| The element contents and its spatial characteristics in Uzbekistan topsoils were studied with the methods of classic statistics and geostatistics. Firstly, using the software SPSS 15.0 for windows, the average values and coefficient variations of topsoil elements were calculated. The element contents（Ca, Na, Mg, Co, Be, K and Zn） of Uzbekistan are higher than their median values of world soil, and the other, the stable elements such as Al and Fe are lower. The geochemical active elements（Ca, Sr, Mg and Na） have significant differences with the stable elements such as Al, Fe and so on. Then, the element contents and its spatial distribution in Uzbekistan were analyzed with the software of Gs+. The results showed that the stable elements（Al, Fe, Be, K and Ti） in the topsoil have a strong spatial autocorrelation; the heavy metals（Cu, Pb and Zn） and nutrient element P are influenced by the small-scale factors including fertilization, irrigation, industrial and agricultural production, which have not yet reached the extent of the destruction of their original spatial patterns. The geochemical active elements（Ca and Sr）are affected not only by the soil parent material but also by a certain degree of local random factors, which lead to no spatial autocorrelation. In order to assess the current status of heavy metals in Uzbekistan topsoils, Hakanson potential ecological risk index was used to conduct a preliminary assessment of potential ecological dangers of heavy metals in Uzbekistan topsoil. The potential ecological risk index of Cu, Cr, Zn and Pb are small and the degree of ecological hazard is light, which is consistent with the Uzbekistan′s social and economic development. |
