Leveraging Citizen Science for Flood Hazard Management: Harnessing Local Knowledge and Experience
Authors: Fischer-Stabel Peter , Nau Sascha 
Published: March 2024

Floods pose significant challenges to communities worldwide, necessitating effective hazard management strategies. Citizen science here emerges as a pivotal tool in amassing critical knowledge and experiences from local communities, offering an invaluable resource to bolster flood hazard management initiatives. It is able to serve as a conduit for integrating diverse local perspectives and experiences. Harnessing the collective wisdom of community members, who intimately understand the dynamics of their surroundings, becomes instrumental in comprehending flood patterns, vulnerabilities, and impacts and is able to enrich the database for hydrological and hydraulic modelling in the flood context. Nowadays, the advent of citizen science apps represents a paradigm shift in engaging and mobilizing local communities to actively participate in flood hazard management.Within the framework of the BMBF R&amp;D &#8211; Project &#8220;Urban Flood Resilience &#8211; Smart Tools (FloReST)&#8221; one tool developed was a SmartApp engaging local communities in the collection of flash flood related data and experiences. After the definition of the user requirements in collaboration with the local stakeholders, a first prototype was developed, engaging the citizens in the reference municipalities of the FloReST-project to organize App-Journeys collecting data in the field. Beside a description of the problem to be choosen from a predefined list of flood related grievances (e.g. drain blockages, faulty rakes, building activities changing the draining system), the Geolocation of the position, additional textual information, up to three images and a time stamp is collected and send via the smartphone to a Gesoserver at the Backend. There &#8211; located ideally at the responsible organizational unit for flood related activities, e.g. the building or the environmental authority- the incoming messages are stored in a database and visualized on a risk-map with different graphical signatures depending on the category of the problem reported. After having received the report, a notice confirming the reception of the message is automatically send back to the client. The SmartApp now is able to facilitate the data collection on flood occurrences, affected areas, and vulnerabilities. Integration of such data with existing models enhances the accuracy and precision of flood risk assessments, enabling authorities to develop targeted mitigation and response plans.But, the idea behind this SmartApp is not only the collection of flood related local knowledge, moreover, this citizen science initiative intends to promote community engagement and empowerment, fostering a sense of responsibility among residents towards flood resilience.However, several challenges exist in the implementation of citizen science for flood hazard management: Quality assurance and data reliability remain concerns, necessitating robust protocols for data validation and verification. In addition, the responsible authorities we discussed with were not very happy with that type of citizen science tools for deficiency reporting, because this will force them to action often not possible in a short time because of a lack in resources.