HRA v3.12.0 recieving values > max criteria score for multiple stressors

I am using the habitat risk assessment model to assess the risk of two overlapping stressors for a single species. When I run the model with both stressors, the output total risk rasters have some values greater than the maximum criteria score that I specified (3). This is not expected, right?

If I remove one of the stressors from the model, I receive values under the max criteria score. I have also checked all inputs to ensure there are no values greater than 3 in the classified inputs. Log files for both the run with 2 stressors and the test run with one stressor removed are attached. Thanks!

InVEST-natcap.invest.hra-log-2022-11-22–11_28_41.txt (14.0 KB)
InVEST-natcap.invest.hra-log-2022-11-28–09_25_23.txt (12.3 KB)

Welcome to the forums, @kdeforest !

The maximum criteria score that you provide in the user interface is the maximum score of your scoring system, not the maximum score that the model will produce. In our sample data, the rating system goes from 0 to 3, but you could just as easily use a system from 0-42 or any other maximum score, in which case you would provide 42 in the UI as the maximum score.

So, the scores you provide are then used in the risk equation of choice (euclidean or multiplicative) and then summed to get cumulative risk. So if you have a number of high-risk habitats, you can very easily end up with a cumulative risk score that’s greater than the maximum score in your scoring system.

Hope this helps, and let us know if you have any other questions!

Hi James,

Thanks for your reply! This is helpful. However, I am wondering now if something has changed between versions. In a previous version (a few months ago) my colleague received outputs that were between 0-3 with the same data that I am using. Also, in my recent run with two stressors, the output summary statistics table says that the maximum risk value is 1.73, but the max value in the output total risk raster is 3.46.

This sounds like a bug that I think we might have already fixed. Could you try this development build of HRA and see if you’re still getting strange values in the output table?

Please let us know either way. It’s very possible that this a separate issue.


Hi James,

I downloaded and ran the same data/settings with the version you posted and the issue persists. I am attaching the log!
InVEST-Habitat-Risk-Assessment-log-2022-11-28–11_14_52.txt (38.9 KB)

Hi James,

I am wondering if you have any update on this issue? Thanks! I am happy to send additional files if needed.


Sorry for the delay @kdeforest ! I don’t see anything out of the ordinary in the logfile. Could you send me your complete set of HRA inputs so I can try to reproduce it here and see what might be going on? Feel free to attach them to this thread, or else to email them to me at


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