EMISSION INVENTORY SOURCE CATEGORY

METHOD SUMMARY

This category includes 1993 estimates of fugitive dust particulate matter entrained by vehicular travel on unpaved farm roads. These are typically private roads that are used to access agricultural lands to perform growing and harvest operations.

ACTIVITY DATA SOURCE:  Agricultural unpaved road activity data is based on the number of acres of crops harvested in each county. These data are based on county agricultural commissioner report data compiled by the California Department of Food and Agriculture. Based on an estimate by a member of the former Fresno County APCD in 1976, it is assumed that the unpaved road travel rates are 175 vehicle miles traveled per 40 acres of land (175 VMT/40 acres). These values are used to compute the farm road VMT for each county.

EMISSION FACTOR SOURCE:  The unpaved road dust emission factor was computed by averaging unpaved road dust emission measurements performed by the University of California, Davis, and the Desert Research Institute. The emissions measurements were performed in the San Joaquin Valley at different sites. The same emission factor is used for agricultural and non-agricultural unpaved roads.

TEMPORAL DATA:  Daily activity on agricultural unpaved roads occurs primarily during daylight hours. Activity is assumed to be the same each day of the week. The monthly activity profile increases during the months that there is higher agricultural activity and the roads are dry (Spring and Fall).

DATE OF THE LAST UPDATE:  August 1997

GROWTH PARAMETER:  Growth based on agricultural crop acreage or agricultural production. Set to zero for many regions.

STATEWIDE EMISSIONS SUMMARY (1993 - ANNUAL AVERAGE TONS/DAY)

CES No.	TOG	CO	NOX	SOX	PM
47431	0.00	0.00	0.00	0.00	203.1

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This page last revised on November 12, 1997.

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