Discrepancies in creating CA surrogates

Spatial Allocator
1

Hello everyone,

I created Canadian surrogates using pg_srgtools (Spatial-AllocatorV4.4). However, the outputs differ from those in the NEI2022 platform.

The settings are from: Surrogate_specifications_2022_platform_US_Can_Mex.xlsx (82.4 KB)

One output surrogate: CA_212_NOFILL_sma.txt (1.8 MB)

The surrogate from the platform: CA_212_NOFILL.txt (1.7 MB)

Here is the diffsurg log: diffsurr_CA_212.txt (33.3 KB)

In the regions with big discrepancies (e.g., 160000), the denominators in CA_212_NOFILL.txt are much larger than the sum of the numerators; therefore, the surrogate value is 0. But the values in CA_212_NOFILL_sma.txt are not 0.

I also tried it with srgtools, the results are consistent with those from the NEI platform.

I would be grateful if someone could help me solve this problem. Thanks.

Siqi

2

EPA now uses surrogates generated from the SurrogateToolsDB and not the Spatial Allocator.

The Spatial Allocator release has not been updated in several years.

As you found there could be some differences in the handling of some data by the two tools.

We do not plan to look into this further, but someone in the community may have some suggestions.

3

Hi,

I used the scripts from the SurrogateToolsDB, and the results look fine now.

Thanks,

Siqi