Assessing flood exposure in informal districts: a case study of Bujumbura, Burundi

Abstract

In most sub-Saharan African cities, urban growth is generally unplanned. Recent research studies analysed the vulnerability of these settlements to natural hazards and drew out challenges related to lack of integrated actions from stakeholders, inefficiency in housing structures and vulnerability of poorer households. But, we still need to document implications of urban growth management relying on status quo and regularization, in terms of worsening exposure to flooding. Filling the gap, this paper focuses on exposure to flooding of informal districts of Bujumbura City, Burundi. Results show that the zones where the town is expanding are the most exposed. Our aim is to alert inhabitants and urban planners, so that a proactive approach could be adopted. This is deemed to insure that specificities of every urban site are considered during an integrated urban planning, including flood mitigation in exposed sites in Bujumbura, and also in other cities facing the same issue of uncontrolled urbanization.

Keywords:

• informal urbanization
• flood exposure assessment
• decision support
• urban planning
• Bujumbura
• sub-Saharan African cities

Acknowledgements

The authors would like to thank Burundi Geographical Institute (IGEBU) from whom they obtained data about rainfall information; it was a corner stone for calculations of river discharges calculations. The authors also thank the U.S. Army Corps of Engineers who developed HEC-RAS and made it open access for researchers; the software was among the key tools for our study. Lastly, the authors thank the U.S. Geological Survey for providing them with DEM of the study area, essential as substratum of the analyses.

Additional information

Notes on contributors

Gamaliel Kubwarugira

Gamaliel Kubwarugira is an Architect and Urban Planner graduate from the University of Tizi Ouzou, Algeria. Gamaliel is at present a PhD student at Sultan Moulay Slimane University of Beni Mellal, Morocco and a member of the Team for Research on Cities and Regionalisation in Morocco. Gamaliel’s research topics are urban growth management, urban risks assessment, participatory urban development, urban planning and resilience to adverse effects of climate change.

Mohamed Mayoussi

Professor Mohammed Mayoussi earned a PhD in Human Geography in 2003, Mohammed V University in Rabat. He is currently a researcher at Sultan Moulay Slimane University, Morocco. He is the director of the Team for Research on Cities and Regionalisation in Morocco. At the same time, he coordinates PhD training in urban growth and city planning. Mohammed Mayoussi is the Vice Dean of Research and Cooperation, Faculty of Arts and Humanities of Beni Mellal, Sultan Moulay Slimane University, Morocco.

Yahia El Khalki

Professor Yahia El Khalki is a researcher at the Faculty of Arts and Humanities of Beni Mellal, Sultan Moulay Slimane University, Morocco. Yahia is also the director of the Laboratory for Research on Dynamics of Landscape, Risk and Heritage. Yahia followed studies in Morocco until the licenseand went to France to have the master’s and PhD. Yahia’s interests are:

• Water resources and climate change in arid and semi-arid areas,

• Hydrological karst and impacts of human activity on geosystem karstics,

• Geomorphosites: inventory, assessment and valuation for purposes of geotourism in the perspective of the concept of ‘Cultural Landscape integrated’,

• Urban and rural landscapes: dynamics and sustainable development.