Scale local emission factors in order to make emission estimates a function of speed.

Source: R/ef_scaled_euro.R

Scale emission factors to account for vehicle speed based on values from the emission factor model by the European Environment Agency (EMEP/EEA). Emission factor estimates are expressed in units 'g/km'.

ef_scaled_euro(
  ef_local,
  speed,
  veh_type,
  euro,
  pollutant,
  fuel = "D",
  tech = "SCR",
  SDC = 19,
  slope = 0,
  load = 0.5,
  fcorr = 1
)

Arguments

ef_local

data.frame or a list containing the emission factors data.frame. Local emission factors, in units 'g/km'.

speed

units. Speed in 'km/h'.

veh_type

character. Bus type, classified as "Ubus Midi <=15 t", "Ubus Std 15 - 18 t", "Ubus Artic >18 t", "Coaches Std <=18 t", or "Coaches Artic >18 t".

euro

character. Euro period of vehicle, classified in "Conventional", "I", "II", "III", "IV", "V", "VI", and "EEV".

pollutant

character. Pollutant: "FC", "CO2", "CO", "NOx", "VOC", "PM10", "EC", "CH4", "NH3", "N2O", "FC" (fuel consumption).

fuel

character. Fuel type, classified in "D" (Diesel), "DHD" (Diesel Hybrid ~ Diesel), "DHE" (Diesel Hybrid ~ Electricity), "CNG" (Compressed Natural Gas), "BD" (Biodiesel). Default is "D".

tech

character. After treatment technology, classified in "SCR" (Selective Catalytic Reduction), "EGR" (Exhaust Gas Recirculation), and "DPF+SCR" (Diesel Particulate Filter + SCR, for Euro VI). Default is "SCR" for "IV" and "V".

SDC

numeric. Average speed of urban driving condition in 'km/h'. Default is 19 km/h, which is the average speed adopted in EMEP/EEA report.

slope

numeric. Slope gradient, categorized in -0.06, -0.04, -0.02, 0.00, 0.02, 0.04 and 0.06. Negative gradients means downhills and positive uphills. Default is 0.0.

load

numeric. Passenger load ratio, classified in 0.0, 0.5 and 1.0. Default is 0.5.

fcorr

numeric. Correction based on fuel composition. The length must be one per each euro standards. Default is 1.0.

Value

list. Emission factors in units 'g/km'.

Details

The scaled emission factor is related to speed by the expression

EF_scaled (V) = EF_local * ( EF(V) / EF(SDC)),

where EF_scaled(V) is the scaled emission factors for each street link, EF_local is the local emission factor, EF(V) and EF(SDC) are the EMEP/EEA emission factor the speed of V and the average urban driving speed 'SDC', respectively.

Please note that the function reads the vector arguments in the same order as informed by the user. For instance, if the pollutant input is c("CO","PM10") input in the local emission factor function, the order needs to be the same for the pollutant in the ef_scaled_euro function.

In the case of vehicle type, which generally changes according to the emission factor source, the input argument in the ef_scaled_euro needs to be consistent with the order adopted in the local emission factor function.

For example, if the vector of local vehicle type is c("BUS_URBAN_D","BUS_MICRO_D"), the related vector for EMEP/EEA model needs to be c("Ubus Std 15 - 18 t","Ubus Midi <=15 t"). The same approach applies for other input arguments. See more in the examples.

See also

Other Emission factor model: ef_brazil_cetesb(), ef_europe_emep(), ef_usa_emfac(), ef_usa_moves(), emi_europe_emep_wear()

Examples

temp_ef_br <- ef_brazil_cetesb(
                    pollutant = c("CO","PM10","CO2","CH4","NOx"),
                    veh_type = c("BUS_URBAN_D","BUS_MICRO_D"),
                    model_year = c(2015,2015),
                    as_list = TRUE
                    )

temp_ef_scaled <- ef_scaled_euro(
                    ef_local = temp_ef_br,
                    speed = units::set_units(1:100,"km/h"),
                    veh_type = c("Ubus Std 15 - 18 t","Ubus Midi <=15 t"),
                    euro = c("IV","IV"),
                    fuel = c("D","D"),
                    tech = c("SCR","SCR"),
                    pollutant = c("CO","PM10","CO2","CH4","NOx")
                    )
#> 'CO2' Emission factor not found for 'SCR' Technology and Euro 'IV'.
#>  The package assumes missing Technology entry. Please check `data(ef_europe_emep_db)` for available data.
#> 'CO2' Emission factor not found for 'SCR' Technology and Euro 'IV'.
#>  The package assumes missing Technology entry. Please check `data(ef_europe_emep_db)` for available data.
#> 'CO2' Emission factor not found for 'SCR' Technology and Euro 'IV'.
#>  The package assumes missing Technology entry. Please check `data(ef_europe_emep_db)` for available data.
#> 'CO2' Emission factor not found for 'SCR' Technology and Euro 'IV'.
#>  The package assumes missing Technology entry. Please check `data(ef_europe_emep_db)` for available data.