Estimation of Non-Point Source Pollution Load of the Livestock and Poultry Breeding in Sichuan Province, China

The study was to estimate the livestock and poultry breeding (LPB) non-point source pollution load in Sichuan province and provide support for control of LPB non-point source pollution. In the study, an improved export coefficient method was proposed to estimate LPB non-point source pollution loads from the stages of generation, discharge and export. Based on the established model, total nitrogen (TN), total phosphorus (TP) and chemical oxygen demand (COD) loads of LPB non-point source pollution were estimated in 21 administrative institutions of Sichuan province in 2012. The results indicated that the generation, discharge and export loads of TN, TP, and COD in Sichuan province were 421860.34 t, 73183.22 t and 7192384.64 t, 169302.65 t, 23737.94 t and 3228082.48 t, and 97086.62 t, 13620.3 t and 1861604 t, respectively. In 21 administrative institutions, Aba was the maximum per area generation loads region of TN, TP and COD, while Suining was the region in which the surface water pollution caused by TN, TP and COD from LPB was the most serious. The results show that LPB non-point source pollution in some areas of Sichuan province are serious and controlling LBP non-point source pollution should to be attached importance.