The Basic Properties and Heavy Metal Pollution Assessment of Road Area Soils in Taiyuan City Belt Expressway

To investigate influence of intensive human activities on soil environment quality in different functional zones in expressway road area,the study was conducted in different functional zones from Taiyuan city belt expressway. Toally 72 samples were collected from different functional zones. Analysis of physical-chemical properties including structure of profile,pH,soil texture,soil organic matter,the concentration of heavy metals of the soils were conducted. The results indicated that the source of the parent material of the road area soils was complicated and the soil profiles were disordered. Compared with soils from natural zone,the road area soils showed a trend of increasing soil pH,coarse particle contents,soil organic matter. The pollution by heavy metals in the road area soils was dramatic with the greening belt being the worst. The comprehensive pollution degree,as indicated by the pollution index calculated from the different heavy metal accumulation,is higher for the greening belt and central isolated belt and transaction and upslope and down slope and natural slope. Both the soil properties and the content of heavy metals exhibited a very remarkable spatial variability among the functional zones. Some ’zones’ with extremely polluted soil with heavy metals might exist in some locations. This should be taken into account of the environmental concerns.