Citizen science and natural disasters: experience report of community participation in mapping areas affected by extreme hydrological events in 2023 and 2024 in the Taquari Valley, RS, Brazil

ABSTRACT: This paper presents an experience gained from two initiatives conducted in the aftermath of extreme hydrological events that occurred in the Taquari-Antas River Basin, Rio Grande do Sul, Brazil, between 2023 and 2024. Through citizen science, students and local residents were mobilized to join efforts in mapping the extent of the events’ impacts. Citizen science has increasingly become a valuable tool for scientific data collection and analysis, especially in the context of natural disasters. Initiatives of this nature were implemented during the floods, flash floods, and landslides that struck the Taquari Valley in 2023 and 2024, engaging the population in the identification and mapping of affected areas. The research project’s main goal was the creation of a Citizen Map, developed through a georeferenced database fed by information submitted by volunteers who traveled through the region and identified locations impacted by floods, flash floods, and landslides. The methodology relied on mobile devices to send geolocations, photographs, and descriptions of affected areas, following a simple protocol accessible via WhatsApp with internet connectivity. This collaborative action, coordinated by academic institutions such as UFRGS and Univates, made it possible to map over 600 affected sites. Both the processes carried out and the final product—the map—proved significant in technical-academic and social dimensions. The integration of community-provided data with specialized software enabled the validation and refinement of hydrological and geotechnical modeling performed by the academic team. Furthermore, the Citizen Map gained substantial visibility. Socially, the initiative fostered community engagement and heightened awareness about environmental impacts and the need for more effective public policies to address extreme weather events, thereby strengthening societal resilience. This citizen science initiative demonstrated its efficiency as a data collection tool in emergency situations, offering intensive and extensive information that would be difficult for scientists to obtain alone. Thus, the project highlighted the strong potential of collaboration between scientists and citizens in seeking solutions to complex environmental challenges, reinforcing the importance of community participation in disaster and risk management. Such initiatives should be encouraged and enhanced in all societies to bolster community resilience in the face of climate change, contributing meaningfully to the achievement of the 2030 Agenda.