Error matrix of the combination model (20%, 20%).

Note: 1) Land cover types with number 1 (i.e. Cropland1, Forest1, Grassland1, Water1, Residential and construction land1, and Bareland1 ) stand for land cover results of the visual interpretation; Land cover types with number 2 stand for land cover results of Automatic classification. 2) For better quantitative assessment, absolute values (pixel number) were converted to percentage values in each error matrix. 3) For automatic classification result, overall accuracy = 37.7%, KC = 0.149, sample size = 8,658,588.