The 2018 west-central European drought projected in a warmer climate: how much drier can it get? Natural Hazards and Earth System Sciences DOI 10.5194/nhess-23-1921-2023 19 June 2023 To examine the impact of global warming on west-central European droughts, we have constructed future analogues of recent summers. Extreme droughts like 2018 further intensify, and the local temperature rise is much larger than in most summers. Years that went hardly noticed in the present-day climate may emerge as very dry and hot in a warmer world. The changes can be directly linked to real-world events, which makes the results very tangible and hence useful for climate change communication. Read more
The extremely hot and dry 2018 summer in central and northern Europe from a multi-faceted weather and climate perspective Natural Hazards and Earth System Sciences DOI 10.5194/nhess-23-1699-2023 31 May 2023 The objective of this study was to perform a comprehensive, multi-faceted analysis of the 2018 extreme summer in terms of heat and drought in central and northern Europe, with a particular focus on Germany. A combination of favourable large-scale conditions and locally dry soils were related with the intensity and persistence of the events. We also showed that such extremes have become more likely due to anthropogenic climate change and might occur almost every year under +2 °C of global warming. Read more
Evaluation of liquefaction triggering potential in Italy: a seismic-hazard-based approach Natural Hazards and Earth System Sciences DOI 10.5194/nhess-23-1685-2023 24 May 2023 In the present study, we analyse ground-motion hazard maps and hazard disaggregation in order to define areas in Italy where liquefaction triggering due to seismic activity can not be excluded. The final result is a screening map for all of Italy that classifies sites in terms of liquefaction triggering potential according to their seismic hazard level. The map and the associated data are freely accessible at the following web address: www.distav.unige.it/rsni/milq.php. Read more
Rescuing historical weather observations improves quantification of severe windstorm risks Natural Hazards and Earth System Sciences DOI 10.5194/nhess-23-1465-2023 15 May 2023 We examine a severe windstorm that occurred in February 1903 and caused significant damage in the UK and Ireland. Using newly digitized weather observations from the time of the storm, combined with a modern weather forecast model, allows us to determine why this storm caused so much damage. We demonstrate that the event is one of the most severe windstorms to affect this region since detailed records began. The approach establishes a new tool to improve assessments of risk from extreme weather. Read more
Brief communication: The northwest Himalaya towns slipping towards potential disaster Natural Hazards and Earth System Sciences DOI 10.5194/nhess-23-1425-2023 8 May 2023 The NW Himalaya has been one of the most affected terrains of the Himalaya, subject to disastrous landslides. This article focuses on two towns (Joshimath and Bhatwari) of the NW Himalaya, which have been witnessing subsidence for decades. We used a slope stability simulation to determine the response of the hill slopes accommodating these towns under various loading conditions. We found that the maximum displacement in these hill slopes might reach up to 20–25 m. Read more
A multi-disciplinary analysis of the exceptional flood event of July 2021 in central Europe – Part 2: Historical context and relation to climate change Natural Hazards and Earth System Sciences DOI 10.5194/nhess-23-1287-2023 19 April 2023 Heavy precipitation in July 2021 led to widespread floods in western Germany and neighbouring countries. The event was among the five heaviest precipitation events of the past 70 years in Germany, and the river discharges exceeded by far the statistical 100-year return values. Simulations of the event under future climate conditions revealed a strong and non-linear effect on flood peaks: for +2K global warming, an 18% increase in rainfall led to a 39% increase of the flood peak in the Ahr river. Read more
Brief communication: On the extremeness of the July 2021 precipitation event in western Germany Natural Hazards and Earth System Sciences DOI 10.5194/nhess-23-1227-2023 17 April 2023 Estimating the severity of a rainfall event based on the damage caused is easy but highly depends on the affected region. A less biased measure for the extremeness of an event is its rarity combined with its spatial extent. In this brief communication, we investigate the sensitivity of such measures to the underlying dataset and highlight the importance of considering multiple spatial and temporal scales using the devastating rainfall event in July 2021 in central Europe as an example. Read more
A climate-conditioned catastrophe risk model for UK flooding Natural Hazards and Earth System Sciences DOI 10.5194/nhess-23-891-2023 5 April 2023 We present and validate a model that simulates current and future flood risk for the UK at high resolution (~ 20-25 m). We show that UK flood losses were ~ 6 % greater in the climate of 2020 compared to recent historical values. The UK can keep any future increase to ~ 8 % if all countries implement their COP26 pledges and net-zero ambitions in full. However, if only the COP26 pledges are fulfilled, then UK flood losses increase by ~ 23 %, and potentially by ~ 37 % in a worst-case scenario. Read more
Performance of the flood warning system in Germany in July 2021 – insights from affected residents Natural Hazards and Earth System Sciences DOI 10.5194/nhess-23-973-2023 3 April 2023 In July 2021 intense rainfall caused devastating floods in western Europe with 184 fatalities in the German federal states of North Rhine-Westphalia (NW) and Rhineland-Palatinate (RP), calling their warning system into question. An online survey revealed that 35 % of respondents from NW and 29 % from RP did not receive any warning. Many of those who were warned did not expect severe flooding, nor did they know how to react. The study provides entry points for improving Germany’s warning system. Read more
A multi-disciplinary analysis of the exceptional flood event of July 2021 in central Europe – Part 1: Event description and analysis Natural Hazards and Earth System Sciences DOI 10.5194/nhess-23-525-2023 20 March 2023 The flood event in July 2021 was one of the most severe disasters in Europe in the last half century. The objective of this two-part study is a multi-disciplinary assessment that examines the complex process interactions in different compartments, from meteorology to hydrological conditions to hydro-morphological processes to impacts on assets and environment. In addition, we address the question of what measures are possible to generate added value to early response management. Read more
