Abstract: To clarify the spatial feature of agricultural non-point source pollution (ANPSP) and make reasonable pollutant control strategies in the Nansihu Lake Basin, Shandong Province, the pollution emission coefficient method was used to estimate the chemical oxygen demand (COD), total nitrogen (TN) and total phosphorus (TP) loads in the Nansihu Lake Basin. Equivalent standard pollution load method and GIS technology were used to analyze the pollution emission amount and emission intensity, sensitivity, and spatial characteristics. The cluster analysis was used to study the classification of the ANPSP. The results showed that the COD, TN and TP loads of Nansihu Lake Basin were 254574.06, 116976.87 and 15554.42 t in 2012, and the emission intensities of these pollutants were 88.18, 40.52 and 5.39 kg·hm^-2, respectively. Livestock and poultry breeding were the most important pollution source, while TN was the most important pollutant. The highest emission intensity occurred in Yanzhou City, Liangshan County and Yutai County, while the lowest in Shanting District. The highly sensitive areas and priority control areas were Yanzhou City, Wenshang County, Liangshan County, Dingtao County and Tengzhou City for the whole Nansihu Lake Basin, and the livestock and poultry breeding were the key pollutant source of these regions. It is concluded that rural domestic pollution has the highest pollution contribution rate, while comprehensive pollution is hard to control.

Key words: soil salinization, Mu Us desert-loess plateau transition zone, spatial heterogeneity, influencing factors