Study of historical flood events on Spanish rivers using documentary data

Series of reconstructed historical floods are valuable sources of proxy data that can be utilized for the study of flooding fluctuations in the pre-instrumental period. In this work, the severity and frequency of historical flood events in different Spanish rivers are analysed using documentary evidence. The occurrence of floods in the past is analysed bearing in mind the basic topographical and hydrological characteristics of the rivers investigated, as well as the climatological causes of their flooding during the instrumental period. Flood frequency oscillations identified in the present work coincide in general terms with already detected oscillations in previous research for shorter number of chronologies. Analysis for events covering more than two basins shows a relatively small number of cases. Meanwhile, as the climatic context produces simultaneous increases in frequency, geographical characteristics provoke a limitation on the extension of flood impacts during every severe weather event.