Figures & data
Figure 1. Arable land distribution in North Korea with DEM as background. Province boundaries, field survey points, and validation site are also illustrated. For full color versions of the figures in this paper, please see the online version.
Figure 2. Crop calendar in North Korea and Liaoning Province of China.
Figure 3. Field survey in 2013 and Google Earth crop points. NK and LN represents North Korea and Liaoning province, respectively. Landsat image as background was acquired on 30 September 2013, RGB: NIR/red/green.
Table 1. Geographical coordinates and collecting date of the photos obtained from Google Earth Engine for North Korea.
Table 2. Planting acreage of the three major crops in North Korea, 2004–2014 (1000 ha).
Table 3. Six features included in MODIS phenology product.
Figure 4. Signatures characterizing an NDVI profile.
Table 4. Ground survey and Google Earth points covered by Landsat scene.
Figure 5. Smoothed NDVI profiles for ground samples in Liaoning Province. The numbers of samples are 120, 90, and 75 for maize, rice, and soybean, respectively.
Figure 6. Averaged NDVI profiles for each type of crops in North Korea and Liaoning Province.
Figure 7. (a–f) Histograms of the selected phenology features.
Table 5. Averages of the phenological features and their tolerance difference for each crop.
Figure 8. Spatial distribution of crops in North Korea from 2004 to 2014; red circles mark areas with great increase of soybean since 2011.
Figure 9. Crop acreage derived from MODIScrop maps.
Table 6. National scale crop acreage estimated from MODIScrop and reported in FAO statistic data, and their relative difference.
Figure 10. (a–c) Comparison of crop acreage derived from MODIS classification and the FAO statistical data at the national scale.
Table 7. Regional scale crop acreage estimated from MODIScrop and LScrop, and their relative difference.
Table 8. Overall accuracy (OA) and omission error/commission error (OE/CE) of MODIScrop in 2008, 2013, and 2014.
Figure 11. The performance of each crop in the OE/CE space with the Pareto boundaries provided at each reference year.
