SRGDESC: Surrogate Designation, Description and Surrogate profile filename.AGREF and MGREF: Gridding cross-reference files for area and mobile sourcesBELD3_A, BELD3_B, BELD3_TOT: BELD3 land use data filesBGPRO: Biogenic spatial surrogate fileGRIDDESC: Grids and projection informationAll spatial allocation (gridding) inputs need to be consistent. Each file has a header to indicate the grid projection, location, dimensions, and resolution; SMOKE uses these headers to ensure consistency across all inputs. SMOKE also requires that any meteorology data inputs be consistent with these gridded data. Most programs in SMOKE are capable of processing a modeling grid that is a subgrid of the input data (i.e. spatial surrogates, meteorology data).
Several options are available for creating the spatial surrogate and biogenic land use inputs.
The MIMS Spatial Allocator can create surrogates and prepare BELD3 inputs files for any modeling grid.
Several national surrogate data sets are available online at EPA’s Clearinghouse for Inventories and Emissions Factors. These data sets are at 36-, 12-, and 4-km resolutions.
The gridding surrogates and land use data can be prepared using a GIS program.
The directories where the spatial allocation files should be stored are listed in Table 8.3, “Spatial Allocation Input File Locations”. The table also lists the programs that use each input file.
The Surrogate Description file is used to designate the regional location of the surrogate, the surrogate code number, a brief
description of the code number and the Area and Mobile spatial surrogate file in which surrogate profile can be found. This
file is located in SRGPRO_PATH. See Figure 6.4, “Grdmat input and output files”. The format of the SRGDESC file is shown in Table 8.37, “Format for SRGDESC”.
Table 8.37. Format for SRGDESC
| Line | Position | Description |
|---|---|---|
| 1 | A | #GRID |
| B | Grid name | |
| C | X origin in units of the projection | |
| D | Y origin in units of the projection | |
| E | X direction cell length in units of the projection | |
| F | Y direction cell length in units of the projection | |
| G | Number of columns | |
| H | Number of rows | |
| I | Number of boundary cells | |
| J |
Projection types:
|
|
| K | Projection units | |
| L | Projection alpha value | |
| M | Projection beta value | |
| N | Projection gamma value | |
| O | X-direction projection center in units of the projection | |
| P | Y-direction projection center in units of the projection | |
| 2+ | A | Region of surrogate i.e. USA, MEX, or CAN. (ASCII) (not used by SMOKE) |
| B | Surrogate code number (Integer)(required) | |
| C | Surrogate Description (ASCII 80 characters in quotes) (required) | |
| D | Surrogate file name (ASCII 80 characters) (required) located in SRGPRO_PATH |