Gridded Population of the World, Version 4 (GPWv4): Population Density Adjusted to Match 2015 Revision of UN WPP Country Totals

Gridded Population of the World, Version 4 (GPWv4) Population Density Adjusted to Match 2015 Revision of UN WPP Country Totals consists of estimates of human population density, based on counts consistent with national censuses and population registers with respect to relative spatial distribution, but adjusted to match the 2015 Revision of UN World Population Prospects country totals for the years 2000, 2005, 2010, 2015, and 2020. A proportional allocation gridding algorithm, utilizing approximately 12.5 million national and sub-national administrative units, is used to assign population values to 30 arc-second (~1 km) grid cells. The population density grids are derived by dividing the population count grids by the land area grids. The pixel values represent persons per square kilometer.世界栅格人口第四版（GPWv4）：匹配联合国世界人口展望（UN World Population Prospects, WPP）2015修订版国家总人口数据的人口密度数据集，包含人口密度估算值。该数据集的人口计数基础与各国人口普查及人口登记数据的相对空间分布保持一致，并针对2000年、2005年、2010年、2015年及2020年五个年份，调整至匹配联合国世界人口展望2015修订版的国家总人口数据。本数据集采用比例分配栅格化算法，依托约1250万个国家级及次级行政区单元，将人口数值赋值至30角秒（约1千米）的栅格单元中。人口密度栅格通过将人口计数栅格除以土地面积栅格计算得到，栅格像素值代表每平方千米的人口数量。