Understanding the Link Between Geology and Cholera in Harare

Cholera transmission is usually thought of in terms of the human or social factors that contribute to its spread. However, physical factors relating to underlying geology, topography and drainage of an area may be equally important. In recent years, cholera has become a perennial issue is Harare. In some parts of the city, contaminated water has been found to seep into the underground aquifers making boreholes in some areas unsafe to drink from. The risk of this occurring depends how easily surface water infiltrates and becomes part of the underground aquifer systems and how easily contaminated water can spread once in an aquifer.

Using GIS and a Multi Criteria Decision Analysis we mapped and weighted geological/physical factors related to cholera risk in Harare and produced a risk map of the city showing which areas were particularly vulnerable to cholera.

Client: The World Bank