Drought behaviour in Barcelona from its instrumental precipitation series (1786-2022)

The current climate change scenario increases the concern for water resource management and for the increase in the frequency of droughts in the Mediterranean region. This work proposes the analysis of the instrumental precipitation series of the city of Barcelona (1786-2022), which extends from the end of the Little Ice Age to the current climatic period. This series, due to its temporal length, constitutes a continuous scenario of pluviometric information that allows the identification and analysis of the periods in which the most severe droughts occur.

This work is organized following two main objectives. The first objective consists on the analysis of the values of this precipitation series using different statistical techniques, including drought indices. The second objective is the evaluation of the severity of the most significant drought events that appear in the instrumental precipitation series of Barcelona.

To achieve these objectives, the methodologies used in this work consist on the application of some statistical techniques on the instrumental precipitation series, such as the detection of its breaking points. At the same time, this work proposes the application of different drought indices as the SPI index and the SPEI index on the entire instrumental precipitation series of Barcelona (1786-2022). The use of these methodologies allows the comparison between the different droughts included in the instrumental series. These also allow distinguishing the most relevant droughts according to their severity. Two significant examples of the most severe droughts are the ones of the first third of 19th century (1812-1825) and the droughts of the 21st century (1998-2008). We also want to determine the relevance of the current drought (2021-2022) in contrast to the overall instrumental series of precipitation of Barcelona.

Additionally to these methodologies and results, for the most significant droughts detected in the precipitation series, it is also proposed to use monthly barometric indices to characterise the general atmospheric circulation of those periods. It would have the aim to contrast the results on the instrumental precipitation series with the synoptic conditions that produce these droughts. This comparison also would help to determine if these conditions have changed over time, especially considering recent decades in the context of current climate change.