Based On GIS Spapial Distribution And Pollution Ofheavy Metals In Soil

With the rapid development of China’s industrialization, urbanization and the social economy, a large number of harmful heavy metal material which were released in the process of human daily life, through the circulation into the soil, not only affect the structure and function of soil deterioration, resulting in decreased soil quality, but also directly harm to human health and development. Therefore, to study the distribution of soil heavy metals pollution condition and its spatial difference, and related to soil environmental quality evaluation, the urban ecological geochemistry evaluation and urban soil pollution control has very important theoretical and practical significance.In surface soil of X city As the research object of this study, through field survey to collect data and field test was analyzed, in X city of soil arsenic(As), chromium(Cr), lead(Pb), copper(Cu), zinc(Zn) conducted a study of five kinds of heavy metal element content, surface soil samples collected 685, using the method of multivariate statistical analysis, statistics, research of X city surface soil heavy metal content of the overall change rule and spatial distribution difference; And, according to the results of the analysis by means of single factor pollution index evaluation method and inside plum comprehensive pollution index method and combined with Gis technology, to the degree of surface soil heavy metal pollution in X city. The main results were as follows:(1)The scope of soil heavy metal content in X city as follows: As 0.72~40.55mg/kg, Cr 13.87~329.82mg/kg, Cu 10.24~328.56mg/kg, Pb 0.69~171.26mg/kg, and Zn 16.00~683.84mg/kg in X city. Through the analysis of the variation coefficient, Pb >Zn > As = Cu > Cr. Degree of variation of Cr belonged to the weak variation, Degree of variation of Cr belonged to the strong variation.(2)The evaluation results showed that soil heavy metal pollution in single heavy metal pollution evaluation, the surface soil in the whole city was not As, Cr, Cu, Pb, Zn heavily polluted area were 86.81%, 66.36%, 69.73%, 59.67% and 56.13%, respectivelyl; Meanwhile, there existed the mild and moderate pollution of five heavy metals in each area in X city; In addition to the heavy metals As, there were four heavy pollution of heavy metal pollution area in X city, the severe pollution area of Cr, Cu, Pb, Zn accounted for the total area was 0.54%、1.57%、2.77%、2.12%, respectively. Heavy metal pollution degree sorting as follows: Zn > Pb > Cr > Cu > As.(3)Comprehensive soil heavy metal pollution evaluation results showed that the surface soil X city clean area was occupied 5.80%, 27.05% of the total area was clean area, light pollution area was occupied 55.72%, moderate pollution area was occupied 9.53%, severe polluted area accounted for 1.90% of the total area. Our caravan left CL county of X city in the south of the surface soil subjected to heavy metal pollution area was the shortest, the largest area in surface soil polluted by heavy metals was QL County.