Llasat-Botija et al. (2025) The Application of Citizen Science to Evaluate the Emergency and the Response of the Population in the October 2019 Flash Flood Event in the Francolí River (NE Spain)

Identification

• Journal: Water
• Year: 2025
• Date: 2025-02-20
• Authors: Montserrat Llasat-Botija, Laura Esbrí, Tomeu Rigo, María Carmen Llasat
• DOI: 10.3390/w17050610

Research Groups

• Applied Physics Department, Universitat de Barcelona, Barcelona, Spain
• Institut de Recerca de l’Aigua (IdrA), Barcelona, Spain
• Servei Meteorològic de Catalunya, Barcelona, Spain

Short Summary

This paper applies citizen science to evaluate the emergency and population response during the October 2019 flash flood in the Francolí River (NE Spain), demonstrating its utility in reconstructing events, assessing impacts, and identifying key areas for improving flood prevention, response, and recovery processes.

Objective

• To analyze a flood emergency, the population's response, and how it can be improved through detailed analysis of actions taken during the emergency.
• To present a methodology based on citizen science as a tool to (1) reconstruct and analyze citizen response and perception, (2) interpret impacts and identify effective/ineffective measures, and (3) validate new methodologies for meteorological monitoring.

Study Configuration

• Spatial Scale: Upper Francolí River watershed, Catalonia (NE Spain), primarily Conca de Barberà county (approximately 650.2 km²).
• Temporal Scale: The flash flood event occurred from 22 to 23 October 2019. The FLOODUP-Francolí citizen science campaign was conducted from March to June 2020, with results presented in October 2020.

Methodology and Data

• Models used:
  • Identification and monitoring algorithm developed by Esbrí et al. (2021) for characterizing convective nuclei.
  • Hydrological and hydraulic simulation by Martín Vide et al. (2020) for flow reconstruction.
• Data sources:
  • Citizen Science: FLOODUP-Francolí campaign (online questionnaires, FLOODUP mobile application, social media hashtag #Aqueloo_Francoli, email submissions of data, photographs, testimonies, and experiences).
  • Meteorological: Meteorological Service of Catalonia (SMC) (rainfall data, XRAD C-band Doppler radar network products including 1 km CAPPI, VIL, TOP12, TOP45), State Meteorological Agency (AEMET) (rainfall data), Meteoprades network (amateur weather stations).
  • Hydrological: Catalan Water Agency (ACA) (gauging station data in Montblanc), reconstructed flow data.
  • Emergency Management: Direcció General de Prevenció, Extinció d’Incendis i Salvaments (firefighter actions), Centre d’Atenció i Gestió de Trucades d’Urgència 112 Catalunya (CAT112) (emergency calls), Civil Protection (INUNCAT plan activation, warnings, press releases, social media).
  • Impacts & Economic: Press, government press releases, X (formerly Twitter), INUNGAMA database (historical floods in Catalonia), Consorcio de Compensación de Seguros (CCS) (economic compensation data).
  • Remote Sensing: Copernicus EMS Rapid Mapping service.

Main Results

• Hydrometeorological Event: The flash flood on 22–23 October 2019 was a compound event. Maximum accumulated precipitation reached 292.6 mm in Prades and 165.5 mm in L’Espluga de Francolí, with intensities exceeding 40 mm in 30 minutes in the Prades Mountains. River flow in Montblanc rapidly increased from 2 m³/s to 186 m³/s in 5 minutes, peaking over 600 m³/s, carrying significant debris.
• Impacts: The event caused 5 fatalities in the study area and EUR 7.4 million in flood damage compensation from CCS. It led to the destruction of a winery, a restaurant, bridges, and severe damage to communication networks (railway tracks cut for months), 36 hectares of crops, and 87 hectares of forests. Indirect impacts included power, water, and telephone outages, business disruption, and significant emotional distress.
• Emergency Management and Population Response: Initial meteorological warnings were issued by SMC on 21 October, leading to INUNCAT plan activation from pre-alert to emergency. However, there was confusion due to divergent warnings from SMC and Civil Protection, and a lack of public understanding on how to interpret and act on them. The Francolí basin recorded 94 calls to 112 (4 calls per 1000 inhabitants) and 29 firefighter interventions. The population perceived delays in institutional response, leading to rapid grassroots organization (e.g., "Riuada Solidària" platform raising over EUR 150,000).
• Citizen Science Campaign: The FLOODUP-Francolí campaign, despite challenges like the COVID-19 pandemic and other concurrent events, engaged 30 active participants. Most participants (60%) described the event as exceptional, like a "tsunami or explosion." The campaign revealed gaps in communication clarity, lack of agreed-upon community protocols, and the critical role of community self-organization in the immediate aftermath.

Contributions

• Provides a unique, bottom-up perspective on flood emergency analysis by integrating citizen science data with official meteorological and hydrological information, offering a comprehensive understanding of population perception, behavior, and impacts.
• Demonstrates the value of citizen science in capturing indirect and intangible impacts (e.g., emotional health, long-term mobility disruptions, community solidarity) that are often missed by traditional assessment methods.
• Identifies specific weaknesses in existing early warning systems and emergency management, such as communication inconsistencies, timing of alerts, and lack of community-agreed self-protection protocols, offering actionable recommendations for improvement.
• Highlights the importance of local historical memory in shaping risk perception and preparedness, and the need for its preservation and integration into future flood risk management strategies.

Funding

• Project "Analysis for the improvement of early warning systems and the creation of a Flood Observatory and other participatory tools" (AGORA, ACA210/18/00009) by the Catalan Water Agency.
• Spanish project C3RiskMed (PID2020-113638RB-C22 funded by MICIU/AEI/10.13039/501100011033, Ministry of Science, Innovation and Universities (Spain)).
• Flood2Now (Grant PLEC2022-009403 funded by MICIU/AEI/10.13039/501100011033 and by the “European UnionNextGenerationEU/PRTR”).
• AQUELOO project (FCT-18-13408, FECYT, MICIU).

Citation

@article{LlasatBotija2025Application,
  author = {Llasat-Botija, Montserrat and Esbrí, Laura and Rigo, Tomeu and Llasat, María Carmen},
  title = {The Application of Citizen Science to Evaluate the Emergency and the Response of the Population in the October 2019 Flash Flood Event in the Francolí River (NE Spain)},
  journal = {Water},
  year = {2025},
  doi = {10.3390/w17050610},
  url = {https://doi.org/10.3390/w17050610}
}