The factors are not assigned for grids over water in surrogate 350

Spatial Allocator
1

Hi all,

I am generating the GHG2020 emission using the surrogates based on the 2020platform and found there are no emissions over water, such as the Great Lakes. In the surrogate 350 (NLCD water), the fractions for grids over water are not assigned, while they are assigned in 2017 and 2019 platforms. Then I tried the us12k_516x444 surrogate and it shows emissions over water.

Do you have any idea?

Here are the settings:
2020:
#SURROGATE REGION = USA
#SURROGATE CODE = 350
#SURROGATE NAME = NLCD Water
#DATA SHAPEFILE = cb_2020_us_county_500k
#DATA ATTRIBUTE = geoid
#WEIGHT SHAPEFILE = nlcd_2019_land_cover_l48_20210604_500m_ll
#WEIGHT ATTRIBUTE = NONE
#WEIGHT FUNCTION =
#FILTER FUNCTION = GRIDCODE=11

2017:
#SURROGATE REGION = USA
#SURROGATE CODE = 350
#SURROGATE NAME = NLCD Water
#DATA SHAPEFILE = NTAD_2017_County_Pol
#DATA ATTRIBUTE = CTFIPS
#WEIGHT SHAPEFILE = CONUS_AK_NLCD_2011_500m_WGS
#WEIGHT ATTRIBUTE = NONE
#WEIGHT FUNCTION =
#FILTER FUNCTION = gridcode=11

image
image1732×586 522 KB

Thank you,
Siqi

2

When you say there are no emissions over water, do you specifically mean the Great Lakes?

The water surrogate is primarily used for pleasure craft and there is little pleasure craft actiity in the Great Lakes, so we excluded those areas from the surrogates we developed for the 2020 platform.

Commercial marine vessels are developed separately and do not use spatial surrogates and are located over water.

3

Hi Alison,

There are no emissions in bays and sounds in eastern US, either, such as Chesapeake Bay, Delaware Bay, and Pamlico Sound.

The 12 km surrogates (which use the same input shapefiles) contains the emissions from water:

image
image804×612 26.2 KB

Thanks,
Siqi