Calculation of agricultural non-point source pollution emission in China and its long-term forecast
中国农业面源污染物排放量计算及中长期预测

With the First National Pollution Source Census in 2007, this paper calculates the agricultural non-point source pollution emissions for all 31 provinces in mainland China. Based on the results, the emission situation during 2010 to 2030 for each province is predicted. Some conclusions are drawn as follows. In 2007, the total emission of agricultural non-point source pollution in China is 1057×104 t, within which COD emission is 825.9×104 t, TN 187.2×104 t, TP 21.6×104 t, and NH4+-N about 22.4×104 t. If more stringent pollution control efforts were not implemented, the pollution of agricultural non-point source would further exacerbate before 2020. Under high-emission scenario, COD emission of agricultural non-point source pollution may reach 1466.5×104 t, highlighting the importance of agricultural non-point source pollution. The emission of agricultural non-point source pollution has spatial differentiation and eastern coastal areas contribute larger proportion of the total emission. However, in the future, the spatial distribution of agricultural non-point source pollution emission may tend to be balanced.