Using Rule-Based Model To Identify Source Of Heavy Metals In Soil Of Guangdong Province And Analyse Its Influencing Factors

The risk of heavy metals contamination in the soil is well known.It is of great significance to distinguish the natural and anthropogenic sources of heavy metals in soil to control the pollution of heavy metals in soil and guide the distribution of related industries.On this basis,it is important to identify and analyze the influence factors of heavy metals in soil on the early warning,simulation and prediction of heavy metals in soil.The influencing factors of soil heavy metals are extremely complex.Soil heavy metals may be derived from natural or anthropogenic sources.Traditional methods,such as isotope tracer method and principal component analysis,can be used to identify the source of heavy metals in soil.However,these methods can only analyze the source of heavy metals in soils,it is not possible to determine quantitatively the factors affecting soil heavy metals in different sources.Heavy metals in soil can be divided into different rules by Rule-Based model,and unbiased estimation for each rule.The results of Rule-Based model include the contribution of different factors to the model.Defining the natural and anthropogenic sources of heavy metals in soils by the contribution of factors and the different rules of the model,identifying the main driving factors to the distribution of heavy metals in soil,analysis main influencing factors of heavy metals in soil,and identification main sources of pollution.The Cr,Ni,As,Cu,Pb,Zn,Cd,and Hg of eight soil heavy metals in the soil of Guangdong Province under different soil and different land use patterns were studied objects,106 factors which may influence the heavy metals in soil were selected according to the relevant literature,using the idea of big data analysis and data mining,to distinguish the natural and anthropogenic sources of heavy metals in soil and identify the driving factors of heavy metals in soil.The main conclusions including,1)on the whole,the soil Cr,Ni,Pb,Zn,As,Cu and Cd elements in Guangdong province were mainly affected by natural factors,Hg elements were significantly affected by human factors.2)The main factors affecting the distribution of Cr elements in soil are geology and watershed,Pb elements are total potassium content in soil,Zn elements are total phosphorus content in soil,Ni elements are geology and soil gravel,and Cd elements are pH and total phosphorus content in soil,Hg elements are soil chrysene content and total phosphorus content,and As elements are geological types and soil gravel content,Cu elements are soil total phosphorus content and geological types.3)Soil Cr pollution from agriculture,industrial activities and transportation.Ni and Pb pollution mainly from agricultural activities.Soil Zn pollution mainly comes from agricultural activities,in addition,some of them come from industry and transportation.Soil Cd pollution mainly comes from agricultural activities>industrial activities.Soil Hg pollution mainly comes from agricultural activities,in addition to part of the traffic activities>the river water quality>industrial activities.The soil As pollution mainly comes from industrial activities>the river water quality.Soil Cu pollution may be derived from agricultural activities>traffic or industrial activities.The results of this study have an important significance for guiding the industrial layout and controling soil heavy metal pollution in Guangdong Province.