Application of principal component analysis and cluster analysis to evaluation of black soil degradation in Jilin

The black soil region in Jilin Province is one of the main commodity grain production base in China, but its soil has began to appear degradation and destruction on different degree. With the aim to study the degradation mechanism of black soil for protecting the geo-environment, we conducted the field investigation and chose twenty-nine items, carrying out principal component analysis on twenty samples of different areas and depths in Jilin Province. Principal component analysis is used to reduce the dimension of the evaluation factor. Twenty-nine factors were classified into seven uncorrelated principal components, which reduced the complexity in analysis process. And it adopted cluster analysis method to make sorts of twenty samples into three black soil degradation grades. The result preferably coincided with practical situation of the degradation of black soil in Jilin. Some effective suggestions were proposed according to the result of soil degradation.