Creating symbology for multiple attributes within the same feature class in ArcMap 10

Question

I'm struggling to find a way to take a single point feature class that has multiple attributes that I want as feature layers with unique symbology. Let's call these attributes Depth1 and Depth2. A key point here is I want to apply a lyr setting to automate the symbology of each layer and it seems what may be the best way of doing this is in the properties of an output in model builder you can add a lyr file to use as symbology. But I'm not sure how I can get these two attributes as new layers using model builder and then default to correct attribute for the symbology for each (ie. Depth1 for first layer & Depth2 for the 2nd layer). Any ideas? Let me know if I need to explain any of this better.

Answer 1

From your description it sounds like you could use Apply Symbology From Layer tool from the Data Management toolbox. The field names for your input feature layers need to be stable -- meaning the field to use for unique symbols in layer1 will always be Depth1, layer2 ...Depth2 and so on. You'll need a source layer file for each kind of symbology you wish to apply.

If you've already tried this route and it doesn't work, we'll need more specifics about you're attempting to do in order to help.

Answer 2

Since you're dealing with depths, a different and natural approach would be to vary transparency according to the depth. To do this

• add a Transparency field to your feature class (short integer).
• Use field calculator to fill the values (0-100) based on depths, e.g. 'DEPTH' LIKE '-100' = 75, 'DEPTH' LIKE '-200' = 50, etc...
  (Alternatively convert the depths to percentages with something like (100 * ([OldField] - <OldField Minimum>)) / (<OldField Maximum> - <OldField Minimum>) [ref])
• in Arcmap symbology for the feature class pick a single colour, then use the Advanced button at lower right to apply transparency for each feature based on the Transparency field.

I'm not at my computer now so can't verify, but a niggling though tells me this might only be available for polygons, in which case you'd need to buffer your points first to use it.

Answer 3

I'm not sure whether Model Builder allows this level of logical control ("for iteration 1 use field 1, for iteration 2 use field 2", etc).

A Python script may be the better option as it will certainly allow you to handle this. If you search on something like "arcgis python if statement" it should give you some ideas of how to get started.