Spatial Distribution And Genetic Analysis Of Heavy Metals In Groundwater In The Front Plain Of Yanshan Mountain

Groundwater resource is an important part of water resources,Nearly 70% of the country’s population of drinking water is from groundwater resources.Therefore,groundwater is an important source of drinking water,and the quality of groundwater has become a prerequisite and an important guarantee for safe water supply.Based on the groundwater pollution investigation and evaluation data,this paper aims to reveal the causes of the formation and spatial distribution of heavy metal in the groundwater in the study area.With the help of multivariate statistical analysis,typical hydrogeological profile analysis and geostatistical analysis,to explore characteristics and genetic analysis of spatial distribution of heavy metal content in groundwater.Principal results are as follows:The contents of different indicators in the study area are quite different.The spatial distribution of the indicators is not uniform,among which the main indicators are Mn,Fe,and As.The hyperbid rates are 35.87%,18.2%,and 13.97%,respectively,in the alluvial-fan and flood plains.The content in the bordering area is relatively high,which is caused by the combination of various factors such as the hydrogeological conditions,the acid-alkali environment,the content of organic matter,and the presence of the salt water zone on the edge of the Chaobaihe alluvial fan.The original data of each index has a large degree of variation,which does not meet the standard normal distribution.The logarithmic transformation of the original data reduces the degree of variation of the transformed data,which is basically consistent with the normal distribution.Through geostatistical analysis of groundwater heavy metals in the study area,it was found that all heavy metal indicators of the groundwater in the study area are moderately spatially related,and spatial variation is controlled by both random and structural factors.Among all the heavy metal indicators,the spatial variation of Cr(VI),As,Fe,Cu,and Mn was dominated by structural variations.It had strong spatial correlation and was mainly controlled by structural factors and random factors from human is smaller.The spatial variation of Pb,Hg,Zn and Cd is dominated by random variation,and the spatial correlation is weak,mainly controlled by random human factors.The genetic analysis of heavy metals in groundwater was carried out by means of multivariate statistics and typical sections,it was found that Hg,Pb,Cd and Zn had poor correlation with conventional hydrochemical indexes,and their distribution and migration are greatly affected by human activities;The higher contents of Fe,Mn,and As are distributed continuously and their distribution ranges are similar,in the central plain area in a laminar manner,with homologous relationship.In a typical section,the content of Fe,Mn and As gradually increased along the direction of underground water flow,and Eh gradually decreased,indicating that the reduction environment was conducive to the release of Fe,Mn and As.The results of Cr(VI),Cu cluster analysis and factor analysis show that the two are very similar in origin,and distribution environment is mainly related to the redox conditions.