William Evans



Mr. Evans, based in Charlottesville, Virginia, is a Project Manager for the Humanitarian OpenStreetMap team. Mr. Evans plans to use the resources from the fellowship to carry out a pilot project in Dar es Salaam, Tanzania using a dual frequency GPS sensor to create highly accurate surveys in an informal settlement. This will empower a local community in Tanzania, but also could be a pathway for people around the world without legal titles to their land. At the same time, he hopes to spark the conversation about the ethical issues involved in using geospatial technology, with a specific focus on land administration. Three issues he hopes to explore are how land rights can protect citizens against expulsion, how they can give residents the ability to access credit, and how this connects with governance as it can be a primary means of taxation.

EthicalGEO Project Results

Mr. William Perry Evans, a manager with Humanitarian OpenStreetMap Team (HOT) in Tanzania, with support from the American Geographical Society and Omidyar Network, sought to answer one primary question—how can we make land rights accessible to the urban poor in Tanzania, with an eye to creating a model for the rest of the developing world? Our answer, as you will read in the report, is community cadastres.

This interactive map below shows a comparative analysis between cadastral data obtained using an inexpensive u-bloxSED-F9P GNSS receiver ($200), and a more expensive, SOUTH S86 RTK GNSS Surveying System ($7000) used by a professional surveying company. The visualization shows clearly how these 20 plots practically overlap – the more scientifically robust evidence comes from using Precise Point Positioning, where we found extremely high levels of position accuracy (under 5 centimeters).