Global high-resolution estimation of cropland suitability and its comparative analysis to actual cropland distribution

Abstract

Global 500-m (18-arcsec) resolution cropland suitability was estimated using recently developed high-resolution global cropland data and a digital elevation model. The high-resolution estimation more precisely represented topographical constraints to agriculture that were not adequately reflected in previous low-resolution estimates. It also successfully suppressed the overestimation of cropland suitability on areas with steep slopes. Furthermore, the distinction of rainfed and irrigated cropland removed suitability overestimation induced by human agricultural intervention and enabled more natural and realistic estimation of cropland suitability. The comparative analysis between the estimated land suitability and actual cropland distribution revealed that, if only natural condition is considered, it is possible to expand cropland area by 9.25 million km², which is more than needed in the future while socio-economic factors controlling cropland suitability should be considered for more practical assessment. The newly developed highest-resolution cropland suitability map is expected to contribute to solving upcoming water, energy, and food issues, by integrating with water resource models and biomass studies.