Abstract: With the excessive chemical fertilizers and agricultural film put into the agricultural production, the non-point source pollution in the cultivated land has been aggravated. In this paper, the Hotan area in the lower reaches of the Tarim River Basin, Xinjiang, China is selected as the research area. Based on the PSR framework and the “input-output” principle of economics, the physicochemical data of cultivated land is added as a status indicator to construct an ecological risk assessment index system for the non-point source pollution. The spatial and temporal differentiation of the ecological risk level of cultivated land non-point source pollution in Hotan area in 1980 and 2016 is analyzed using the Arcgis software. The following conclusions are drawn from this study: The ecological risk level of the non-point source pollution in Hotan area in 2016 has been increased significantly compared with that in 1980. Particularly, the ecological risk level of the cultivated land in Moyu County and Yutian County has reached the highest V level, while Minfeng County is vulnerable due to its own ecological environment. The three counties can be used as pilots to promote non-point source pollution control. The research results can be taken as a reference for exploring the construction of non-point source pollution ecological risk assessment system, and guiding the development of differentiated non-point source pollution control according to regional characteristics.

Key words: Ecological risk assessment, Spatial and temporal differentiation, PSR framework, surface land source pollution, Hetian area