Reconstituting past flood events : the contribution of citizen science

Sy, Bocar (Department of Earth Sciences, Faculty of Science, University of Geneva, Geneva, Switzerland) ; Frischknecht, Corine (Department of Earth Sciences, Faculty of Science, University of Geneva, Geneva, Switzerland) ; Dao, Hy (Department of Geography and Environment, Geneva School of Social Sciences, University of Geneva, Geneva, Switzerland ; Institute for Environmental Sciences, University of Geneva, Geneva, Switzerland) ; Consuegra, David (Department of Earth Sciences, Faculty of Science, University of Geneva, Geneva, Switzerland ; School of Management and Engineering Vaud, HES-SO // University of Applied Sciences Western Switzerland) ; Giuliani, Gregory (Institute for Environmental Sciences, University of Geneva, Geneva, Switzerland)

Information gathered on past flood events is essential for understanding and assessing flood hazards. In this study, we present how citizen science can help to retrieve this information, particularly in areas with scarce or no authoritative measurements of past events. The case study is located in Yeumbeul North (YN), Senegal, where flood impacts represent a growing concern for the local community. This area lacks authoritative records on flood extent and water depth as well as information on the chain of causative factors. We developed a framework using two techniques to retrieve information on past flood events by involving two groups of citizens who were present during the floods. The first technique targeted the part of the citizens' memory that records information on events, recalled through narratives, whereas the second technique focused on scaling past flood event intensities using different parts of the witnesses' bodies. These techniques were used for three events that occurred in 2005, 2009 and 2012. They proved complementary by providing quantitative information on flood extents and water depths and by revealing factors that may have contributed to all three flood events.


Article Type:
scientifique
Faculty:
Ingénierie et Architecture
School:
HEIG-VD
Institute:
insit - Institut d’ingénierie du territoire
Date:
2020-01
Pagination:
14 p.
Published in:
Hydrology and Earth System Sciences
Numeration (vol. no.):
2020, vol. 24, no. 1, pp- 61-74
DOI:
ISSN:
1607-7938
Appears in Collection:



 Record created 2020-01-17, last modified 2020-01-21

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