Soil Environmental Evaluation Model Based On Cokriging Interpolation And Spatial Factors

According to the evaluation diffculties of soil pollution, Kriging interpolation is improved in this thesis. It makes it suitable to the reality of the soil environment, and can be able to more accurately reflect the extent of spatial variability of the soil pollution.This thesis takes some southern areas as an example, considers factors such as DEM, river, and the earth's surface, and uses this method to interpolate. At the same time, it contrast the Neimeiluo pollution index model, the ordinary Kriging model and DEM Kriging model, then get a much better space count model. The main contents are:(1) Nemero index for the model of heavy metals was used in the soil Pb comprehensive evaluation. According to the study, we can obtain the soil pollution levels of the various sub-areas, and the results were evaluated.(2) Kriging method was used to evaluate the spatial variability of the Pb in the study areas. From the results, it can be concluded as following: in the large scale, because of the topography, and other spatial factors, ordinary Kriging methods can not well reflected the spatial variability of the soil pollution.(3) Because of the inapplicability of the ordinary Kriging, an improved method was developed in this thesis. The regional elevation sampling and remote sensing images ware studied to form DEM model and extract river line. Finally, the study area was divided into smaller areas according those facts. Then the modle based on Cokringing and spatial facts was used to get Pb on the comprehensive evaluation of spatial variability.(4) Compareing the accuracy of the evaluate results of the three models at last. Throught comparison, the third method is the best.