@article{fdi:010090077,
  title = {{C}hanges in {M}editerranean flood processes and seasonality},
  author = {{T}ramblay, {Y}ves and {A}rnaud, {P}. and {A}rtigue, {G}. and {L}ang, {M}. and {P}aquet, {E}. and {N}eppel, {L}. and {S}auquet, {E}.},
  editor = {},
  language = {{ENG}},
  abstract = {{F}loods are a major natural hazard in the {M}editerranean region, causing deaths and extensive damages. {R}ecent studies have shown that intense rainfallevents are becoming more extreme in this region but, paradoxically, without leading to an increase in the severity of floods. {C}onsequently, it isimportant to understand how flood events are changing to explain this absence of trends in flood magnitude despite increased rainfall extremes. {A}database of 98 stations in southern {F}rance with an average record of 50 years of daily river discharge data between 1959 and 2021 wasconsidered, together with a high-resolution reanalysis product providing precipitation and simulated soil moisture and a classification of weatherpatterns associated with rainfall events over {F}rance. {F}lood events, corresponding to an average occurrence of 1 event per year (5317 events intotal), were extracted and classified into excess-rainfall, short-rainfall, and long-rainfall event types. {S}everal flood event characteristics havebeen also analyzed: flood event durations, base flow contribution to floods, runoff coefficient, total and maximum event rainfall, and antecedentsoil moisture. {T}he evolution through time of these flood event characteristics and seasonality was analyzed. {R}esults indicated that, in mostbasins, floods tend to occur earlier during the year, the mean flood date being, on average, advanced by 1 month between 1959-1990 and1991-2021. {T}his seasonal shift could be attributed to the increased frequency of southern-circulation weather types during spring and summer. {A}nincrease in total and extreme-event precipitation has been observed, associated with a decrease of antecedent soil moisture before rainfallevents. {T}he majority of flood events are associated with excess rainfall on saturated soils, but their relative proportion is decreasing over time,notably in spring, with a concurrent increased frequency of short rain floods. {F}or most basins there is a positive correlation between antecedentsoil moisture and flood event runoff coefficients that is remaining stable over time, with dryer soils producing less runoff and a lowercontribution of base flow to floods. {I}n a context of increasing aridity, this relationship is the likely cause of the absence of trends in floodmagnitudes observed in this region and the change of event types. {T}hese changes in flood characteristics are quite homogeneous over the domainstudied, suggesting that they are rather linked to the evolution of the regional climate than to catchment characteristics. {C}onsequently, thisstudy shows that even in the absence of trends, flood properties may change over time, and these changes need to be accounted for when analyzing thelong-term evolution of flood hazards.},
  keywords = {{ZONE} {MEDITERRANEENNE}},
  booktitle = {},
  journal = {{H}ydrology and {E}arth {S}ystem {S}ciences},
  volume = {27},
  numero = {15},
  pages = {2973--2987},
  ISSN = {1027-5606},
  year = {2023},
  DOI = {10.5194/hess-27-2973-2023},
  URL = {https://www.documentation.ird.fr/hor/fdi:010090077},
}