China land cover monitoring in mountainous regions by remote sensing technology — Taking the Southwestern China as a case

Land cover products are the important background for scientific researches. There are several land cover data sets at regional or global scales. However, in the Southwestern China where are the typical mountainous regions, it is usually more difficult to map land cover products because of the high proportion of complex terrain area, conspicuous landscape heterogeneity and difficult image acquisition and preprocessing. Supported by Land Cover Monitoring Project (CLCP) funded by Chinese Academy of Sciences, land cover product of Southwestern China in 2010 was mapped through an object-oriented method combined with the decision tree rules, and the land cover products in 2000 and 2005 were obtained by the change detection. The validation shows that the overall accuracies of the primary and secondary classes reach 95.09% and 90.34% respectively. Taking Sichuan province and Tibet autonomous region as case, the CLCP product analysis indicates that a total of 14,580 km² and 8,174 km² area, accounting for 3.04% and 0.68% of the region respectively, had changed in the last 20 years. The main driving forces including climate change, human activities and natural disasters are also discussed.