Search Results (4)

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. Full article

More than 130 lives were lost in the 2021 heavy precipitation and flood event in the Ahr Valley, Germany, where large parts of the valley were destroyed. Afterwards, public funding of about 15 billion Euros has been made available for reconstruction. However, with people and settlements being in highly exposed zones, the core question that is not sufficiently addressed is whether affected people want to rebuild in the same place, or rather opt to move out. The paper explores this question and assesses motivations and reasons for moving or staying in the Ahr Valley. For this purpose, a household survey was conducted focusing on 516 flood-affected households. The collected data was analyzed using descriptive and inferential statistics. The results revealed that the ownership of the house or flat significantly influenced the decision of whether to stay or to leave. In addition, an attachment to the place and the belief that such extreme events occur very rarely influenced the decision to stay and rebuild. Age, gender and household income barely influenced the decision to stay or to move to a new place. Interestingly, results demonstrated that many respondents view settlement retreat and the relocation of critical infrastructures as important options to reduce risk, however, many still rebuild in the same place. These insights enable local policy and practice to better address the needs of the population in terms of whether to stay or move after such an extreme disaster. Full article

In contrast to river floods, the enormous erosion potential in catchments contributes significantly to the extent of damage to infrastructure in valleys. This paper investigates the impact of the heavy precipitation event of 14–15 July 2021 on the railroad in the Ahr valley in Rhineland-Palatinate, Germany. In a first step, a detailed overview of the climatological and hydrological drivers using spatially high-resolved precipitation distribution and peak discharge modeling is provided, and the event is placed in a broader context by comparing it to past flash flood events from 1910 and 2016. In a second step, a detailed mapping of damages along the railroad line is performed using aerial photographs. The mapping revealed that bridges are the weakest point during a flood event and that they contribute to an increase and modification of the flood wave through backwater effects. Since flood events are expected to increase in the future, there is an urgent need to increase the resilience of transportation to this hazard and to answer the question of what magnitudes and return periods of events should be used in future sizing of rail infrastructure. Full article

On 22 July 2019, mesoscale convective systems (MCSs) with an abrupt heavy rainfall event (AHRE) hit Shuicheng County of Guizhou Province in Southwest China causing landslide and debris flow secondary disasters. The AHRE over the complex terrain of Shuicheng County had differences in location and intensity during two stages of the event. The two stages could be divided into different rainfall types (topographic rainfall and synoptic-weather-related rainfall) according to the spatiotemporal distribution and organization of MCSs based on surface and midlevel environmental field conditions. During the topographic rainfall stage, smaller meso-γ-scale (2–20 km) convective cells with lower echo-top heights (6–10 km) occurred along the windward slope of the primary mountain peak. During the synoptic-weather-related rainfall stage, a meso-β-scale (20–200 km) convective echo band with higher echo-top heights (10–14 km) occurred in the valley of the region. An adverse wind area (AWA) with distinct convergence of radar radial velocity existed over Shuicheng County. A formation mechanism analysis of the AHRE showed that topographic rainfall occurred in the warm and moist area, while synoptic-weather-related rainfall occurred due to local convergence and the intrusion of a cold tongue. Compared to the early stage, the cold tongue from the higher terrain superimposed over the warm sector at the base of major mountain ranges appeared to strengthen the rainfall. Full article