Rice Straw Burning-85
 

 

 

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Project Leader

Don Schukraft, Nowcasting

Les Fife, Fife Environmental

 

Objectives

The objectives of the Agricultural Burning Test Program are to protect air quality in the Sacramento Valley and to allow agricultural burning on a daily basis. Also to make program decisions based on valleywide and local problems to ensure program success through continued refinements, good communications, continued cooperation and compliance with program procedures.

The three components of the program receiving Rice Research Board funding are 1) Nowcasting, the gathering, analysis and dissemination of atmospheric data useful for determining conditions favorable for burning rice straw; 2) Control Council, the decision-making and allocation system for rice straw burning; and 3) Agricultural Burning Test Program, which provides program advice and monitors results.

The data elements of the program are 1) air quality readings, as measured by the coefficients of haze, airport visibilities, and complaints; 2) meteorological observations, which include wind speeds and directions, temperatures, humidities, cloud cover, and inversions; and 3) acreage information, i.e. acres to be burned and daily burned acreages by county.

Meteorological Conditions

The 1985 fall burning period had numerous days with north winds, below normal rainfall, generally stable atmospheric conditions, and the highest average stability in temperature between the surface and 3,000 feet in the last six years. This unusually high stability caused the mixing heights in the valley to be generally lower and led to the potential for higher pollution concentrations.

Good management decisions within the burn program allowed for a maximum number of acres to be burned while minimizing high pollution concentrations created by the poor meteorological conditions. Average wind speeds were similar to previous years. Measurable rainfall occurred in the valley on 11 days during the 69-day fall burning period.

Summary of Results

The fall burning period began September 16 and ended November 23, the longest (69 days) and the most meteorologically adverse burning period in the last six years. Because of cool summer temperatures, rice harvest was late and no significant amounts of straw were burned until early October. The total amount of straw burned was 275,480 acres, the greatest amount in the past six years.

Results of the 1985 fall burning program were very good considering the stable meteorological conditions, although air quality readings as measured by the coefficients of haze and smoke reported at valley airports were higher than last year's readings.

Complaints made to the Air Resources Board were lower than in 1984 but higher than in the three previous years. A total of 153 complaints were made to the counties and the Air Resources Board. Most of these complaints were from Sacramento, Butte, Yolo and Solano counties. There were no recurrences of last year's problem of dense smoke intrusion into urban areas, however. Each county handled placement of fires in its burning management zones to minimize air pollution.

Acres burned ranged from 46 on October 21, to 15,917 on November 9. Only one day, November 3, was declared a no-burn day because of very poor atmospheric conditions. There were five days when burning exceeded 10,000 acres.

A new feature of the program in 1985 was hourly weather observations from the automatic meteorological observing stations and airports through Weather Network, a computer data base. This additional data allowed a better placement of fires during the day and kept each county informed of changing wind conditions, resulting in better air quality.

The coordination of all parties concerned, including the central computer operator, Nowcasting, Air Resources Board, and county personnel provided a very successful fall burn program as evidenced by the increase in acres burned and reduction in complaints regarding air quality.

 

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