The Heveay Elements's Distributive Characteristics And The Warning Model Of The Soil In Taiyuan Basin

In this paper,the sources and distribution law of 8 heavy-metal elements Cd,Cr,Hg,Ni,Pb,Zn,As,and Cu in the soil of the Taiyuan Basin are researched by such methods as contour map,multifractal, system dynamics modeling etc,and the early warning model of eco-geochemistry is set up based on the geochemical data. The material works and the achievements are as follows.First of all,the background values of the soil in TaiYuan Basin are calculated on the basis of the deep soil data tested,according to the iterative eliminate average value method. Comparing the shallow layer's data with the background values, we analyze the pollution status of the soil in the basin, and suggest that the three elements of Hg,Cd,As are the most serious in pollution. Tracing the sources of the heavy metal elements by associating with the distributive situation of the industrical and mineral enterprises indicates that the elements were principally expelled from the factories.Secondly,the multifractal pictures of 8 heavy-metal elements are drawn under pairs of logarithm coordinates by using the data of shallow and deep layers of the soil in the city and the basin. Statistic analysis of the influence and function in the ecological environmental and the fractal law of the heavy-metal elements show the order of significance of the influential factors, and it is suggested that the Taiyuan city is seriously polluted by Cd,Hg,and the pollution trend of Ni is to strenthen while Pb is reducing.Comparatively,in the Taiyuan basin,the pollution trend of Hg is to strengthen and Cd' s reducing.Finally,using the theory of System Dynamics,we have carried on modeling through the basin geochemical data in virtue of the software. And according to multifracal' s result of elements, adopting sample average value to limitate prewarning of the pollution trend of the heavy metallic elements, we have gained the early warning value and maded comprehensive prewarning illustration. Furthermore,we have proved thatthe application of the model of System Dynamics is feasible in Eco-geochemistry,and have pointed out the disadvantage of the model. In this paper we has also put forward suggestions worth referencing for the farther application of the early warning model.