Citizen-generated data, a climate adaptation complement: A case study in Brazil

Abstract. Flooding is the most prevalent type of disaster globally with stronger impacts in low-developed areas, where the collection of up-to-date, high-quality, and representative data for flood risk management remains a challenge. Citizen science and participatory mapping methods have the potential to contribute to data acquisition to better inform flood scenario description and grassroots civic engagement and advocacy, overcoming the shortcomings of the lack of data. This paper aims to understand how citizen science can contribute to climate adaptation in Brazil. Factors affecting adaptation to extreme flooding events, i.e. I) official monitoring (presence of weather stations and historical numbers of flooding); II) proportion of municipalities’ urban areas mapped as in risk of flooding; III) existence of educational strategies in disaster risk prevention; and IV) citizen engagement with local data production are analysed to check if interactions between them may indicate where participatory adaptation could be more inclusive. This is done through an exploratory analysis that combines numerical analysis with geoprocessing techniques using official and citizen-generated data from the Waterproofing Data project. Despite the existing data gaps, results show that adaptation resources tend to be more abundant in bigger cities and municipalities that have historically been affected by floods. The study concludes that citizen-generated data can provide valuable insights into adaptation and resilience while complementing official data.