Flood mapping for disaster risk reduction: Obtaining high-resolution imagery to map and model flood risks in Dar es Salaam (Tanzania)

Drones in Humanitarian Action - Case Study No.1

This case study highlights the role drones can play in providing high-resolution and up-to-date imagery that is essential to the development of exposure maps and for modelling flood risks in Dar es Salaam, Tanzania. In fact, Over 70 per cent of the people live in informal, unplanned settlements with inadequate infrastructure. In addition, heavy rainfalls twice a year result in significant flood risks.

Local authorities see the maps as starting points in the evaluation of areas subject to improvements, and for the response to flooding and related disease outbreaks. The detailed ward maps allow public health officials to identify specific houses with known cholera patients in case of an outbreak allowing for much more efficient response through targeted dispatch of medical care. The exposure maps that include up-to-date buildings and infrastructure now enable planners to identify places that get flooded and to pinpoint where drainage systems need to be installed. This new capacity has even helped the city council acquire funding from the central government to install drainage systems in vulnerable places.