Help - Different Layers are updating their attributes when changing a field's value in one layer?

[ColeDickison]

So to summarize, our organization has done a 6 month study on water quality at different sites along rivers & streams in our city. I am making a visualization of this in ArcGIS pro, displaying Turbidity on a color ramp for each section of stream.

I have used the create function to trace an already existing rivers layer so I could add all my own attribute fields. This has all been straight forward. Then I duplicated the layers by using "Make layer from selection" and making a layer for each month of the study. Here is the problem, when I update the "October" layer's attribute field for Turbidity, every other instance of this layer is also updated even though they all have separate names and are not in a group. 

Hopefully some has experience with this problem and can help. Thank you! 

[Alfred_Baldenweck]

Hmm.

So, a layer is just a representation of the data. When you duplicate a layer, or make a layer from selection, you're just adding that exact same data to the map again, only possibly dressed a little differently.

It sounds like, rather than creating a new record for each month (using the same geometry), you have the same record presented over and over.

There are a few ways to go forward from here.

1.  Create a record in the table with the same geometry, one for each month.
   1. This gives you duplicate geometry, but each month is its own distinct record. You can then duplicate the layer do what you were doing before.

   2. OBJECTID	Month	Turbidity
      1	January	X
      2	February	Y

2. Create a field for each month, and just store the turbidity data for the field in each month

   1. OBJECTID	January	February	March
      1	X	Y	Z

I'm thinking option 2 is better. You can symbolize each  month layer (which is just the same data wearing a different hat) based on each month's field.

Hope this helps!

[ColeDickison]

This definitely helps! I like both of these work arounds. I will play with it now. Thank you!

[BarryNorthey]

For the most part a "layer" is a representation of a data source such as a geodatabase "feature class". Many "layers" can be created in different maps, projects, etc., from the same underlying feature class. When the underlying feature class is updated such as adding a new field, the attribute table for all layers accessing that feature class will update.  Check the data source for your selection layers and they will likely be pointing to the same data source. You might need to create separate feature classes for each month.