Wildfire CAC Emission Inventory for 2015

Warren McCormick

Ministry of Environment and Climate Change Strategy

Victoria, BC

2018 Introduction Following in the steps and protocols of the “Wildfire CAC Emission Inventory for 2010” (http://BC air quality ), an emission inventory of Common Air Contaminants (CAC) for 2015 wildfires in BC was compiled. Methodologies were the same as those used in the 2010 report. Common Air Contaminants include total particulate matter (TPM), particulate matter less than 10 microns (PM10) and particulate matter less than 2.5 microns (PM2.5), carbon monoxide (CO), non-methane hydrocarbons (labelled as volatile organic compounds (VOC), sulphur oxides (SOx) and nitrogen oxides (NOx). Strictly speaking, VOC is a sub-set of the group non-methane hydrocarbons. VOC is a list of organic compounds that are chemically active in the atmosphere and non-methane hydrocarbons are all organic compounds except methane.

Background 2015 was a slightly above average year for the number of fires with 1,858 fires reported compared to the 10 year average of 1,844. In terms of area burned, it was significantly above average with about 280,605 ha consumed compared to the 10 year average of 155,000 ha.

There are 399 fires in the Wildfires of Note list, which makes up the list of fires that is used to compile the inventory. The remaining 1,459 fires were small spot-fires that were generally less than 0.01 ha and represented about 1% of the total emissions.

Over two thirds of the area burned in the province was in Prince George forest region with nearly 193,691 ha. Many fires in this region occur in low value timber and sub-arctic shrub land and are allowed to burn without intervention unless they threaten infrastructure. See Figure 1 for a description of forest regions.

Method The procedure was developed in two parts: collection of the wildfire data and use of the CONSUME model and emission factors to produce emission estimates.

Collection of Wildfire Data Information about wildfires in the province is presented on the webpage http://bcwildfire.ca under the subheading of “Current Wildfire Activity”. On the sub-page the viewer may select summary statistics for the year to date list of all Wildfires of Note including the fire name, start date, size and location (latitude and longitude). The location data of each fire was used to look up the Biogeoclimatic Zone in Hectares BC http://www.hectaresbc.org which provides a description of the forest cover at that point. The Biogeoclimatic Zone data selected for this project gives a description of the type of forest cover. Models and Emission Factors The fire and emission model used is the CONSUME model version 3.0 (written by Prichard, S., Ottmar, R., and Anderson, G. of the Fire and Environmental Research Applications Team, Pacific Wildland Fire Sciences Lab, USDA Forest Service, Seattle). The CONSUME model works in conjunction with the Fuel Characteristic Classification System (FCCS), version 2.0 (written by Prichard, S., Sandberg, D., Ottmar, R., Campbell, P.). Over 200 FCCS fuelbeds, representing common fuel types throughout much of North America, are available in the FCCS reference library. Users may select an FCCS fuelbed to represent their specific project or customize a fuelbed to reflect actual site conditions.

When CONSUME is run in the wildfire mode, the user identifies the FCCS fuelbed that best represents the forest cover description provided by HectaresBC and supplies the area burned in order to estimate emissions.

CONSUME neither estimates sulphur oxides nor nitrogen oxides emissions. Sulphur oxide emissions do vary somewhat with the soil characteristics. Nitrogen oxide emissions are more a function of the process rather than the fuel, with emissions being a function of the combustion temperature. Emission estimates for sulphur oxides and nitrogen oxides will use the previous emissions factor developed by Environment Canada in 2006, as shown in Table 1:

Table 1: Emission Factors for SOx and NOx

Emission Factors (kg/ha)

SOx NOx 0.865 34.6 Note: Taken from Environmental Canada Emissions and Projections Working Group 2006 Emissions Inventory Guidebook Figure 1 – Map of Forest Regions

Provincial Results

Table 1 shows the provincial total for common air contaminants for the 399 Wildfires of Note in 2015; Figure 2 shows this result in graph form.

Table 1: 2015 Province Emission Inventory Estimates (tonnes)

TPM PM10 PM2.5 CO NMHC/VOC SOx NOx 444,888 316,942 295,801 3,182,307 131,997 245 9,805 Figure 2: 2015 Province Wildfire Emissions Estimate

2015 Wildfire Emissions (tonnes) SOx, 245 NOx, 9,805 VOC, 131,997 PM2.5, 295,801

CO, 3,182,307

Inventory Breakdown by Forest Regions

Table 2 shows the inventory of CACs and area burned by forest regions. Figure 3 shows the PM2.5 inventory by forest region. Table 3 shows the number of fires, average size and % of total area burned by forest region.

Table 2: 2015 CACs (tonnes) % of Total Area Burned by Forest Regions

Region % area TPM PM10 PM2.5 CO VOC SOx NOx Cariboo 3 23,749 17,167 15,974 177,914 8,193 9 341 PrGeorge 68 284,858 200,647 187,084 1,818,418 83,871 168 6,705 Kamloops 4 25,669 18,570 17,319 204,819 8,433 10 399 Southeast 5 33,974 24,851 23,228 286,155 10,884 12 492 Northwest 10 34,867 24,091 22,420 227,499 11,270 25 1,007 Coast 9 41,770 31,616 29,776 467,502 9,345 22 861 Figure 3: 2015 PM2.5 Emissions by Forest Region

2015 Wildfire PM2.5 Emissions Coast Cariboo 10% 5%

Northwest 8%

Southeast 8%

Kamloops 6%

Prince George 63%

Provincial Total = 295,801 tonnes

Table 3: 2015 Number of Fires by Forest Region

Region Number Average % of Total Area Area Cariboo 43 229 3 PrGeorge 113 1,714 68 Kamloops 79 146 4 Southeast 108 132 5 Northwest 23 1,264 10 Coast 33 754 9

Of note is the fact that the % of PM2.5 emissions by forest region does not match the % of area burned by forest region due to the use of different emission factors for various forest regions due to the different types of trees found in the bioregions of the province.