Methodology:
This tool begins by importing the latest available data from WPDx for the given district. Next, it imports high resolution population maps of the district from ESRI’s Living Atlas. This provides an estimate of the number of people living within every 250m x 250m grid square in the district. The tool then draws a circle around all functional water points with a radius equal to the access distance provided. The value of the population grid squares within the access circle are set to 0, as all of the people within the access distance of a functioning water point have service. A circle is then drawn around each non-functional water point with a radius equal to the access distance provided. The values of all of the population grid squares within the circle of each water point are added together, providing a total number of people not otherwise served for each non-functional water point.
Limitations:
This analysis is based on the latest available data, and population estimates from ESRI. Any water points that have been broken, rehabilitated, or constructed for which the data is not in WPDx have not been included in this analysis. Additionally, household connections are not captured in WPDx. As such, non-functional water points near large urban areas may be recommended for rehabilitation although people around it are served by household connections.