Multidisciplinary reconstruction of the flood episode of September 1793

Climate variability conditioned by the effects of climate change justifies the study of past periods in order to identify and characterise episodes of high severity and low frequency. The increase in the irregularity of the precipitation regime in some regions justifies the study of these events for a better assessment of their occurrence in the immediate future. In this regard, the climatic framework of the Maldà Oscillation (1760-1800) offers hydrometeorological anomalies of low frequency and high severity, especially in the dimension of catastrophic floods. One of the episodes that occurred in this period affected the region of the present-day Valencian Community, on the eastern coast of the Iberian Peninsula, between 6 and 8 September 1793.The aim of this work is to reconstruct, in as much detail as possible, the meteorological and hydrological behaviour of an extraordinary rainfall event. At the same time, it also aims to reconstruct the impacts caused on human activity. In order to achieve this objective, data from old instrumental meteorological observation and the result of an extensive collection of information from historical documentary sources are used. Although the meteorological data are scarce, they allow the synoptic characterisation of the episode. The hydrological approach of the episode is only qualitative, but it allows the identification of the affected river basins and the occurrence of river floods and overflows. The social impacts of the episode are significant and occurred due to the exceptional nature of the episode. For example, the overflowing of the top of a hydraulic dam built at the end of the 16th century (Tibi dam, 43 metres above the river course). Despite the presence of hydraulic infrastructures that were able to control the floods, there were numerous catastrophic damages that are represented in a detailed thematic cartography. During 3 days of flooding, 7 river basins belonging to the Júcar and Segura hydrographic demarcations were affected, with 11 towns and villages suffering catastrophic damages. Likewise, the social response to these events is analyzed, basically characterized by the celebration of religious ceremonies.