Estimation of Grain Crop Yields after Returning the Illegal Nurseries and Orchards to Cultivated Land in the Yangtze River Delta Region
The purpose of this study is to develop a new remote sensing method to assess the area of cultivated land illegally converted to nurseries and orchards in the Yangtze River Delta region of China over the past 40 years (1980–2020), and then estimate the increase in grain yield based on this area. Our result showed that 2.23 × 104 km2 of cultivated land was reduced by 11.8% over the past 40 years. About 14,521.40 km2 of cultivated land was converted to nursery and orchard from 1980 to 2020. The conversion area was unevenly distributed among different administrative regions.