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This package provides some methods to create emissions (with a focus on vehicular emissions) for use in numeric air quality models such as WRF-Chem.

Installation

System dependencies

EmissV import functions from ncdf4 for reading model information, raster and sf to process grinded/geographic information and units. These packages need some aditional libraries:

To Windows

No additional steps for windows installation.

Detailed instructions can be found at netcdf, libudunits2-dev and sf developers page.

Package installation

To install the CRAN version (0.664.9):

To install the development version (0.665.0.1):

Using EmissV

In EmissV the vehicular emissions are estimated by a top-down approach, i.e. the emissions are calculated using the statistical description of the fleet at avaliable level (National, Estadual, City, etc).The following steps show an example workflow for calculating vehicular emissions, these emissions are initially temporally and spatially disaggregated, and then distributed spatially and temporally.

I. Total: emission of pollutants is estimated from the fleet, use and emission factors and for the interest area (cities, states, countries, etc).

II. Spatial distribution: The package has functions to read information from tables, georeferenced images (tiff), shapefiles (sh), OpenStreet maps (osm), global inventories in NetCDF format (nc) to calculate point, line and area sources.

Figure 1 - Emissions of CO using nocturnal lights.

III. Emission calculation: calculate the final emission from all different sources and converts to model units and resolution.

CO_emissions <- emission(TOTAL,"CO",list(SP = Sao_Paulo, MG = Minas_Gerais),grid,mm=28, plot = T)
# calculating emissions for CO using molar mass = 28 ...

Figure 2 - CO emissions ready for use in air quality model.

IV. Temporal distribution: the package has a set of hourly profiles that represent the mean activity for each day of the week calculated from traffic counts of toll stations located in São Paulo city.

data(perfil)
names(perfil)

The package has additional functions for read netcdf data, create line and point sources (with plume rise) and to estimate the total emissions of of volatile organic compounds from exhaust (through the exhaust pipe), liquid (carter and evaporative) and vapor (fuel transfer operations).

Functions:

  • read: read global inventories in netcdf format
  • vehicles: tool to set-up vehicle data.table
  • emissionFactor: tool to set-up emission factors data.table
  • gridInfo: read grid information from a NetCDF file
  • pointSource: emissions from point sources
  • plumeRise: calculate plume rise
  • rasterSource: distribution of emissions by a georeferenced image
  • lineSource: distribution of emissions by line vectors
  • streetDist: distribution by OpenStreetnMap street (in progress)
  • areaSource: distribution of emissions by region
  • totalEmission: total emissions
  • emission: Emissions to atmospheric models
  • speciation: Speciation of emissions in different compounds

Sample datasets:

  • Species: species mapping tables
  • Perfil: vehicle counting profile for vehicular activity
  • Sample of an image of persistent lights of the Defense Meteorological Satellite Program (DMSP)
  • CETESB 2015 emission factors as emissionFactor(example=T)
  • DETRAN 2016 data and SP vahicle distribution as vehicles(example=T)
  • Shapefiles for Brazil states

Contributing

Bug reports, suggestions, and code contributions are all welcome. Please see CONTRIBUTING.md for details. Note that this project adopt the Contributor Code of Conduct and by participating in this project you agree to abide by its terms.

License

EmissV is published under the terms of the MIT License. Copyright (c) 2018 Daniel Schuch.