The remaining eight classifications were aggregated into five categories (cropland, forest, grassland, urban land, and water) following the level I classification scheme developed by Anderson et al. (1976).
Consider now an AEZ in region r with n types of original land cover classifications and assume a portion of each type of land classification is already converted to cropland.
Post-classification differencing identified regions of cropland that had been converted to CRP.
Utilizing multi-seasonal Landsat thematic mapper imagery in an unsupervised classification technique, we produced highly accurate maps of cropland and grassland for 1987 and 1992 for Finney County, Kansas.
For example, even with clear implementation criteria, the identification of managed grassland in Canada is problematic with relatively low classification accuracy of 55, 58 and 69%, while in contrast, Canadian cropland has been mapped at 71, 82 and 93% accuracy for 1990, 2000 and 2010, respectively [22].
Nevertheless, the available information provided valuable discriminant contributions in land cover mapping (Maximum Likelihood Overall Accuracy ∼85%) with encouraging reliability on mixed forests, croplands, and no-vegetated floodplain patterns, whereas riparian vegetation and urban zones exhibited low classification accuracies.
We combined these data with georeferenced and temporally explicitly soil and water salinity information, in addition to relative elevation classifications, in order to examine the extent of winter fallows and low productivity rainfed cropland that could be irrigated by small-scale surface water pumps.
Two urbanization indices describing both speed and magnitude of urbanization were derived and ecosystem services were calculated with a valuation scheme adapted to the Chinese market based on the classification results from 1990 and 2010 for the predominant land cover classes affected by urbanization: forest, cropland, wetlands, water and aquaculture.
China has 104m hectares of cropland.
