Analysis of Nitrate Nitrogen Pollution Sources and Identification of Influencing Factors in Shallow Groundwater in Weishan Irrigation District
Nitrate nitrogen(NO3--N)pollution problem in China is prominent,among which the NO3--N pollution problem of shallow groundwater in agricultural regions is particularly serious.To investigate the current status and sources of NO3--N pollution in shallow groundwater,the spatial and temporal distribution characteristics of NO3--N concentration in groundwater and its main influencing factors were analyzed in the study area of the Weishan Irrigation District,based on the water quality data of shallow groundwater from 2019 to 2021.An absolute principal component score-multiple linear regression model(APCS-MLR)was employed to identify sources of NO3--N pollution.The results showed that the groundwater NO3--N concentration in the Weishan Irrigation District presented an increasing annual trend from 2019 to 2021,with a severe exceedance rate of 21.43%in 2021.The high values of NO3--N concentration mainly appeared in the flood season(i.e.,June to September)and increased with precipitation;meanwhile,the NO3--N concentration showed a tendency of gradual increase from the southwest to the northeast.Groundwater NO3--N concentration was also closely related to the groundwater depths,land use types,agricultural activities,etc.The risk of NO3--N pollution was higher in the cultivated lands of the shallow groundwater depth regions.The results of source analysis revealed that groundwater NO3--N pollution in the Weishan Irrigation District was mainly affected by three factors:agricultural activities(48.94%),leaching enrichment+faecal effluent(39.09%),and redox environment(2.61%).The results of this study can provide scientific basis for the prevention and control management of groundwater NO3--N pollution in Weishan Irrigation District.
shallow groundwaternitrate nitrogensource analysisAPCS-MLRWeishan irrigation district
万方数据
维普
