Mapping Cholera Deaths
around the Broad Street
Pump in London (1854)
Columbia University
Fall 2022
John Snow
An early form of investigative mapping, John Snow’s Inquiry into the broad street water pump as the source of London’s Cholera outbreak has become an influential piece of map history.

A remapping of the Cholera data from the original map through methods of spatial statistics and clustering analyses brings to light new findings. Using GIS software, it was determined that the mean center of the Cholera outbreak was only 27.5 meters from the Broad Street Pump- in line with Snow's initial findings

A majority of deaths, occurred within one standard deviation from the Broad Street Water Pump. Finally, to test local clustering, the Getis-Ord Gi* test was conducted. This found that hot spots were indeed clustered around the infamous street pump.
Read the full report here
ArcGIS Pro, Adobe Illustrator
Spatial Statistics, Spatial Clustering, Getis-Ord Gi* Test