Comparison of relative uniformity between GLOBCOVER andMODIS land cover data sets

The information on land cover at national scales is critical for addressing a range of problems, including climate change, biodiversity conservation, ecosystem assessment and environmental modeling. In this study, two of the most highly resolution global land cover products were compared: GLOBCOVER and MODIS Collection5, with resolution 300 m and 500 m, respectively, by using the relative comparison analysis to identify areas of spatial agreement and disagreement in national, regional and category levels. The result show that: there is a consistency in national scale, but there remain substantial inconsistencies and discrepancies in subarea, especially in Northeast and Southwest zone; Two products have a serious confusion between Forest/mixed forest, Woodland/shrub land, Cropland and Grassland, especially the Crop land between other categories; the gap for overall accuracy and kappa coefficient form national scale to subarea scale is conspicuous, the value vary from 27.01% to 56.35% for overall accuracy; the range vary from 16.57% to 47.09% for kappa coefficient. Northeast zone has the best consistency with the national scale in general, but Sichuan Basin has the worst consistency with the nation scale. MODIS has a well homogeneous category than GLOBCOVER, the relation between the difference value of homogeneous category and category consistency present an obvious negative correlation, the R2 is 0.724. The results can provide a reference for land cover research.