had an intern do this for a dataset comprising three counties in this summer; it took about 8 hours; using progressively smaller hydrologic units to guide his selections.

You will, however, have to use multiple layers, each with a definition query that filters the features for each scale range. There’s no performance hit on using layer files; the definition queries are appended to the draw requests, so only the minimum number of features are returned. From a map and TOC management perspective, I would put these layers inside of a group layer. That way the end user can control visibility with just one layer control.

As for standardized symbology, I think representations are a good route to take, and will likely save you a little bit of time over the standard way of managing symbols in layers.

Labeling, on the other hand will be hard to standardize without using annotation, particularly multiple annotation classes (one for each scale). Using Maplex would certainly give you better quality labels (more in standard positions), but could not guarantee standardization between scales. In 9.3 we are adding a checkbox for labeling rivers (similar to how we have one for streets now), and so that should also make things a little more standard.

It sounds like you’re on the right track, good luck,

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