Design Flaws at the Interface of Flood Forecasting, Early Warning and Disaster Response in the Disaster in Western Germany in July 2021—An Interdisciplinary Analysis

Extreme heavy rainfall in Western Europe on 13–15 July 2021 caused severe flooding, notably in Germany's Rhineland-Palatinate and North Rhine-Westphalia. This study examines Flood Forecasting, Early Warning, and Disaster Response weaknesses during this event, focusing on the city of Stolberg. An interdisciplinary mixed-methods approach integrated meteorological, hydrological, and social science research. Data included river gages, precipitation measurements, warnings, and 300 documents, with 30 expert interviews. Weaknesses included imprecise meteorological forecasts due to dynamic weather, leading to general warnings without specific impact guidance. Limited flood forecasting hindered local preparation and response, exacerbated by an emergency response system unprepared for the event's scale. The top-down approach of Flood Forecasting and Early Warning conflicted with the bottom-up processes of Disaster Response, hampering effective crisis management. The study reveals critical weaknesses and calls for improved forecasting, integrated response plans, communication protocols, and crisis channels to enhance flood resilience. Future research should explore these issues in other extreme flood events and compare international Flood Forecasting, Early Warning, and Disaster Response systems.