Spatial Analysis And Pollution Evaluation Of Heavy Metals In Xihuang Section Of Weihe River Basin Based On

Soil is a non-renewable resource, but also a variety of contaminants in environmental media. Spatial analysis of the distribution of heavy metals in soil and its influencing factors, soil pollution assessment and control, to improve the quality of life, the protection of human health significance immeasurable. In this study, the Weihe River West Ham section of heavy metals in soil as the research object, through field surveys, system and deep soil surface samples collected in the region, measured soil heavy metals As, Cr, Cu, Ni, Pb, Zn content of the six elements and organic matter content and soil particle size, combined with study area terrain data and meteorological data, the test analysis and mathematical statistics, the use of single-factor analysis of variance, multivariate analysis of variance, correlation analysis and analysis methods, such as Kriging spatial difference studied Weihe heavy metals in the soil space segment River Basin West Ham distribution and its influencing factors (slope, aspect, elevation, land use type, soil type, soil depth, mean annual temperature, annual precipitation), between the various elements of the soil heavy metals and other soil properties correlation between, and on this basis, the soil environmental quality in the study area were evaluated. The main draw the following conclusions:(1) physical and chemical nature of the statistical characteristics of soil:Soil As content in the range of the study area is8.14-13.79mg/kg, Cr content in the range of122.55-125.52mg/kg, Cu content in the range of23.88-25.32mg/kg, the range of Ni content is33.49-34.43mg/kg, the range of Pb content is24.93-29.22mg/kg, Zn content range is46.57-52.13mg/kg. Shaanxi Province, with the national and the average content of heavy metals in soil compared to Cr content in soil in the study area were2times the national average and the average of multiple Shaanxi Province, As, content with the national average Cu, Ni, Pb and Shaanxi average comparable level. Content of six metallic elements are moderate variability, variability metal As content is relatively large. Metals Cu, Pb and Zn variation similar, are gradually decreased from the surface to the deep content. Soil organic matter content of the study area ranges6.37-15.41g/kg, mainly in the plow layer above the surface of20cm, with increasing depth, soil organic matter content decreased. The coefficient of variation in the range of37%-52%, a moderate degree of variation. Soil particle size of the study area is the main component of coarse particles, which range from50.31%-52.79%, and has gradually increased with depth trends. Sort other content of soil size fractions:fine silt> in silt> clay> in the sand> coarse sand, gravel content is almost zero.(2) spatial distribution of heavy metals in soil:Soil metal Cr, Cu, Ni, Pb, Zn content in high value areas located in the study area southwest of metal As high value content mainly in the northern part of Xianyang Changwu and liquan County, Sanyuan County. Metal content of the soil is generally higher than in Xi’an, Xianyang, the metal content of the soil. Metal content and deep soil surface metal content less, except As elements of other metal elements variation in Xianyang City is gradually decreased from south to north. Metals Cr, Cu, Pb and Zn enrichment with surface effects, including effects of Pb enrichment stronger. Metal Cu, Ni, Pb enrichment of the soil surface exceeds the national average more metal As, Cr, Zn enrichment of the surface is slightly higher than the national average(3) the relevant characteristics of heavy metals in soils:soil layers each study area, a good correlation with metal As Pb, As and Zn, Cu and Ni, Cu and Zn, Ni and Zn between, As and Cu, Pb and Ni, Pb and Zn correlation between weak. Weak correlation metals As, Cu, Ni, Pb, Zn and Cr elements. In different soil depth between60-70cm soil layer metallic element relevance best. A significant positive correlation between the correlation between As, Cr and organic matter in the soil in the study area between weak organic matter content and metal Ni, Pb, Zn, Cu. Metal Pb and organic matter in surface soils mainly a strong correlation, and correlation between As and Ni in soil and organic matter mainly50cm or less.(4) of heavy metals in soil:terrain factors, factors affecting elevation metal As, Cu, Ni, Zn content is more significant, the slope of the metals Cr, Ni has a significant impact, slope factor of six metallic elements are have a significant impact. Pairwise comparison showed that, As, Cu, Ni, Zn four elements in different elevation changes of the group is the same, the order is the largest group of400-800m,<400m, followed by group metal content,>800m set minimum. Metals Cr, Ni content increases with the slope with the trend. As a high content of sunny soil, the soil Cr shady and semi-shady areas, Zn, Pb, Ni content is higher. Characteristics of Cu and Ni metal distribution is similar with the slope, indicating that these two metals have a strong correlation.(5) evaluation of the study area:the consolidated accumulated pollution index in the study area were2.06loess soil Shaanxi, Shanxi black loam1.60,1.59off the loess soil. Single factor Shaanxi loess soil, Shaanxi black loam, Guanzhong loess soil accumulated pollution index order were:Pb> Cr> Cu> Ni> As> Zn; Cr> Pb> Ni> Cu> Zn> As; Cr> Pb> Cu> Ni> As> Zn. Description section of the Weihe River West Ham has a certain accumulation of heavy metals in the soil, where the maximum cumulative pollution index Pb and Cr of3.34and3.02, respectively. Soil heavy metal pollution status of the evaluation results of the study area are:single factor pollution index is the average of the order of Ni> Cr> As> Cu (farmland)> Zn> Cu (orchard)> Pb, single factor pollution index of six metallic elements are less than0.7. Soil heavy metal pollution index was0.46. Description of soil environmental quality of the region as a clean and safe condition.