Devastating floods in Spain witnessed by satellites

Published on 6 November 2024

Torrential rainfall causing deadly flash floods has hit southern and eastern Spain in regions including the Costa del Sol, where the city of Malaga is located, and Valencia in the east. As these areas struggle to cope with the aftermath, satellite technology has played a crucial role in assessing the damages of the affected areas.

The storms concentrated over the Magro, Turia and the Poyo river basins, releasing torrents of muddy water that turned village streets into rivers, destroyed homes and swept away bridges and vehicles. Over 200 people have lost their lives with thousands displaced and many still missing. Valencia’s coastal region was particularly hard-hit, receiving a year’s worth of rain in just eight hours, according to Spain’s national weather agency, Aemet.

Aemet reported that the extreme rainfall resulted from a high-altitude, low-pressure weather system isolated from the jet stream. Known locally as DANA, these storm systems form when cold fronts encounter warm, humid air masses, such as over the Mediterranean Sea. The storms can remain stationary before dissipating, increasing the potential for severe flooding.

Earth observation imagery and data are an important resource for emergency services, providing crucial information for near real-time response, post-event analysis and damage assessment. US Landsat-8 satellite images captured on 30 October were the first to illustrate the scale of the disaster, showing the drastic transformation of the landscape.

The Copernicus Sentinel-2 images below show the scale of the Valencia flooding disaster and the drastic transformation of the landscape.

Flood imagery captured by Copernicus Sentinel-2

Sentinel-1 radar images from 19 and 31 October illustrate the severe flooding of the Albufera National Park due to the discharge of the Magro, Turia and Poyo rivers. This park is bordered by the Mediterranean Sea to the east and encroaches on densely populated neighbourhoods to the west.

The Copernicus Emergency Rapid Mapping Service (EMS) was activated by the Directorate-General for Civil Protection and Emergencies (Dirección General de Protección Civil y Emergencias) on 29 October to create maps showing the extent and severity of the flooding in affected areas.

Several maps have been produced and published thus far, the first was published on 31 October, based on the GeoEye acquisition from that morning.

Further analysis, along with a WorldView image acquired on the same day, reveals that more than 4100 hectares and 3906 buildings were impacted, while more than 60,000 people, around 15 km of railways, and 531 km of roads were potentially impacted in the area of Horta Sud.

The Copernicus Emergency Management Service monitors the floods in Valencia, Spain

An analysis of Sentinel-1 and Sentinel-2 imagery acquired on 31 October over Valencia province produced a map on 2 November showing around 15,633 hectares of flooded area and approximately 190,000 people potentially affected.

Spain’s Civil Protection Agency also activated the International Charter ‘Space and Major Disasters’, which combines Earth observation assets from 17 space agencies and seven commercial data distributors from around the globe, to provide additional observations and analysis of the disaster zones.

The Charter provides this data on a best-effort, no-cost basis to aid in the response phase of major disasters. The Charter was activated on 1 November and it was agreed that the Copernicus EMS and the Charter would collaborate on this activation through the established data sharing agreements.

In addition to CEMS, several organisations have agreed to support the Charter activation through the provision of value-added products.

These organisations include LIST in Luxembourg, SERTIT in France, and MBRSC in the United Arab Emirates. These products, expected to be published on 6 November, will compliment those generated by the EMS by providing a more detailed analysis of the situation.

Flooded areas around Valencia captured by Sentinel-1

“Space-based observation plays an invaluable role during natural disasters like the recent floods in Spain,” said Simonetta Cheli, Director of Earth Observation Programmes at ESA.

“Our mission is to rapidly coordinate with partners through the International Charter and the Copernicus Emergency Mapping Service to deliver critical, real-time Earth observation data to aid emergency teams on the ground. We are committed to supporting rescue and relief efforts, providing the data needed to assess the damage and ensure timely response in affected communities.”

Beyond mapping damaged areas, satellites can help monitor the environmental conditions in an area affected by a hydrometeorological hazard such as the emergency that hit Spain. Data from ESA’s SMOS mission on 29 October further illustrated the situation, showing saturated ground around Valencia and other regions on the day of the floods.

The SMOS satellite, designed to measure global soil moisture over land and salinity over oceans, uses an innovative radiometer in the L-band microwave range to produce 'brightness temperature' images, which help derive soil moisture maps—an essential resource in the aftermath of such disasters.

High-resolution optical images captured by Pléiades Neo, an ESA Third Party Mission, on 31 October, reveal the extensive damage from the Valencia floods in extreme detail.