Global Grid of Probabilities of Urban Expansion to 2030

The Global Grid of Probabilities of Urban Expansion to 2030 presents spatially explicit probabilistic forecasts of global urban land cover change from 2000 to 2030 at a 2.5 arc-minute resolution. For each grid cell that is non-urban in 2000, a Monte-Carlo model assigned a probability of becoming urban by the year 2030. The authors first extracted urban extent circa 2000 from the NASA MODIS Land Cover Type Product Version 5, which provides a conservative estimate of global urban land cover. The authors then used population densities from the Global Rural-Urban Mapping Project, Version 1 (GRUMPv1) to create the population density driver map. They estimated the amount of new urban land in each United Nations region by 2030 in a Monte-Carlo fashion based on present empirical distribution of regional urban population densities and probability density functions of projected regional population and GDP values for 2030. To facilitate integration with other data products, CIESIN reprojected the data from Goode's Homolosine to Geographic WGS84 projection.

《至2030年全球城市扩张概率网格》展示了从2000年至2030年全球城市土地利用变化的空间显式概率预测，分辨率达到2.5弧分。对于2000年非城市区域的每个网格单元，通过蒙特卡洛模型分配了到2030年成为城市区域的概率。作者首先从NASA MODIS土地覆盖类型产品第五版中提取了约2000年的城市范围，该产品提供了全球城市土地利用的保守估计。随后，作者利用全球农村-城市映射项目第一版（GRUMPv1）中的人口密度数据创建人口密度驱动图。基于当前区域城市人口密度的经验分布以及2030年预测区域人口和GDP值的概率密度函数，以蒙特卡洛方法估计了至2030年各联合国区域新增城市土地的量。为了便于与其他数据产品集成，CIESIN将数据从Goode的Homolosine投影重新投影到地理WGS84投影。