Catalonia's soil saturated with water after the rains: ready for the next drought?

Recent rains have recharged forest soils in Catalonia and the rest of Spain. This invisible reserve is key to facing future droughts and reducing fire risk. New digital tools make it possible to follow the evolution of moisture across the territory in real time.

Heavy rainfall in recent weeks has transformed the subsoil of Catalonia and much of the peninsula. Forests, from the metropolitan area to the Pyrenees, now store an amount of water not seen for years. This recharge, although it goes unnoticed by people walking through Collserola or Montjuïc, is vital for the health of ecosystems and the region’s water security.

CREAF’s Forest Laboratory has extended the ForestDrought application across the country, making it possible to monitor drought, soil moisture and fire risk in real time. Alongside Meteoland, which provides daily weather data even in areas without stations, these tools open a digital window for observing how vegetation and aquifers fill with life after rainfall.

Experts insist that this soaked soil is an investment in the future. So-called “green water”, which remains retained in vegetation and underground, acts as a natural buffer against heatwaves and extreme droughts. “Blue water”, which flows towards rivers and reservoirs, has also reached unusually high levels, strengthening supply capacity for agriculture and industry.

However, not everything is an advantage. Saturated soil can destabilise slopes and cause landslides, a risk already causing concern in some mountainous areas. Even so, the priority remains to take advantage of this moment of abundance to reinforce the resilience of forests and water resources before the climate changes again.

The relationship between forests and the water cycle is closer than it may seem. When rainfall is constant but not torrential, forest soil absorbs much of the water, regulating river flow and keeping aquifers charged during dry months. This dynamic is key to enabling the city and its surroundings to withstand periods of drought without drastic restrictions.

ForestDrought, developed by CREAF, uses data from different meteorological services and cross-references it with information on the land and forest structure. This makes it possible to estimate vegetation water stress and the moisture of combustible material, two decisive factors in anticipating forest fires. Meteoland’s update, for its part, makes it possible to obtain detailed weather forecasts even in remote areas, facilitating management for firefighters, farmers and forest managers alike.

The Forest Laboratory, funded by the Severo Ochoa programme, offers open access to its data and applications. Any user can consult, download and use the information for their own projects. In addition, the platform includes tools to follow the health status of Catalan forests, reinforcing surveillance against possible environmental threats.

CREAF, based in Bellaterra, has established itself as a benchmark in forest research and environmental management in Catalonia. Its commitment to open science and digitalisation has enabled both public administrations and citizens to have precise information on the state of forests and water resources. In recent years, its applications have been key to anticipating risks and planning strategies in response to climate change, placing Catalonia at the forefront of Mediterranean ecosystem monitoring.