Crop Area Assessment Using Remote Sensing on the North China Plain

Crop acreage assessment is of particular importance in China where total crop land area is shrinking following the urbanization, directly threatening the policy of grain self-sufficiency. This study demonstrated the application potential of remote sensing to estimate large crop areas on the North China Plain (NCP). The cropping pattern in this plain comprises two growth seasons per year. The harvest of winter wheat is usually followed by the plantation of maize. Two mapping approaches were applied. One consists of the hard classification of multi-temporal high resolution images. Whereas LANDSAT TM data were classically used, the appearance of high resolution sensors with large swath widths such as IRS-P6 AWiFS provides data appropriate for crop mapping on much larger areas. The second approach uses sub-pixel classification of medium or low resolution imagery with the aim to improve the cost-efficiency of assessment. In this study, the sub-pixel classification of SPOT-VEGETATION data was calibrated using the hard classification products of two TM frames of 2005. On the other hand, the classification of two AWiFS scenes of 2007 led to a crop area estimation for nearly the whole study area. * Contact: [email protected]