Despite transdisciplinary approaches being increasingly explored to study droughts and their impacts, their depth and breadth are yet to be fully exploited. By integrating insights from different research fields, we present five key dimensions to deepen and broaden the knowledge co-creation process for drought impact studies. Emphasizing social dynamics and power imbalances, we support hydrologists in developing more integrated, power-sensitive, inclusive, situated, and reflexive studies.

Compound events, where multiple weather or climate hazards occur together, pose significant risks to both society and the environment. These events, like simultaneous wind and rain, can have more severe impacts than single hazards. Our review of compound event research from 2012–2022 reveals a rise in studies, especially on events that occur concurrently, hot and dry events, and compounding flooding. The review also highlights opportunities for research in the coming years.

This paper investigates the relationship between changes in weather forecasts and predictability, which has so far been considered weak. By studying how weather scenarios persist over successive forecasts, it appears that conclusions can be drawn about forecasts' reliability.

Strong thunderstorms have been studied mainly over flat terrain in the past. However, they are particularly frequent near European mountain ranges, so observations of such storms are needed. This article gives an overview of our existing knowledge on this topic and presents plans for a large European field campaign with the goals to fill the knowledge gaps, validate tools for thunderstorm warnings, and improve numerical weather prediction near mountains.

Our research presents a new method for determining warning levels for any hazard. Using risk matrices, our framework addresses issues found in other approaches. Illustrative examples demonstrate how the approach works. A powerful method for evaluating warning accuracy is given, allowing for a cycle of continuous improvement in warning services. This research is relevant to a broad audience, from those who develop forecast systems to practitioners who issue or communicate warnings.

Local thresholds for landslide forecasting, combining hydrologic predisposing factors and rainfall features, are developed from a physically based model of a slope. To extend their application to a wide area, uncertainty due to the spatial variability of geomorphological and hydrologic variables is introduced. The obtained hydrometeorological thresholds, integrating root-zone soil moisture and aquifer water level with rainfall depth, outperform thresholds based on rain intensity and duration.

We analysed debris flows in Sichuan, China, using satellite data and simulations to assess check dam efficacy. Our study found that while check dams can mitigate smaller flows, they may increase exposure to extreme events, with up to 40 % of structures in some areas affected. Urban development and reliance on check dams can create a false sense of security, increasing exposure during large debris flows and highlighting the need for risk management and infrastructure planning in hazard-prone areas.

This study proposes a response-bias-tolerant methodology for estimating the production capacity loss rate (PCLR), which addresses response bias in extreme flood scenarios and considers the distribution characteristics of PCLR under different damage states. The core value of this study is to provide a competing and promising input in economic modeling, such as input–output and computable general equilibrium models.

Cities near volcanoes expose populations to hazards. We ranked 1106 cities by population exposed to volcanoes within < 100 km, nearest distance, and number of nearby volcanoes. Bandung ranks highest, with ~8 M exposed within < 30 km of 12 volcanoes. Jakarta leads populations exposed within <100 km (~38 M). Central America has the highest proportion of city exposure, with San Salvador near 23 volcanoes. We provide a global city exposure perspective, identifying areas for localized mitigation.

Multiple hazards, occurring simultaneously or consecutively, can have more extreme impacts than single hazards. We examined the disaster records in the global emergency events database EM-DAT to better understand this phenomenon. We developed a method to identify such multi-hazards and analysed their reported impacts using statistics. Multi-hazards have accounted for a disproportionate number of the impacts, but there appear to be different archetypal patterns in which the impacts compound.

We used a fiber optic cable along a road in western Norway to study snow avalanches signals. Our study shows that avalanches create distinct signals in the 20–50 Hz frequency range, with larger ones having weak early warning signals. However, road traffic interference complicates automatic detection. This research highlights the potential of using existing infrastructure for avalanche monitoring. Further improvements are needed for automated detection.

Brandenburg is among the driest federal states in Germany. The low groundwater recharge (GWR) is fundamental to both water supply and the support of natural ecosystems. In this study, we show that the decline of observed discharge and groundwater tables since 1980 can be explained by climate change in combination with an increasing leaf area index. Still, simulated GWR rates remain highly uncertain due to the uncertainty in precipitation trends.

The study assesses the practical predictability of an extreme rainfall event on 8 to 12 December 2018 over central Vietnam using quantitative precipitation forecasts (QPFs) from a time-lagged cloud-resolving ensemble system. To do this, 29 time-lagged (8 d in the forecast range) high-resolution (2.5 km) members were run every 6 h from 3 to 10 December 2018. Results reveal that the cloud-resolving model predicted the rainfall fields in the short range (less than 3 d) for 10 December (the rainiest day).