[process] MapSPAM Derive Rural Population Density

"Then we derive rural population density (AggRurPopi) based on the assumption that if there is cropland within the 5 arcmin grids, then the population residing within the grids should be rural people."
Yu, Qiangyi; You, Liangzhi; Wood-Sichra, Ulrike; Ru, Yating; Joglekar, Alison K. B.; Fritz, Steffen et al. (2020): A cultivated planet in 2010 – Part 2: The global gridded agricultural-production maps. In: Earth Syst. Sci. Data 12 (4), S. 3545–3572. DOI: 10.5194/essd-12-3545-2020.