Hi,
I have been analyzing our SLAMM out put data two ways: 1) using the SLAMM output data tables (and converting ha to ac), and 2) using GIS (calculating ac and ha by converting pixel counts in attribute tables based on pixel size). The GIS analysis is necessary for post-processing some information, like which lands are already conserved, or tracking specific changes in SLAMM classes (e.g. how much area converted from RFM to TF).
I've noticed a significant difference in acreages between the two methods. For example, at time 0 there is a difference of 5 acres in my study area (of about 7,000 acres). But looking at total tidal wetland acreage by 2100, one simulation has a difference of 85 acres. I find these differences even when I'm not aggregating classes (i.e. when comparing the acreages of a single class, like RFM).
Have you encountered this before? Do you have any thoughts on what might be causing these differences?
I would like to continue to use both data sets, as the one from SLAMM reports on all the time steps (which would take a long time to do in GIS).
Thanks,
Nava.
I have been analyzing our SLAMM out put data two ways: 1) using the SLAMM output data tables (and converting ha to ac), and 2) using GIS (calculating ac and ha by converting pixel counts in attribute tables based on pixel size). The GIS analysis is necessary for post-processing some information, like which lands are already conserved, or tracking specific changes in SLAMM classes (e.g. how much area converted from RFM to TF).
I've noticed a significant difference in acreages between the two methods. For example, at time 0 there is a difference of 5 acres in my study area (of about 7,000 acres). But looking at total tidal wetland acreage by 2100, one simulation has a difference of 85 acres. I find these differences even when I'm not aggregating classes (i.e. when comparing the acreages of a single class, like RFM).
Have you encountered this before? Do you have any thoughts on what might be causing these differences?
I would like to continue to use both data sets, as the one from SLAMM reports on all the time steps (which would take a long time to do in GIS).
Thanks,
Nava.