| This thesis takes a smelting slag field as the research object. After taking full account of local circumstances the actual terrain, this thesis laid out a total of 102 sampling points and 8 control points and analyzed the total content of 4 heavy metals in the collected samples. Through the comparison of 4 Kriging interpolation methods, the results of optimal interpolation method and spatial distribution of heavy metals in the smelting slag field affecting areas were got. And through evaluation of the 4 heavy metals pollution, the visual map of heavy metal pollution was got. Research methods and contents of this paper are following:(1) After the determination of the total content of four heavy metals and the judgment of outliers, the results revealed that: compared with the background values, the arithmetic average of As, Zn, Cu and Cd were respectively 720 times the background value, 11.6 times the background value, 18.5 times the background value and 8.1 times the background value.The results of the normal examination of all the values in Minitab revealed that, the values of Cu total content were normally distributed, the values of As, Zn and Cd after BOX-COX conversion in Minitab software were also in line with Gaussian distribution.(2) The spatial distribution of heavy metals were quantitatively analyzed. After the calculation and model selection in the GS+ software, the Co/(Co+C) values of four elements were got. The results revealed that Cu and Cd had strong space correlation, they were influenced mainly by structural factors, such as water, wind and other natural factors, their distribution were also affected by human activities outside the scope; As and Zn elements had moderate space correlation, it indicated that both natural factors and human factors influenced their distribution.(3) After the analysis of spatial distribution of heavy metals, the best fitting models of each element have been selected. Interpolation of each element was taken with respectively Simple Kriging, Original Kriging and Universal Kriging methods after analysis results in ArcGIS software. For the four elements of the spatial distribution of heavy metals within the optimal interpolation method was selected according to Mean-Standardized, Root-Mean-Square, Error Average Standard Error, Mean Standardized Error and Root-Mean-Square Standardized Error as the comprehensive standard. The results showed that the optimal interpolation of As, Zn, Cu and Cd were respectively: OK, OK, OK and SK. The figure of interpolation results revealed the distribution of all the 4 elements content decreased from the slag field to the town area, and the content of heavy metals near slag field was in more rapid decline. Distribution was also somewhat different in different heavy metals.(4) Single factor index method, geological accumulated index method, the potential ecological risk index and the Nemerow comprehensive index were used respectively to evaluate 4 heavy metals pollution, and the distribution map was got by interpolation of assessment values. The results revealed that: Evaluation of three single-factor index results of the evaluation of heavy metals pollution are consistent in general, but due to the different classification standards of pollution among the three methods, the results were somewhat different, results showed that the ecological risk index was relatively the best. In the whole research area, from the view of space distribution we can got that Rentoushan and Putuoyan near the slag field suffered the most serious pollution, while the control point Qinglongju near the town suffered the relatively lightest pollution. From the view of element, Most pollution of the slag field was caused by the overall excessive content of As, there were also of excessive phenomenon of the rest 3 heavy metals in different degrees. Under the action of all the 4 elements, the most research area had serious pollution of heavy metals.
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