Population and housing censuses are typically the largest peacetime operation that governments engage in, requiring substantial financial and human resources. The rapid advances in geospatial data, algorithms and computing power are offering opportunities for both improved accuracy and efficiency throughout the census process. One key area is in the preparation for the census enumeration with the delineation of enumeration areas (EAs). EAs are areas that can be canvassed by a single data collector while undertaking a survey or census and mapping accurate EA parameters is vital to efficiently survey a country’s population. Existing EAs are however often incomplete, outdated or missing and developing new boundaries can be labour and cost intensive.

WorldPop’s preEA tool aims to overcome some of these difficulties through the use of infrastructure data, satellite-derived feature mapping and WorldPop’s gridded population datasets. By using features such as roads and rivers that can be easily recognised by teams on the ground, the tool automatically delineates EAs that meet criteria set by census and survey planners, including estimated population sizes in each unit. The tool has now been tested and implemented in multiple countries around the World for census planning and the construction of new sample frames.