Institut de Recherche pour
             le Développement
             Real-time urban flood risk data
             via cellphone network analysis




             In drought-prone regions like the Sahel, a sun-drenched region of Northern Africa that runs from the
             Atlantic Ocean to the Red Sea, the lack of water is a harsh and inescapable reality for millions. Increasingly
             dangerous, however, is the sudden deluge of the very same precious resource. Extreme weather events are
             increasing in frequency and intensity with climate change, with floods now impacting typically drought-
             prone regions like the Sahel. Fast population growth, unplanned urbanization, and the lack of adequate
             wastewater and drainage networks worsen flood risks for millions.
CONTEXT




             The ability to monitor rainfall with sufficient precision is vital to anticipate these risks, as well as to provide
             information and tools for the authorities to take timely, potentially life-saving decisions. In high income
             countries, rainfall and urban/rural flood monitoring is provided by weather and water agencies with well-
             developed observation systems like radar. However, this expensive and high-maintenance equipment is
             often out of reach for low-income countries.

             To provide an alternative, innovative, and affordable solution, a team at the Institut de Recherche pour le
             Développement tested an urban flood protection system in Burkina Faso that measures rainfall via the loss
             of cellular network signals.




                                                                   $
HIGHLIGHTS




                     Created awareness of                   Validated this cost                  Brought together
                      the potential use of               effective and innovative              cellular providers to
                    mobile phone networks                solution for monitoring              help bring the method
                    to identify and quantify               rainfall in the city of             to scale in the Sahel
                        urban flood risk.                     Ouagadougou.                      and other regions.
              The Institut de Recherche pour le Développement team and other international collaborators worked to create a
              cost-effective alternative to weather radar using mobile telecommunication networks. This method exploits radio
              waves attenuation caused by rain. Based on the loss of signal on the cellular network, rainfall can be accurately
              monitored throughout the network. In Africa, where the mobile phone network is dense and growing, this method
APPROACH




              offers an unprecedented potential for accurate and real-time rainfall monitoring, especially in urban areas where the
              network is extremely dense.
              With this new technique, a hydrological model was developed for Ouagadougou city to provide a Flood Early
              Warning System for decision makers. In collaboration with local weather services and a cellular operators, the
              team demonstrated and quantified the interest and practical advantages of the new monitoring method. Two
              mobile operators (one in Burkina Faso, and one in Niger) agreed to provide free data to the project in two major
              African cities.




             “Flooding has become a major problem in Burkina Faso. As director of Civil Protection Services,
                 taking timely decisions to ensure the safety of the population is a serious responsibility.”
                   - Colonel Lazare Yago, General Director of Civil Protection Services in Ouagadougou



              In the near future, the team will finalize the operationalization of the tools and, together with local authorities, will
NEXT STEPS




              quantify their practical impact on population through better and more timely decision making. The team will also
              continue investigating and developing potential collaborations to help scale the concept to other cities in the Sahel
              and beyond.
              Another upcoming challenge is to ensure acceptance of the warnings by the population in order to maximize the
              effective impact of flood early warnings for improved resilience. Further analysis and interaction with population is
              among the objectives for the project’s next phase.




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