With growing support for nature-based solutions to reduce flooding by local communities, government authorities and international organisations, it is still important to improve how we assess risk reduction. We demonstrate an efficient, simplified 1D network model that allows us to explore the whole-system response of numerous leaky barriers placed in different stream networks, whilst considering utilisation, synchronisation effects and cascade failure, and we provide advice on their siting.

In North Africa, the vulnerability to floods is high, and there is a need to improve the flood-forecasting systems. Remote-sensing and reanalysis data can palliate the lack of in situ measurements, in particular for soil moisture, which is a crucial parameter to consider when modeling floods. In this study we provide an evaluation of recent globally available soil moisture products for flood modeling in Morocco.

We explore the role of waves, storm surges and sea level rise for the Caribbean region with a focus on the eastern Caribbean islands. We simulate past extreme events, suggesting a storm surge might reach 1.5 m and coastal wave heights up to 12 m offshore and up to 5 m near the coast of St Vincent. We provide sea level projections of up to 2.2 m by 2100. Our work provides quantitative evidence for policy-makers, scientists and local communities to actively protect against climate change.

Flood risk management is especially complicated in coastal cities. The complexity of multiple flood hazards in a rapidly changing urban environment leads to a situation with many different potential measures and future scenarios. This research demonstrates a new model capable of quickly simulating flood impact and comparing many different strategies. This is applied to the city of Beira, where it was able to provide new insights into the local flood risk and potential strategies.

In operational flood risk management, a single best model is used to assess the impact of flooding, which might misrepresent uncertainties in the modelling process. We have used quantified uncertainties in flood forecasting to generate flood hazard maps that were combined based on different exceedance probability scenarios with the purpose to differentiate impacts of flooding and to account for uncertainties in flood hazard maps that can be used by decision makers.

Rogue waves pose a threat to marine operations and structures. Typically, a wave is called a rogue wave when its height exceeds twice that of the surrounding waves. There is still discussion on the extent to which such waves are unusual. A new data set of about 329 million waves from the southern North Sea was analyzed. While data from wave buoys mostly corresponded to expectations from known distributions, radar measurements showed some deviations pointing towards higher rogue wave frequencies.

Full dependence is assumed between drivers in flood protection assessments of coastal water control structures in south Florida. A 2-D analysis of rainfall and coastal water level showed that the magnitude of the conservative assumption in the original design is highly sensitive to the regional sea level rise projection considered. The vine copula and HT04 model outperformed five higher-dimensional copulas in capturing the dependence between rainfall, coastal water level, and groundwater level.

We develop a framework that links the volume of hydraulic fracturing fluid injected during shale gas exploration with the likelihood that resulting seismicity causes a nuisance to nearby populations. We apply the framework to a shale gas site in England and find that the potential of a given injected volume to produce nuisance ground motions is especially sensitive to assumptions about the amount of seismic energy released during operations. The work can inform policy on shale gas exploration.

The Weather Research Forecasting with Chemistry (WRF-Chem) model was modified to include volcanic ash aggregation. The modified WRF-Chem model was run with and without aggregation, and changes in the model output were measured. Changes in the lifetime of volcanic ash a function of the chosen fractal dimension were quantified. A case study using the 2010 eruptions of Eyjafjallajökull revealed that the aggregation modifications result in tephra fallout and ash concentrations near observed values.

The effect of El Niño on flood damage was investigated. The methodology was based on the calculation of increasing rainfall amount during El Niño events compared to normal conditions. With the southern oscillation index equal to −1.0 as the threshold of El Niño, the annual percentage of increased rainfall is 12.2 %. The annual change factor may not necessarily be transferred to extreme values. Nonetheless, the change factor was applied for generating simulated storms of different return periods.

Heavy precipitation causes serious losses and several casualties in the western Mediterranean every year. To predict this phenomenon better, we aim at understanding how the models represent the interaction between atmospheric moisture and precipitation by nudging a 10 min, state-of-the-art GPS data set. We found, for the selected case in autumn 2012, that the improvement in the modelling of precipitation stems from relevant variations of atmospheric instability and humidity above 1.5 km.

This study presents a method for the calculation of storm surge inundation simulation under different typhoon intensity scenarios. The parameters including typhoon track, radius of maximum wind speed, astronomical tide, and upstream runoff under different typhoon intensity scenarios were set. The inundation extents and depths corresponding to the storm surges under different typhoon intensity scenarios were simulated in combination with the numerical model.

Can numerical models simulate intense rainfall events and consequent streamflow in a mountainous area with small watersheds well? We applied state-of-the-art one-way-coupled atmospheric–hydrologic models and we found that, despite rainfall events simulated with low errors, large discrepancies between the observed and simulated streamflow were observed. Shifts in time and space of the modelled rainfall peak are the main reason. Still, the models can be applied for climate change impact studies.