Conference presentation
Open access

Contribution of citizen science in flood hazard assessment

Presented atWMO workshop Innovation in Hydrometry – from ideas to operation, Geneva (Switzerland), 4-5 December
Publication date2017

Floods are known as the most frequent events worldwide, which are caused by natural and human factors. The series of floods occurring this summer in the Unites States of America (Houston), in the Philippines (Luzon Island), or in Switzerland (Zofingen) showed how floods can affect our modern societies. One of the key elements necessary for developing efficient strategies for hazard and risk mitigation is flood hazard mapping. Flood hazard is currently assessed by combining data coming from hydro-meteorological stations, remote sensing and hydrological/hydraulic modelling. Despite the numerous advantages of these tools, they may also present some limitations depending on the area under investigation. With this work, we present the contribution of citizen science in flood hazard analysis in a pilot study: a suburban area of Dakar, Senegal, where flooding has emerged lately as a major threat for its population. This area is characterized by a) a lack of a record of past events, b) poor coverage of hydro-meteorological stations, c) no regular update of basic data, such as topography, and d) some issues with satellite images (e.g. alteration of the quality of the scene or even its cost). Using a combination of citizen science techniques, such as participatory mapping, participatory GIS and social media, the citizens of the area are providing different thematic spatial data such as rainfall intensity, flow direction, extent estimation of the water depth of past flood events (Sy et al 2016). Contributors collected daily average rainfall through simple devices implemented in this regard, and posted the information in a dedicated Facebook page (https://www.facebook.com/xeex.meude). Then, by working with 246 people, including 82 neighbourhood chiefs, we disentangled, through participatory mapping, the explicit memory of the local population on spatial extent and water levels of past flood events. The participatory approach was also applied to retrieve the hydrographic network, focusing particularly on the flow direction. These promising results show how citizen science through participatory mapping, participatory GIS and social media can help capturing information necessary for flood hazard analysis, in particular for areas where no instrumental network is available and financial resources are scarce. References [1] Sy B., Frischknecht C., Dao H., Giuliani G., Consuegra D., Wade S. and Kêdowidé C. Participatory approach for flood risk assessment: the case of Yeumbeul Nord (YN), Dakar, Senegal, in WIT Transactions on the Built Environment, 2016, 165

  • Flood hazard
  • Citizen science
Citation (ISO format)
SY, Bocar et al. Contribution of citizen science in flood hazard assessment. In: WMO workshop Innovation in Hydrometry – from ideas to operation. Geneva (Switzerland). 2017.
Main files (1)
  • PID : unige:102441

Technical informations

Creation02/14/2018 3:46:00 PM
First validation02/14/2018 3:46:00 PM
Update time03/15/2023 7:53:15 AM
Status update03/15/2023 7:53:15 AM
Last indexation05/02/2024 8:00:26 PM
All rights reserved by Archive ouverte UNIGE and the University of GenevaunigeBlack