Method for fluvial and pluvial flood risk assessment in rural settlements

Maurizio Tiepolo, Elena Belcore, Sarah Braccio, Souradji Issa, Giovanni Massazza, Maurizio Rosso, Vieri Tarchiani
Published in: MethodsX, Volume 8, 2021
Date: July 19, 2021


Flood risk assessments in the Global South have increased since the adoption of the United Nations Sendai
Framework for Disaster Risk Reduction 2015–2030. However, they often fail to meet disaster risk reduction needs
at the local scale, because they typically consider only one hazard (fluvial or pluvial floods). Furthermore, hazard
and exposure are considered as stationary conditions, flood-prone assets are rarely identified, risk reduction
measures are not identified in detail for specific locations, and the convenience of reducing or accepting risk
is not evaluated. This paper describes a flood risk assessment method that is innovative in that it considers three
hazard types (backwater, fluvial, and pluvial floods) and multiple risk scenarios; it uses orthophotos generated
from images captured by an unmanned aerial vehicle and very high-resolution satellite images, and it involves
communities in risk assessment. The method was applied to four rural settlements along the Sirba River, Niger.
The assessment identifies the benefit of reducing risk in monetary terms, as well as the intangible benefits that
reducing risk could generate, and it detects opportunities that flooding offers for rural development. The method
can be replicated in all contexts where decision-making support is needed for flood risk assessment planning.