(In)tervention (M)odel for (A)ir (P)ollution
InMAP is a multi-scale emissions-to-health impact model for fine particulate matter (PM2.5) that mechanistically evaluates air quality and health benefits of perturbations to baseline emissions. The main simplification of InMAP compared to a comprehensive chemical transport model is that it does so on an annual-average basis rather than the highly time-resolved performance of a full CTM. The model incorporates annual-average parameters (e.g. transport, deposition, and reaction rates) from the WRF/Chem chemical transport model. Grid-cell size varies as shown in Figure 1, ranging from smaller grid cells in urban areas to larger grid cells in rural areas; any grid cell above a specified population threshold is subdivided until no grid larger than 1 km has >10,000 people. This variable resolution grid is used to simulate population exposures to PM2.5 with high spatial resolution while minimizing computational expense.
Figure 1: InMAP spatial discretization of the model domain into variable resolution grid cells. Left panel: full domain; right panel: a small section of the domain centered on the city of Los Angeles.
Go to releases to download the most recent release for your type of computer. For Mac systems, download the file with "darwin" in the name. You will need both the executable program and the input data ("inmapData_xxx.zip"). All of the versions of the program are labeled "amd64" to denote that they are for 64-bit processors (i.e., all relatively recent notebook and desktop computers). It doesn't matter whether your computer processor is made by AMD or another brand, it should work either way.
Compiling from source
You can also compile InMAP from its source code. It should work on most types of computers. Refer here for a list of theoretically supported systems. Instructions follow:
Install the Go compiler. Make sure you install the correct version (32 or 64 bit) for your system. Also make sure to set the
$GOPATHenvironment variable to a different directory than the
$GOROOTenvironment variable (it can also not be a subdirectory of
$GOROOT). It may be useful to go through one of the tutorials to make sure the compiler is correctly installed.
Make sure your
$PATHenvironment variable includes the directories
$GOPATH/bin. On Linux or Macintosh systems, this can be done using the command
export PATH=$PATH:$GOROOT/bin:$GOPATH/bin. On Windows systems, you can follow these directions.
Install the git and mercurial version control programs, if they are not already installed. If you are using a shared system or cluster, you may just need to load them with the commands
module load gitand
module load hg.
Download and install the main program:
go get github.com/spatialmodel/inmap/inmap
The Go language has an automatic system for finding and installing library dependencies; you may want to refer here to understand how it works.
Running the InMAP example case
From the testdata directory, download all of the files that match the pattern "inmap_*.gob" or "testEmis.*", where * is a wildcard that can match any set of characters. If you have followed the instructions in the "Compiling from source" section above you will already have downloaded these files. Next, download the file configExample.json and the InMAP executable program in the same directory. Next, open the file "configExample.json" with a text editor and delete the text "../testdata/" anywhere you see it. Finally, open a command prompt window, navigate to the directory where you saved the aforementioned files, and run the command
inmap1.1.0linux-amd64 -config=configExample.json on Linux systems,
inmap1.1.0darwin-amd64 -config=configExample.json on Mac systems, or
inmap1.1.0windows-amd64.exe -config=configExample.json on Windows systems to run the program. The program should run without any error messages and create a file called "output_0.shp" (along with supporting files like "output_0.dbf") which can be viewed with any program that can view shapefiles. Refer to the next section for additional details.
Make sure that you have downloaded the general input files (
InMAPData). It is important to download the version of the input files that match the version of InMAP you are using.
Create an emissions scenario. Emissions files should be in shapefile format where the attribute columns correspond to the names of emitted pollutants. Refer here (the
EmisNamesvariable) for acceptable pollutant names. Emissions should be in units of short tons per year. The model can handle multiple input emissions files, and emissions can be either elevated or ground level. Files with elevated emissions need to have attribute columns labeled "height", "diam", "temp", and "velocity" containing stack information in units of m, m, K, and m/s, respectively.
Emissions will be allocated from the geometries in the shape file to the InMAP computational grid, but currently the mapping projection of the shapefile must be the same as the projection InMAP uses. In ESRI format, this projection is:
PROJCS["Lambert_Conformal_Conic_2SP",GEOGCS["GCS_unnamed ellipse", DATUM["D_unknown",SPHEROID["Unknown",6370997,0]],PRIMEM["Greenwich",0], UNIT["Degree",0.017453292519943295]],PROJECTION["Lambert_Conformal_Conic_2SP"], PARAMETER["standard_parallel_1",33],PARAMETER["standard_parallel_2",45], PARAMETER["latitude_of_origin",40],PARAMETER["central_meridian",-97], PARAMETER["false_easting",0],PARAMETER["false_northing",0],UNIT["Meter",1]]
Make a copy of the configuration file template and edit it so that the
EmissionsShapefilesvariables point to the locations where you downloaded the general input and emissions files to, and so the
OutputTemplatevariable points to the desired location for the output files. The wildcard
[layer]is a place holder for the vertical layer number. (Input and output data are separated into individual files by model layer). Refer directly to the source code (here) for information about other configuration options.
Run the program:
for Mac or Linux systems, and inmap.exe -config=/path/to/configfile.json for windows systems. If you are using the precompiled version of the program downloaded from the website, you will need type "inmap1.1.0windows-amd64.exe" instead of "inmap.exe" etc. as described above. While the program is running, you can open a web browser and navigate to
localhost:8080to view status and diagnostic information.
View the program output. The output files are in shapefile format which can be viewed in most GIS programs. One free GIS program is QGIS. Output from each model layer is put into a separate file. Layer 0 is the one closest to the ground and will probably be of the most interest. By default, the InMAP only outputs results from layer zero, but this can be changed using the configuration file. The output shapefiles have a number of attribute columns. They include:
- Pollutant concentrations in units of μg m-3:
- VOC (
- NOx (
- NH3 (
- SOx (
- Total PM2.5 (
TotalPM2_5; The sum of all PM2.5 components)
- Particulate sulfate (
- Particulate nitrate (
- Particulate ammonium (
- Secondary organic aerosol (
- VOC (
- Populations of different demographic subgroups in units of people per square meter. The included populations may vary but in the default dataset as of this writing the groups included are:
- total population (
- people identifying as black (
Black), asian (
Asian), latino (
Latino), native american or american indian (
Native), non-latino white (
WhiteNoLat) and everyone else (
- People living below the poverty time (
Poverty) and people living at more than twice the poverty line (
- total population (
- Numbers of deaths attributable to PM2.5 in each of the populations in units of deaths/year. Attribute names in shapfiles are limited to 11 characters, so, for example, deaths in the
TotalPoppopulation would be labeled
TotalPop de, deaths in the
Blackpopulation would be labeled
Black death, and—interestingly—deaths in the
WhiteNoLatpopulation would be labeled
- Baseline mortality rate in units of deaths per year per 100,000 people, which can be used for performing alternative health impact calculations.
- Pollutant concentrations in units of μg m-3:
The InMAP package is split into an executable program and an application programming interface (API). The documentation here shows the functions available in the API and how they work.