Assessment And Spatial Distribution Of Soil Heavy Metals Pollution In Different Traffic Belts

City Soil as constitute an important part of city environment,is the basis of human production and life,frequent human activities make the city soil polluted by heavy metals in different degree,resulting in a negative impact on the city ecosystem and human health.To identify the source of soil pollution,soil pollution assessment of the severity and Research on soil pollution control measures,to evaluate and judge the current situation of ecological environment,for economic and social development and environmental protection policy,planning,improving environmental quality,accelerate the construction of ecological civilization,has important significance to build ecological full filled the environment short board of well-off society.In this paper,the three District of Wuhan city(Wuchang District,Hongshan District,Qingshan District)as the study area,the sample collected from the study area of traffic link and traffic zone,collected 53 sample points in traffic link in traffic with a collection of 90 samples,a total of 143 sampling points.The extraction in the laboratory based content of soil As,Cd,Cu,Cr,Pb five kinds of heavy metals,using data analysis to reveal the content and distribution characteristics of heavy metals in surface soil in the study area,through the single factor evaluation,comprehensive evaluation and potential ecological risk assessment of the pollution degree of heavy metals in surface soil and the city the potential ecological risk assessment,finally analyzes the pollution mechanism and countermeasures.The result shows:(I)As a whole,the soil environment in the study area is better.The pollution degree of soil heavy metal in the overall research of light pollution,143 sampling points,two national standards more than only the Cd and As elements,Cu,Cr,Pb three elements were not more than two national standard value,and Cd,Pb and Cu were significantly correlated.The pollution degree of the two ring road and the three ring road is relatively heavy in each traffic link;the pollution degree in each traffic belt is three ring belt>two ring belt>one ring belt>outer ring>Outside the outer ring.The conclusions of the three evaluation methods are consistent.The conclusion of the three methods is that the two ring road and the third ring belt are moderately polluted,and the other areas are mild polluted.(2)According to the distribution characteristics of soil heavy metals in the study area,ARCGIS software was used for spatial interpolation of each element,and then according to less than the background values of soils in Hubei Province,Hubei province to the national soil background value standard,national standard and national standard level two,more than two national standards four interval reclassification that,the spatial distribution characteristics of elements.The results show that the As elements of point source pollution in the study area,the overall content of less than two national standards,in a safe state;Cd enrichment is obvious,and the spatial distribution characteristic of the urban center outward pollution level gradually weakened,the element is in the middle pollution condition;three kinds of elements Cr,Cu,Pb no more than two national standards,but most of the region is between the national standard and the national standard level two,that is close to the critical point of pollution,should cause enough attention.(3)The mechanism of soil heavy metal pollution in the study area is related to the natural process of soil,that is,soil,soil,parent material,weather and geological changes.Because there is little difference between the side ring line traffic pollution and traffic zone,indicating that the main source of heavy metals in the soil is not roadside transportation but natural process.On the other hand,it is related to human activities,including agricultural activities,industrial pollution and traffic activities.Within the Third Ring Road of the study area,the regional economy is developed,the population is dense,and the industrial pollution is relatively heavy.Therefore,compared to the outer ring road,the soil pollution within the Third Ring Road of the study area is serious.