Risk assessment of soil Cd exceedance in the Wuhan Donghu High-tech Developing Zone by disjunctive kriging

144 soil samples were collected in the Wuhan Donghu High-tech Development Zone, and the contents of soil Cd were measured. Statistical results show that the contents of soil Cd have an average value much higher than its background value, and exceed the second-class standard of the National Environmental Quality Standards of China in the whole study area. Local Moran´s I detected 10 outliers which were excluded in the calculation of the experimental variogram and variogram model fitting. The map of the estimated probability distribution of Cd was generated by disjunctive kriging with a threshold of 1 mg/kg. The probability of pollution was more than 50% in the most part of the study area. In the middle of the area higher probability was observed, which may be related with the industrial emissions around the South Lake and Tangxun Lake. Therefore, proper measures should be made to reduce the pollution.