HRA - Exponential decay buffer distance

Software Support
1

Hello,

I am running an issue on the HRA model (InVEST version 3.17.0): for exponential decay, the risk outputs do not change by changing the decay buffer distance of a particular stressor. I’ve seen that this was an issue for the Habitat Quality model. Does it also occur in the HRA?

Thanks,

Glo

InVEST-habitat_risk_assessment-log-2026-03-18–12_02_47.txt (68.6 KB)

InVEST-habitat_risk_assessment-log-2026-03-18–12_01_56.txt (68.3 KB)

2

Hi @Glomo93, welcome to the forum! In your model inputs, are you providing spatially explicit layers (i.e., rasters or vectors) for any criteria rating scores? If so, it’s possible that your spatial layers do not include rating values in the buffer area, in which case, the model is ignoring the buffer area (effectively making the decay buffer distance 0, regardless of the buffer distance you specify). For a more detailed explanation, see this note in the User Guide: Habitat Risk Assessment: Using Spatially Explicit Criteria. Please check your inputs and make sure any rating score rasters/vectors contain values over the entire area of influence, including buffer zones. If that doesn’t solve the problem, let us know!

3

Hi @edavis, thanks so much for the reply and sorry for the delay (I did not have the chance to run the model in the last month until now).

Indeed, I did not have the rating outside of the buffer zone, and I fix this. However, the problem still persists. The interesting thing is that the linear decay works fine (even before), it’s only the exponential that gives me problems.

I tried to run simulations without any spatially-explicit intensity rating, changing considerably the buffer distances, and still, the exponential decay doesn’t show any effect of the buffer distance.

I attach the latest log files.

InVEST-habitat_risk_assessment-log-2026-05-12–16_45_09.txt (111.8 KB)

InVEST-habitat_risk_assessment-log-2026-05-12–16_43_07.txt (111.6 KB)