| This study have estimated the PM10 emissions from agricultural sources in northeastern China and developed a county level-based inventory. Seven agriculture-related emission sources were considered, including wind erosion, fertilizer application, harvest, grain handling, land preparation,straw burning and agricultural mechanical exhaust. Using collected emission factor, statistical data,agricultural activity data, we estimated the magnitude and trend of agricultural PM10 emissions from1978 to 2010, and presented temporal-spatial variations for each county in northeastern China.The main results and conclusions were as follows:1).By analyzing provincial-level data from 1978 to 2010, there were significant increasing trend of agricultural PM10 emissions over the past 30 years. The amount of PM10 emissions from field open straw burning has increased from 7.7m tonnes to 28.8m tones. For soil erosion, the PM10 emissions from farmland soils increased from 0.3 million tonnes to 0.4m tones, which was mainly associated with crop planting area. The PM10 emissions from grain handling was ranged from 1.6m tonnes to 4.7m tonnes and the PM10 emissions from fertilizer application was ranged from 0.3m tonnes to 1.9m tonnes. For land preparation, the PM10 emissions increased from 8.7m tonnes to17.3m tonnes. The PM10 emissions from crop harvesting remained stable level of 3m tones. Form1993 to 2010, the amount of PM10 emission from agricultural mechanical exhaust has increased from 0.3m tonnes to 1.3m tonnes. Form 1978 to 2010, the total amount of PM10 emissions from straw burning, wind erosion in farmland, fertilizer application, grain handling, land preparation, and agricultural mechanical exhaust are in a growing trend, except harvest was stabilized.2).In this paper, we presented county-level PM10 emissions from different agricultural processes for standard year 2010. The total amount of PM10 emission in northeastern China form agriculture was 64.5m tonnes. The amount of PM10 emissions followed the order: Heilongjiang(32.69 m tonnes) > Jilin(14.17 m tonnes)> Liaoning(9.65 m tonnes)> four leagues of Inner Mongolia(8.02 m tonnes). Among all emission sources, straw burning was the largest contributor with the share of 54.5%. Grain handling,land preparation and crop harvesting of farmland soil accounted for about 8.2%,26.0%and 6.0%,respectively. The proportion of agricultural machinery emission ã€fertilizer and wind erosion to total emissions were 2.0%, 2.7% and 0.6%, indicating the less significance.3). Temporal variations of different agricultural emissions were analyzed based on 2010-yr inventory. The PM10 emissions from crop harvesting and opening straw combustion have normally peaked in September and October, and also appeared small peak in May. The temporal characteristics of PM10 emissions were in line with the time of harvest and crops straw burning in northeast China. Significant PM10 emissions from fertilizer application always occurred from Aprilto July, which was closely linked to the time the seed fertilizer(in April) and fertilizer(July) in Northeast China. In space, the strong PM10 emissions were distributed in three main plains with intensive agricultural activities and large farmland area in northeastern China, i.e., the Sanjiang plain in northeast of Heilongjiang province, the Songnen plains in the southwest of Heilongjiang and the west of Jilin province, the Liaohe plain in the south of Liaoning province.4).Wed use the error transfer formulas to quantitatively evaluate the 2010 emission inventories for uncertainty analysis. The result showed that the large uncertainty of agricultural machinery emissions PM10 with the value up to 283.0%. The uncertainty of wind erosion emissions PM10 is smaller, 85.6%; The uncertainty of the total emissions is 184.3%. Therefore, the uncertainty of the emissions inventory in this paper was because the activity data and local emission factors were lacked. |
