problem using CBC model (no carbon emissions)

Hi everyone,
I am using Coastal Blue Carbon model to quantify the carbon stored by
Posidonia oceanica (an endemic marine plant of the Mediterranean sea)
meadows and the carbon lost resulting from disturbance (anchoring).
I reproduced the impact on different type of P.oceanica meadows (LULCs)
using global and local values within the transition matrix and carbon pools
and storage tables (attached to this post).
The model calculates the carbon accumulation but does not produce emissions.
I am grateful if anyone can help me to resolve the problem.
Thank you in advance
Simone
aligned_lulc_0_2.tif (11.4 KB) carbon_pool_initial_template.csv (311 Bytes) carbon_pool_transient_template.csv (668 Bytes) lulc_lookup.csv (235 Bytes) transitions.csv (705 Bytes)

Hi Simone, thanks for attaching your inputs!

While the Coastal Blue Carbon model is capable of calculating emissions, the emissions calculations are determined by disturbances at specific timesteps … but given the inputs you have here, only the information for the current timestep is provided. The model can only calculate storage for the current timestep, so that’s what it’s doing.

If you’re looking for emissions as well, you’ll need to either:

  • Prepare additional landcover rasters (one per disturbance year) and then provide these and the years of the disturbance into the CBC model input window.
  • Provide an analysis year

Either of these options will allow the model to do the time-based emissions calculations that you’re looking for.

Thanks for your patience on this and I’m so sorry about the delay.
James

Hi James,
Thank you for answering me back! We tried the example data allocated inside the dataset for the 3.5.0 InVEST version (that you can find attached to this email). We managed to have the emissions outputs, introducing into the model the future disturbance landcover rasters, their relative years, and setting the analysis year.

Now that we have clear that we need future landcover rasters, how can we generate them? Is it possible to do so with an InVEST helper tool, or how can we do it?

SimoneCoastalBlueCarbon_3.5.0.zip (78.9 KB)

Hi Simone,

Glad to hear you were able to get the emissions outputs using the sample data!

InVEST does have a scenario generator (http://releases.naturalcapitalproject.org/invest-userguide/latest/scenario_gen_proximity.html) that focuses on the expansion of one landcover into other neighboring landcover codes in your landscape (as you might expect would happen with agricultural expansion).

With coastal blue carbon, you might find the examples in the Freeport, TX use case described in the Coastal Blue Carbon chapter of the user’s guide useful, particularly how SLAMM was used under various sea level rise scenarios. (http://releases.naturalcapitalproject.org/invest-userguide/latest/coastal_blue_carbon.html#example-use-case)

Otherwise, I suspect that the tool most useful to you will depend greatly on what sorts of future scenarios and/or events you’d like to model. Do you have an idea of this? If so, maybe we can point you towards some more specific tools?

Hi Simone -

James gave some good pointers, and I’ll also chime in about creating scenarios for Blue Carbon. The first question is what kind of scenarios are you considering? That will determine how you go about making them. Some examples:

If you want to look at different disturbance levels, then you can change values in the transition tables to show low/med/high levels of disturbance, without needing to change the LULC raster. To only change species, or species carbon attributes, you can also just update the input tables.

If you want to change something like the area of the meadow, and know the new extent, you can create a polygon with the new extent and use it to update the LULC.

If you have climate change data showing how the meadows might be affected, you can incorporate that into the LULC.

Just a few ideas…

~Stacie

1 Like

Hi Stacie and James,
Firstly, we tried using just one LULC raster (the baseline raster) and changing values in the transition table in order to analyse the disturb due to boat anchoring on P.oceanica meadows. We also updated the input tables with even more accurate data. However, the model didn’t output any emissions (See Sim1.zip).
After that, we created through QGIS a new LULC raster from a disturb map obtained from HR satellite data. It has been made to “force” transitions from a blue carbon habitat to a non-carbon habitat. Even in this case, the model didn’t generate any emissions (See Sim2.zip).

So, we need to generate future land cover rasters describing how the meadow’s extension may change with specific anchoring rates or events. Could we use the Scenario Generator to do so or we can just change values in the transition tables as Stacie suggested?

Thank you both for your help!

Sim1.zip (99.5 KB) Sim2.zip (350.0 KB)