Spatial Variablity Of Total Nitrogen And Organic Matter Of Soil Based On GIS In Lanzhou

The properties of soil are not homogeneous, whereas soil is a continuous spatio-temporal heterogeneity, with high spatial variability. which not only is reflected in the time, but is also reflected in the space. The traditional methods of describing soil properties are on the whole qualitatively soil classification, not researching soil spatial variability quantitatively.Geostatistics was applied in soil science field to estimate the distribution of soil properties, and to determine the spatial scales and forms of the soil variation, in order to give rise to the validity of sampling, it also can be used to study the process of the soil variability. the theory and method of geostatistics are currently still one tide of reseaching spatial variability quantitatively both at home and abroad. with population applying of GIS and developing of geography ,it has been a hotspot to use the combination of the information system (GIS) and the geostatistics to study the soil spatial variability today.With the help of the traditional statistics method and geostatistics and GIS. the thesis regard lanzhou city as study area, the result of studying on the spatial variability of total nitrogen and soil organic matter can be showed:(1)Research on the Lanzhou soil nitrogen and organic matter by traditional statistical methods shows that the content both the soil nitrogen and the organic matter were high variation, is 1.067 and 1.400, for the type, the data distribution of nitrogen and organic matter were normal , which meet the prerequisite for the study of spatial variability of soil .(2)The results of the variogram function analysis shows there are the space-related between the soil nitrogen and the organic matter in a certain study scope, namely, the spatial variability structural characteristics. Soil nitrogen and organic matter spatial variability increases with the distance, which is variogram value increased with the distance, and has the Sill, which shows the value is space-related in a sample spacing distance.(3)The analysis of variogram function model shows that the most fitting model of the soil nitrogen and organic matter are spherical model, and isotropic and anisotropic analysis shows that the distribution of soil nitrogen and organic matter is different in different directions .(4)The soil nitrogen and organic matter maps by Kriging method reflects the spatial variability characteristics , the distribution of nitrogen and organic matter is similar in study area, high-value areas are located in the south and central of the Lanzhou. This also shows that the soil nitrogen and organic matter has the high correlation.