Analysis of the spatial and temporal characteristics of total nitrogen non-point source pollution in Shaanxi Province based on DPeRS model
In order to clarify the temporal and spatial distribution characteristics,pollution types and pollution control areas of total nitrogen(TN)non-point source pollution in Shaanxi Province,diffuse pollution estimation with remote sensing(DPeRS)model was used to evaluate the temporal and spatial distribution characteristics of non-point source pollution load and pollution sources in Shaanxi Province from 2016 to 2020 by remote sensing pixel scale(30 m).This paper identifies the main types and optimal control units of non-point source pollution,and discusses the contribution rate of non-point source pollution to surface water pollution.The results show that the average discharge load of TN non-point source pollution is 1.25 t·km-2,with the amount of river entry being 8.31×104 ton in Shaanxi Province from 2016 to 2020.The discharge load of TN non-point source pollution shows a trend of first decreasing and then increasing,and the amount of river entry shows a trend of fluctuation with the interannual change.The TN non-point source pollution is relatively serious in the Yellow River basin,especially in the Weihe River basin,and the high-risk areas of entering the river are mainly distributed in the plain planting areas of the Weihe River basin.Farmland runoff is the primary type of non-point source pollution of TN in Shaanxi Province,followed by soil erosion.Among the 49 control units in Shaanxi Province,the average number of TN non-point source pollution control units is 24 from 2016 to 2020,accounting for 61.21% of the average area,and the optimal control units of Class Ⅰare mainly distributed in Weihe River basin.In addition,the average contribution rate of TN non-point source pollution to the total nitrogen of surface water quality was 46.51% in Shaanxi Province from 2017 to 2020,and the average contribution rate of agricultural sources was 41.87% .The prevention and control of TN non-point source pollution in Shaanxi province focuses on the optimal control unit of non-point source pollution in the Yellow River basin,especially the control of farmland runoff in the Weihe River basin.
万方数据
维普
