topic Classifying a raster based on a certain percentage in ArcMap Questions

Classifying a raster based on a certain percentage

Arthur_Morgan — Fri, 26 Mar 2021 00:25:52 GMT

How can I classify a raster such that top 1% of the areas with the highest positive and highest negative values are highlighted?

DanPatterson — Fri, 26 Mar 2021 02:18:42 GMT

Zonal Statistics function—ArcGIS Pro | Documentation at least in ArcGIS Pro, so check arcmap documentation.

percentile is on the list, it may be a 2 pass operation, but you can combine the results

JayantaPoddar — Fri, 26 Mar 2021 10:46:04 GMT

For symbolizing the raster into highest/lowest 1% values, you could follow these steps:

1. Under Symbology > Classified > Press Classify button.

Change the classification method to "Quantile". Change classes to 100.

Under Break Values, note the value of 1st break (28 in my example) and 99th break (225 in my example).

2. Then, click "Exclusion..." button. And define the 1st and 99th break value with a hyphen (e.g. 28-225 or 28.01-224.99).

Now change the Classification method to "Equal Interval" and classes to 2. Click OK

3. Choose appropriate color ramp and labels.