Spatial-temporal Changes of Cropland in China for the Past10Years Based on Remote Sensing

Based on remote sensing and geographic information system, the changes of spatial distribution of cropland for the past 10 years in China are studied. The results show that the total area of cropland is increasing while the cropland in the southeastern part of China is decreasing, whereas the cropland in Northeast China and the arid and semiarid areas of China is expanding. The ecological and environmental quality of reclaimed and lost cropland is evaluated. Thirteen patterns of the spatial changes of cropland in China can be classified into 13 areas correspondingly. Each area has its cropland transformation characteristics. In each area, the patterns of the former five years and the latter five years are similar on the whole. But the quantity of changed cropland is different. In some areas, the croplands increase or remain unchanged in the former five years but decrease in the latter five years, and vice versa. The nationwide warming is in better coincidence with the northward shifting of the paddy fields in China; at the same time, the drought in Northwest China causes the coexistence of considerable scale of reclamation and loss of cropland. The economic development induced rapid urbanization process is closely related with the occupancy of vast area of cropland for construction. Although the total food production is stable, the more area of cropland in a province is lost, the more production drop occurs.