A CONTINUUM APPROACH TO SOIL CLASSIFICATION BY MODIFIED FUZZY K-MEANSWITH EXTRAGRADES

The need for a more continuous approach to soil classification is disc ussed, and methods based on the mathematical constructs known as fuzzy sets are considered most appropriate for this. A centroidal grouping method, fuzzy k-means with extragrades, which quantifies the intragrad ing and extragrading of soil individuals is described. An example of t he application of this technique to an area of 4800 ha at Wesepe in Th e Netherlands is presented. The results show that the technique could create a classification that reflects the main pedological features of the area in a continuous way. Although there may be problems in selec ting the optimal number of groups and degree of fuzziness, we conclude that the method is most promising and worthy of consideration when an y type of quantitative soil classification is required.