Post-Flood Resilience Assessment of July 2021 Flood in Western Germany and Henan, China

Abstract

In July 2021, devastating floods occurred in western Germany and Henan, China, resulting in extreme loss of life and property damage. Despite the differences in context, climate change contributed to these events. Flood resilience generally means the system’s ability to recover from floods. A post-flood resilience assessment seeks to determine the impact of the flood on the area, the duration it took to recover, the effectiveness of the measures taken to reduce the risk of flooding, and ways to enhance flood resilience. The post-flood review capacity method was used to assess the event and calculate the flood resilience index. Western Germany experienced a 500-year return period flood in connection with the low-pressure system, Bernd, while Zhengzhou in Henan experienced a 1000-year return period flood with the influence of Typhoon In-Fa and the Western Pacific subtropical high. More than 107,000 people were affected in Germany, with 205 deaths that account for USD 40 billion in economic losses, whereas in Henan, 14.786 million people were affected, and 398 people died, which accounts for USD 18.9 billion in losses. Germany was more impacted and took longer to restore essential services than Henan, China. The flood resilience index shows that the resilience level of both countries is low. The severe rainstorms in Zhengzhou and the Ahr River Valley exposed weaknesses in urban disaster management, particularly in urban areas, such as subway flooding and risk communication with the public. The events highlighted the need to better understand risks and their consequences, early warning systems, preparedness, and emergency response.