Temporal and spatial assessment of total phosphorus from non-point source pollution in Weihe River basin,Shaanxi Province
To clarify the spatiotemporal distribution characteristics of total phosphorus from non-point source pollution in the Weihe River basin(Shaanxi section),this study adopts the DPeRS model,which has a high degree of spatial refinement.The spatiotemporal distribution characteristics of total phosphorus emissions and inflow loads from non-point source pollution in this study area are evaluated at the pixel scale from 2016 to 2020.The results indicate that the temporal and spatial variation characteristics of total phosphorus non-point source pollution load in the study area have strong correlation with precipitation characteristics,and are also related to regional land use distribution characteristics.The high-value areas of total phosphorus emissions and inflow loads from non-point source pollution in the study area are mainly concentrated in the grassland area in the northern part of the basin,and their pollution types are mainly soil erosion.Farmland runoff is the main pollution type in the high emission load areas of western Weinan and central Xianyang in Guanzhong Plain.The total phosphorus inflow load of non-point source pollution in the study are showed a trend of first increasing and then decreasing(2018 was the turning point)from 2016 to 2020,which was related to grassland soil erosion of non-point source pollution caused by precipitation change in the high-load area in the northwest of the basin.The key period for the prevention and control of total phosphorus non-point source pollution is from June to August every year in the study area.Among the three key sections in the watershed,the main type of total phosphorus non-point source pollution in the catchment area where the Linhe River enters the Weihe River section is farmland runoff.The dominant type of catchment area where the Chakou and Xinhe River entering the Weihe River section are located is soil erosion.Among them,the average contribution rate of total phosphorus non-point source pollution to the total phosphorus index of water quality reached 77.38% in the catchment where Chakou section is located from 2017 to 2019.It is suggested that the upper and middle reaches of the catchment should focus on forest soil and water conservation,and the downstream areas should focus on strengthening the prevention and control of non-point source pollution from farmland nutrient management.
non-point source pollutionDPeRS modelWeihe River basinkey catchment area
万方数据
维普
