Floods in the Pyrenees: A global view through a regional database

Abstract

This paper shows the first systematic datasetof flood episodes referring to the entire Pyrenees massif,named PIRAGUA_flood, which covers the period 1981–2015 (available at http://hdl.handle.net/10261/270351, lastaccess: 21 July 2024). First, the structure of the database isdetailed so that it can be reproduced anywhere else in theworld, adapting to the specific nature of each situation. Subsequently,the paper addresses the spatial and temporal distributionof flood episodes and events (including trends) thataffected the Pyrenees regions of Spain (Catalonia, Aragon,Navarre, the Basque Country), France (Nouvelle-Aquitaine,Occitanie) and Andorra, as well as the massif as a whole,for a given period of time. In the case of the Spanish regions,it was also possible to analyse the compensation paymentsby the Spanish Insurance Compensation Consortiumand the number of deceased. The weather types associatedwith flood episodes were also classified based on sea levelpressure and 500 hPa geopotential height from ERA5. Theresults show 181 flood events and 154 fatalities, some ofwhich affected more than one region. In the Spanish part ofthe Pyrenees, between 1996 and 2015, there was a total compensationpayout amounting to EUR 142.5 million (2015).The eastern part of the area records more flood events thanthe western one, with Catalonia being the community thatregistered the highest number of events, followed by Andorraand Occitanie. Associated weather types are dominatedby the southern component flow over the Pyrenees region,with a talweg on the Iberian Peninsula and a depression inthe vicinity, either in the Atlantic or in the Mediterranean.In terms of the entire massif, there is a slight positive trendof 0.84 events per decade, driven by the evolution of ordinaryand extraordinary floods but not significant at 95 %. Ata regional level, flood behaviour is more heterogeneous, althoughnot significant for the most part. Nouvelle-Aquitaineis the only region that shows a positive and significant trendof 0.34 events per decade