Symbology forMultiple Attributes in ArcMap?

Question

I need some help to map landslide proximity to urban areas and their size on ArcMap 10.5.1. I am unsuccessfully trying to use symbology by multiple attributes. The data is point data but within the attribute table I have information about landslide proximity to urban areas and their size.

I would like a different colour for the points according to their proximity to urban areas - eg for those less that 1km distance, those more than 1km but less than 2km etc. I would also like the size to be linked to the size of the landslide.

Could someone advise me how to create the ranges for colour section - I can only seem to colour every point arbitrarily.

Unlike for symbology by quantities there seems to be no way to put in a range for the value (see fig). How does one do this?

I wish for a range such as this to be adopted but then the symbols to also be graduated in size according to a field called shape area.

I am unable to change the size and keep different colours for the landslides according to their proximity (as I did above in fig2).

Answer 1

I think the issue here is that the symbolising by Multiple Attributes option is looking at unique combinations of attributes from the value fields and using fields of type Double (or similar) gives it too many combinations and it won't do a classification on-the-fly. You may need to pre-process the data first by adding classification fields for the proximity and landslide size.

I created some random points containing random double values in two fields. I then reclassified the two fields using a Python code block in Field Calculator.

Following the instructions in this link, I was able to produce these results.

Answer 2

Categorise your distance_km in another field, preferable a SHORT one (say, 0-1000 is 1, 1000-2000 is 2, and so on) and then use the Shape_AREA field in either Color Ramp... or the Symbol Size... section. Unfortunately, the main dialog shown in the Multiple Attributes expects you a categorised field where it can list the unique values, as its subheading implies Quantities by category.

Basically you need to use the categorised distance as your category here (coming from a new field) and to decide the colour scheme or size which should be quantitative/numeric. Again, the second part where you decide colour or size lets you to categorise your data based on your preference (like in "Graduated colors" symbology option).