Hi,
My name is Isabella Smith, and I am trying to get results from the Coastal Blue Carbon InVEST model for my honors capstone research paper on kelp in MA; however, I have encountered an issue with the output results from my data. I have run the model successfully; however, when I try to visualize the map which i have done in ArcGIS outputs to show carbon stocks, accumulation, net present value, etc., they all seem to show 0’s as the high and low values instead of the high as 1 for presence and low as 0 for absence along with the no data value being 0, as seen in the baseline maps and represented in the data tables. I’m not sure if it’s supposed to be the same as the baseline maps and/or should display the resulting data values, which should be greater than 0 from the input data, but there appears to be no data at all. I’m also unsure if it’s a modeling issue or a visualization issue, either.
Here is the input data, including the price of carbon as $30, the interest rate as 7%, and the discount rate as 1.5%, the resulting log text, and one of the results it produced. Any help is greatly appreciated!
InVEST-coastal_blue_carbon-log-2026-04-16–20_28_04.txt (232.8 KB)
all_kelp_current.tif (22.8 KB)
all_kelp_pres_abs_ssp370_2090.tif (18.5 KB)
snapshots.csv (92 Bytes)
biophysical.csv (466 Bytes)
transitions.csv (111 Bytes)
net-present-value-at-2090.tif (6.8 KB)
Hi Isabella,
Thanks for posting about this and providing your inputs! Given your descriptions of what you expect to happen, I think your data might not quite be formatted in the way you probably want them to be.
Given your inputs, the Net Present Value raster’s values are calculated from the total carbon accumulated at 2090. If you load up the raster carbon-accumulation-between-2025-and-2090.tif, you’ll see that there is no carbon accumulation at all between those years, indicated by all pixel values being 0. So why is that? Well, I see that your input LULC rasters all have pixel values of 0 or 1, which have carbon pool values of 0 in your biophysical table. So even though you have pixels in 2025 transitioning from pixel values of 1 to 0 in the year 2090, there’s no change in carbon. Because there’s no change in carbon, there’s no net present value of the change in carbon to calculate.
To correct this, I think you’ll just need to update your LULC rasters to make sure that the regions you want to represent as kelp and non-kelp are correctly represented and I’d expect the model to then produce NPV values that make more sense.
Hope this helps, and let me know if you have any further questions!
James
Hi jdouglass,
Oh, okay, I see what you mean.
So the original/baseline raster maps are or should be represented as 0 for absence/non-kelp and 1 for presence/kelp, but you’re saying it seems to be reflecting the lucodes 0 for non-data and 1 for non-kelp values which are 0s in the biophysical table, instead of the lucode 2 for kelp values of carbon pools in the same table and should be represented that way instead, if i understood correctly? If so, should I then change the biophysical table? Or your suggesting the maps overall specifically should be represented differently?
Thank you so much for the response!
Yes, since your “No-Data” class is functionally the same as non-kelp, the easiest thing to do would be to have only 2 classes:
lucode=0 as your Non-kelp class, with all values of 0 in your biophysical tablelucode=1 as your Kelp class, with all the appropriate biophysical carbon pool values.
Once you make these modifications to your landcover table, then you should at least see some interesting spatial variation in the carbon change.
Oh okay! I will try that and see if it works. Thank you!