Questions about results from Habitat Quality in different versions of InVEST

NatCap Software Support
1

Hi~
I used to run the habitat quality in InVEST 3.4.4 smoothly and just downloaded the InVEST 3.7.0. Using the same data inputs, I ran the habitat quality in InVEST 3.7.0 to test. Comparing with previous result from InVEST 3.4.4, the result of habitat quality estimated by InVEST 3.7.0 was unreasonable and different. I also downloaded the InVEST 3.6.0 and run this vesion of software again using the same data.This time the software failed to process the no value data in the land use data and asked me to add the corresponding information in the sensitivity table, which was hard as the value simply representing the no value part of land use data should not included in the table. I noticed that the algorithm of habitat quality in the users’ guide did not changed with the updates InVEST software. So I wonder if you can help me with this problem that I encountered in different versions of InVEST. Thank you and looking forward to your reply.

2

Hi @Char, it’s true that the model’s math hasn’t changed, but there were some behind-the-scenes changes that might explain some of the differences you’re seeing. We have fixed a number of these issues since the 3.7.0 release, so could you try this development build and see if the issues with the outputs persists?

Here’s the download link: https://storage.googleapis.com/releases.naturalcapitalproject.org/invest/3.7.0.post478%2Bhb364bc60ac3d/InVEST_3.7.0.post478%2Bhb364bc60ac3d_x86_Setup.exe

Let us know how this goes!

1 Like
3

Hi~
Thank you very much for your prompt reply and kindness. I tried the version of software that you had given in this website. It went well and the result of habitat quality from this version was reasonable and acceptable in terms of the general pattern, though it differed from the result of habitat quality of InVEST 3.4.4 to a certain degree. The differences were noticeable especially on the edge of the habitat quality map.

4

Hmm … all of the changes in the Habitat Quality model made between 3.4.4 and the development version I sent you were very minor and should not have affected the outputs much if at all. It is possible that we fixed some bugs or perhaps did some other maintenance that might have affected the outputs.

Could you tell us a bit more about the degree to which the outputs were different? Alternatively, could you show us what the pattern of the differences looks like? Even sending the outputs you’re concerned about could be helpful.

Thanks!
James

5

Hi~
The average value of habitat quality from the development version was lower than that from the InVEST 3.4.4, which may be caused by the lower values on the edge of habitat quality map from the development version. I calculated the difference between the two results, and all the negative values almost surrounded my study area and were on the edge of the map.

6

Hmm, is the difference between the values of the two versions large enough to be suspicious given what you would expect on your landscape?

We regularly enhance and and fix all of the InVEST models, so it’s possible that changes in the numerical values might be explained by some bugfixes. Of course it’s also possible that something else, undesireable is happening. If the latter is the case, we’ll want to look into it more :slight_smile: