Analysis on the contribution of non-point source pollution of grassland river in northern China based on remote sensing technology
In order to explore the influence of non-point source pollution on grassland river in northern China with small population density and insignificant surface runoff,and to support the objective evaluation of regional water environment quality,this study takes the Shandian River basin as an example,focusing on the unclear sources and contributions of CODCr and CODMn pollution in the Baichengzi section during flood season,on the basis of satellite remote sensing technology,a multiple technical approach was applied that integrated ground monitoring,experimental simulation and model evaluation to analyze the non-point source pollution of water-level fluctuation zone and soil erosion in the study area from 2020 to 2022 comprehensively,and the contribution of non-point source pollution to Baichengzi section water quality was quantitatively analyzed based on the measured data of water quality and the estimated data of river discharge by remote sensing.The results show that the non-point source pollution from water-level fluctuation zone in the study area is characterized by grassland output>feces output>bare soil output.The average contribution rate of non-point source pollution from the water-level fluctuation zone to CODCr and CODMn in Baichengzi section reached 70% from May to September,and the level of non-point source pollution from soil erosion was slight,which average contribution rate was less than 1% .According to the statistic results of natural and human diffuse pollution outputs,the increase of CODCr and CODMn concentration in Baichengzi section from May to September was mainly influenced by natural factors,and the average contribution rate of natural non-point source pollution to water quality in Baichengzi section reached 65% in three years,while the contribution rate of human non-point source pollution was less than 10% .This study effectively evaluate the environmental impact of non-point source pollution in northern grassland river,especially objectively analyze the impact of natural factors and human activities on the unstable water quality,which can provide technical support for the implementation of the objective evaluation of water environmental quality with"monitoring first and flexible assessment".
万方数据
维普
