Study On The Infuluence Factors Of Heavy Metals' Enrichment In Chang-zhu-tan District

Along with the development of society and economy in our country, the heavy metals' enrichment in soil has become increasingly threat to humanity's food security and their health. By analyze the domestic and foreign present researches, this paper realized the insufficiency of the analysis of the factors which influence the heavy metal' enrichment in soil. By means of spatial analysis in Geographic Information System and statistical methods (ANOVA, Correlation analysis), the affect of the natural factors, such as river, terrain, wind direction, soil type, soil's pH, as well as the social factors, including spatial relations between samples and city, the city's main functions, on the spatial distribution of heavy metals in soil, have been studied in the Chang-Zhu-Tan District. The main conclusion includes:1. The study area, heavy metals in soil enriched with the relevance of the traditional definition of soil taxonomy in the soil characterization Obviously, such as the purple soil in the red soil and the content of heavy metals are significant differences, while the mother of soil classification definition of the types of soil Between the content of heavy metals there was no significant difference.2. Along with the increase of the distance from the city, the pH and the content of heavy metal in soil reduced gradually, which indicated that the pH and the content of heavy metal have been influenced directly.3. The content of some elements, such as As, increased along with the increase of the distance from the Xiangjiang River, which indicated that the enrihchment of heavy metals in soil has been influenced by the water system in the study area.4. The heavy metals' content in soil is more pronounced in the wind direction than other area, which indicated that the wind direction influenced its enrichment. The result of the diffusion simulation of refinerys' smoke by Gaussian model also shown that the wind direction influenced the heavy metals' enrichment by influence the spatial distribution of dust.5. The different contents of heavy metal in different functions of city indicated that the human activity is also a key factor of enrichment. Particularly the effect of different types of industrial is different, the greatest influence have been brought by non-ferrous metal refining and chemical industry.To sum up, natural factors and social factors common role in the heavy metals' enrichment and spatial distribution in study area.