In a recent paper, the authors report the analysis of ionospheric TEC data from GPS measurements around the time of the 6 April 2009 L'Aquila earthquake. According to them, an anomalous change in TEC difference from two GPS receivers in central Italy may be explained as related to the earthquake. We have conducted our own independent analysis using the same GPS data. We have shown that in TEC difference there is no evidence of actual seismogenic effects close to the time of L'Aquila earthquake.

Heatwave conditions prevailed at over wide regions of central and northern India during March–April–May 2016. A prevailing heatwave over India took more than 500 lives. Here we investigate the extreme events (heatwaves) using a high-resolution numerical weather prediction and its ensemble forecast in union with classical statistical scores to serve verification purposes.

Some interesting questions were raised during the review process of a recent paper on a method for obtaining a fallen-block volume-frequency law, e.g. related to the minimum number of observations needed for obtaining the law. This brief communication addresses this point. In detail, the errors due to a reduced number of recorded fallen-block events and to the consistency of the measured blocks at the foot of the cliff are computed. This is useful for design purposes.

The study of the shallow coastal area of the Sele mouth in the Gulf of Salerno (southern Italy) identified the features of nearshore circulation, which often produced rip currents. The occurrence of a rip current cell circulation in restricted ranges of heights, periods and incident directions was related to the non-dimensional fall velocity parameter, which proved to be an efficient index for rip current formation.

Geomorphic impact of the 2015 flood of the Kinu River, which created a new crevasse splay on its floodplain, was quantified by volumetric calculations using three topographic data obtained by aerial laser scanning (ALS) and UAV photogrammetry. Topographic changes on the order of 0.1 m were detected, and the erosive character of the crevasse splay was revealed. The results suggest that a combination of ALS and UAV is useful for quantification of sudden topographic changes through disasters.

Current methods to identify landslides after an earthquake are too slow to effectively inform emergency response operations. This study presents an empirical approach for modelling the spatial pattern and landslide density within hours to days of the earthquake. The approach uses small initial samples of landslides to identify locations where as yet unidentified landslides may have occurred. The model requires just 200 initial landslides, provided they have sufficiently wide spatial coverage.

Flash flooding is the leading cause of weather-related deaths. Therefore, a comprehensive assessment of the social risk component is necessary. Integrated social vulnerability can incorporate spatial distribution and contribution and the combined effect of exposure, sensitivity and resilience, and it can be expressed as the integrated social vulnerability index (ISVI). ISVI makes it possible to design tailor-made strategies for flood risk management, thereby increasing the efficiency of plans.

We used state-of-the-art numerical models and statistical approaches to investigate coastal flooding due to hurricanes and sea level rise for Martinique. The nonlinear interactions of surges with sea level rise are found to reach several tens of centimeters in low-lying areas where the inundation extent is strongly enhanced compared to present conditions. The results presented is this paper are of primary interest to coastal planners and decision makers in Martinique and the Lesser Antilles.

The French Institute of Radioactive Protection and Nuclear Safety, with the support of the Ministry of Environment, compiled a database (BDFA) in order to define and characterize known potentially active faults of metropolitan France. The general structure of BDFA is presented, containing to date a total of 136 faults (581 fault segments). BDFA represents a first step toward the implementation of seismic source models for both deterministic and probabilistic seismic hazard calculations.

We perform a fault-based PSHA exercise in the Upper Rhine Graben to quantify the relative influence of fault parameters on the hazard at the Fessenheim nuclear power plant site. Sensitivity tests show that the uncertainty on the slip rate of the Rhine River fault is the dominant factor controlling the variability of the seismic hazard level, greater than the epistemic uncertainty due to ground motion prediction equations (GMPEs).

Deep-seated landslides are an important and widespread natural hazard within alpine regions and can have a massive impact on infrastructure. Pore water pressure plays an important role in determining the stability of hydro-triggered deep-seated landslides. Here we demonstrate a modified tank model for deep-seated landslides that includes snow and infiltration effects and can effectively predict changes in pore water pressure in alpine environments.

Rainfall is more intense at high temperatures than in cooler weather, as can be seen in summer thunder storms. The relationship between temperature and rainfall intensity seems to invert at very high temperatures, however. There are some possible meteorological explanations, but we propose that part of the reason might be the low number of observations, due to which the actually possible values are underestimated. We propose a better way to estimate high quantiles from small datasets.

This study describes the development of a model, called MobRISK, for assessing motorists' exposure to road flooding. MobRISK combines sociodemographic, travel-activity and hydrometeorological data in order to simulate the number and the profile of exposed persons to road flooding. The first application of MobRISK in a case study in southern France enabled the identification of the most dangerous road sections based on a spatiotemporal exposure index and the profile of most exposed people.

We studied the highest wave events in the Baltic Sea using wave measurements available since 1996. Going beyond classifying them based solely on the maximum wave height, we found that they can be divided into two groups based on, for example, the length of the storm. Two of the severest storms show different behaviour, with the most recent (in 2017) being the longest on record. We hope this more in-depth description of the storms will aid in the issuing of warnings for extreme wave conditions.

To quantify the relevance of surface water floods in Switzerland, we introduce and analyze an exhaustive set of insurance flood damage claims. First, we present a method to classify such claims and then we analyze the classified data with respect to space and time. The results reveal that just as fluvial floods are responsible for vast damage in Switzerland, so too are surface water floods. Accordingly, surface water floods should receive similar attention like fluvial floods.

Flood damage models are an important component of cost–benefit analyses for flood protection measures. Currently flood damage models predict the flood damage often only based on water depth. Recently, some progress has been made in also including other variables for this prediction. Data-intensive approaches (machine learning) have been applied to do this. In practice the required data for this are rare. We apply these new approaches on a new type of dataset (combination of different sources).