Classification of natural grassland based on catastrophe progression method

Based on catastrophe theory, catastrophe progression method of natural grassland classification was put forward to provide reference for the quantitative study on natural grassland classification. Three factors including ecological situations, reproduction abilities and economic conditions of natural grassland were taken into accounted synthetically in this study, and the hierarchical index system for natural grassland classification was constructed. On the basis of the relevant researches, the natural grassland was divided into 3 grades: temperate desert type, temperate steppe type and meadow grassland type, and 18 natural grassland samples from western Junggar Basin, Sinkiang, China, were selected as the training samples, and the catastrophe progression recognition criteria were presented. The additional 13 natural grassland samples were selected as the testing samples, and evaluated to verify the feasibility and reliability of the proposed catastrophe progression recognition criteria. The study showed that catastrophe progression method could better reflect the resources attributes of natural grassland, and the classification results of 13 natural grassland testing samples were reasonable, and agreed well with that of grey relational analysis method, projection pursuit method, projection pursuit dynamic cluster method, set pair analysis method, and the selforganizing feature maps (SOFM) neural network method.