• The methodology analyses precipitation data since 1901 and shows a decreasing trend in rainfall in Spain

 

  • Precipitation zones in the Iberian Peninsula are influenced by geographically distant climate events, such as El Niño

Since the early 20th century, precipitation has been decreasing in three of the five identified zones in Spain. | Pixabay

A recent study by the Institute of Environmental Assessment and Water Research (IDAEA-CSIC) and the University of Barcelona has analysed over a century of precipitation data to identify the areas with the highest rainfall in Europe, Spain, and Catalonia. Using statistical methods, researchers have determined that Spain has five precipitation zones, which show a trend towards reduction. Additionally, the study reveals that distant climate phenomena, such as El Niño in the Pacific or meteorological patterns in Antarctica, significantly influence rainfall in Spain.

Published in the International Journal of Climatology, the study employs a novel methodological approach, applying multivariate statistical analysis in multiple phases to capture the complexity of the relationships between rainfall and the diversity of climate indices at different spatial and temporal scales.

“The results indicate that precipitation is decreasing in three of the five identified zones: the southwest of Spain and the Mediterranean slope, particularly in Catalonia, confirming a trend towards worsening droughts in the future,” highlights Stefan Platikanov, a researcher at IDAEA-CSIC and the study’s first author.

According to Romà Tauler, IDAEA researcher and the study’s lead author, the methodology helps improve the prediction and management of risks associated with extreme weather events, such as meteorological droughts, which increase the likelihood of severe flooding.

The research has shown that “up to twenty teleconnections—that is, atmospheric and oceanic behaviour patterns linking distant regions—influence precipitation in Europe, Spain, and Catalonia, territories with great geographical diversity”, states Javier Martin-Vide, Professor of Physical Geography at the University of Barcelona and author of the study.

Of the 22 circulation patterns compiled and analysed, El Niño and other Pacific patterns show a strong correlation with precipitation in Europe and Spain. This finding demonstrates that distant climate phenomena also affect precipitation, highlighting the importance of global factors in regional studies.

“The value of this study also lies in refining the resolution to a small geographical scale, at the county level. It is crucial to understand climate trends at an intra-regional level, not just the global trends provided by climate models”, emphasises Belén Martrat, a researcher at IDAEA-CSIC and author of the study.

The authors highlight the lack of long precipitation records in key regions of Catalonia, especially in mountain areas—important sentinels of water reserves—such as Pallars Sobirà, Noguera, and Pla d’Urgell. There is also a shortage of data series in populated areas vulnerable to flooding, such as Tarragonès and Baix Penedès, as well as in regions relevant for their proximity to seismic and volcanic activity, such as Garrotxa.

This research provides a solid scientific basis for climate decision-making. Specifically, it supports the identification of vulnerable areas, water resource planning, risk management and early warning systems, and the development of agricultural policies better adapted to climate change.

Stefan Platikanov, Jordi F. Lopez, Belen Martrat, Javier Martin-Vide, Roma Tauler. Temporal and Spatial Relationships Between Climatic Indices and Precipitation Zones in Europe, Spain and Catalonia. International Journal of Climatology, 2025; 45: e8699. DOI: 10.1002/joc.8699