@article{fdi:010082298,
  title = {{R}ecent changes in hydroclimatic patterns over medium {N}iger river basins at the origin of the 2020 flood in {N}iamey ({N}iger)},
  author = {{M}assazza, {G}. and {B}acci, {M}. and {D}escroix, {L}uc and {I}brahim, {M}. {H}. and {F}iorillo, {E}. and {K}atiellou, {G}. {L}. and {P}anthou, {G}. and {P}ezzoli, {A}. and {R}osso, {M}. and {S}auzedde, {E}. and {T}erenziani, {A}. and {D}e {F}ilippis, {T}. and {R}occhi, {L}. and {B}urrone, {S}. and {T}iepolo, {M}. and {V}ischel, {T}. and {T}archiani, {V}.},
  editor = {},
  language = {{ENG}},
  abstract = {{N}iamey, the capital of {N}iger, is particularly prone to floods, since it is on the banks of the {N}iger {R}iver, which in its middle basin has two flood peaks: one in summer (the red flood) and one in winter (the black flood). {I}n 2020, the {N}iger {R}iver in {N}iamey reached its all-time highest levels following an abundant rainy season. {O}n the other hand, the floods in {N}iamey have been particularly frequent in the last decade, a symptom of a change in hydroclimatic behaviour already observed since the end of the great droughts of the 1970s and 1980s and which is identified with the name of {S}ahelian {P}aradox. {T}his study, starting from the analysis of the 2020 flood and from the update of the rating curve of the {N}iamey hydrometric station, analyses the rainfall-runoff relationship on the {S}ahelian basins of the {M}edium {N}iger {R}iver {B}asin ({MNRB}) that are at the origin of the local flood. {T}he comparative analysis of runoffs, annual maximum flows ({AMAX}) and runoff coefficients with various rainfall indices calculated on gridded datasets allowed to hydroclimatically characterise the last decade as a different period from the wet one before the drought, the dry one and the post-drought one. {C}ompared to the last one, the current period is characterised by a sustained increase in hydrological indicators ({AMAX} +27%) consistent with the increase in both the accumulation of precipitation (+11%) and the number (+51%) and magnitude (+54%) of extreme events in the {MNRB}. {F}urthermore, a greater concentration of rainfall and extremes (+78%) in {A}ugust contributes to reinforcing the red flood's positive anomalies (+2.23 st.dev in 2020). {T}he study indicates that under these conditions the frequency of extreme hydrological events in {N}iamey will tend to increase further also because of the concurrence of drivers such as river-bed silting and levee effects. {C}onsequently, the study concludes with the need for a comprehensive flood-risk assessment on the {N}iamey city that considers both recent hydroclimatic trends and urbanisation dynamics in flood zones hence defining the most appropriate risk-reduction strategies.},
  keywords = {{M}iddle {N}iger {R}iver {B}asin ; {N}iamey ; {S}ahel ; floods ; rating curves ; runoff ; coefficients ; early warning system ; flood risk ; levees ; hazard ; thresholds ; {CHIRPS} ; {T}erra{C}limate ; {NIGER} ; {NIAMEY} ; {ZONE} {SAHELIENNE} ; {NIGER} {BASSIN}},
  booktitle = {},
  journal = {{W}ater},
  volume = {13},
  numero = {12},
  pages = {1659 [39 ]},
  year = {2021},
  DOI = {10.3390/w13121659},
  URL = {https://www.documentation.ird.fr/hor/fdi:010082298},
}