Coastal Blue Carbon

NatCap Software Support
1

Good morning

I am a MsC Student from Guinea-Bissau at Faculty of Sciences, Lisbon

University.

I am using the Coastal Blue Carbon model to assess the carbon accumulation in

above and below-ground biomass at the mangrove forests in two Parks of my

country.

I ran the Model but the results for carbon emissions seem to be inconsistent.

I am working in the Cacheu (PNTC) and Cantanhez (PNC) Parks, both with

significant mangrove areas.

Land Use Land Cover raster (GDAL-supported) of two parks were used for the

years 2002, 2007, 2010 and 2015, with 25m spatial resolution, made from

supervised classification of Landsat images .

For PNTC we have 35897, 35267, 38634 and 33949 hectares, respectively for

2002, 2007, 2010, and 2015.

For the period 2002-2007we have a decrease in mangrove area of -630ha, for

2007-2010 we have an increase of 3367ha, and for 2010-2015 we have a decrease

of -4685.

For PNC we have 21466, 20636, 23180 and 17909 hectares respectively for the

same years.

For the period 2002-2007we have a decrease in mangrove area of -830ha, for

2007-2010 we have an increase of 2544ha, and for 2010-2015 we have a decrease

of -5271ha.

We used the following input data for Processor:

LULC Lookup table - two classes Mangrove 1 (defined as a Coastal Blue Carbon

habitat ) / no mangrove 0 (defined as no Coastal Blue Carbon habitat)

Carbon pool initial template (MtCO2e/ha) - only Biomass pool was considered:

0.000143 MtCO2e/ha (value obtained from a former study in the country)

Transitions – we considered the following transitions

  1. Mangrove to No mangrove (high impact);

  2. No mangrove to No mangrove (no carbon change);

  3. No mangrove to Mangrove (Accumulation); and

  4. Mangrove to Mangrove (Accumulation)

Carbon pool transient template

Biomass half-life: 15 years (selected from Invest User Guide)

Biomass-high-imp-disturb: 100% biomass lost (selected from Invest User Guide,

but the value inserted was 1 for total biomass lost)

Biomass-yearly-accumulation (MtCO2e/ha/year): 0.0000049 (computed as a

proportion of 3.42% of total biomass, obtained from a published work).

With this input dataset we obtained:

  1. for C accumulation per hectare in the period, in MtCO2e:

2002-2007 – accumulation 0.0000245

2007-2010 - accumulation 0.0000147

2010-2015 - accumulation 0.0000245

(this is just the yearly increase multiplied by the number of years)

  1. for C emission per hectare in the period, in MtCO2e:

2002-2007 – emmision 0.000138531

2007-2010 - emmision 0.0000366

2010-2015 - emmision 0.000176

These results seem to be not correct, because the emission figures are too

high if compared with the obtained for accumulation. For instance, for

2002-2007 we have a little proportion of mangrove areas lost if compared to

the undisturbed area, which continued to accumulate, but the balance remained

negative. Also, for the period 2007-2010, in which the mangrove area

increased, the balance continues negative.

Can you help me in this subject?

Best Regards

Giselle Dias

2

Hi @Gisa, I’m so sorry about the delay responding to your post. If this is still an issue, could you try running this latest development build of InVEST and see if we might have already fixed this issue?

Here’s the build: https://storage.googleapis.com/releases.naturalcapitalproject.org/invest/3.7.0.post908%2Bh28da88fb0820/InVEST_3.7.0.post908%2Bh28da88fb0820_x86_Setup.exe

If that doesn’t solve the issue, could you attach your logfile and your inputs so we can take a look?

Thanks!
James