Special issue |
Hydroclimatic extremes and impacts at catchment to regional scales
Editor(s): C. Reason, R. Trigo, S. M. Vicente Serrano, and F. Domínguez-CastroMore information
We invite all hydroclimatic researchers to submit the results of their studies to a special issue of Natural Hazards and Earth System Sciences (NHESS) addressing the theme of hydroclimatic extremes and impacts at catchment to regional scales. Please find the instructions for authors on the NHESS web page. The individual papers will be peer-reviewed and published as soon as they are available in regular issues but will be labelled as part of the special issue and linked electronically. The main purpose of the special issue is to focus on hydroclimatic extremes (floods and droughts) at catchment and regional scales and their impacts on a broad range of hydrological and environmental systems, including mitigation approaches. Nevertheless, broad topics around hydroclimatic extremes (e.g. temporal variability and trends, atmospheric mechanisms, propagation throughout the hydrological cycle, hydrological modelling of extremes) and the impact of climate change on hydroclimatic extremes are also encouraged. The special issue was inspired by the Water-JPI IMDROFLOOD project but submissions from all researchers working on suitable topics are welcome, even if they are not participating in the project. In fact, all scientists working on this topic should feel able to contribute. Therefore, please forward this call for papers to your colleagues.
Quantifying the exposure of house property to extreme weather events is crucial to study their impact on economy. Here, we show that value of property exposed to Hurricane Florence in September 2018 was USD 52 billion vs. USD 10 billion that would have occurred at the beginning of the 19th century due to urban expansion that increased after 1950s and the increasing number of houses built near water, showing the importance of accounting for the distribution of new buildings in risk and exposure.
The main objective of this paper is to estimate changes in the probability of damaging flood events with global warming of 1.5, 2 and 3 °C above pre-industrial levels and taking into account different socioeconomic scenarios in two western Mediterranean regions. The results show a general increase in the probability of a damaging event, with larger increments when higher warming is considered. Moreover, this increase is higher when both climate and population change are included.
This work investigates the dependence between drought hazard and yield anomalies of rainfed cropping systems in the Iberian Peninsula using the copula theory. The applied methodology allows us to estimate the likelihood of wheat and barley loss under drought conditions, and a dependence among extreme values is suggested. From the decision-making point of view this study aims to contribute to the mitigation of drought-related crop failure.
A vulnerability assessment method is proposed to identify the most vulnerable regions over Portugal. Two methods were compared, namely a subjective categorical method and an automatic method, based on drought indicators, vegetation indices and soil variables. Both methods present similar results, and both identify Minho (Alentejo) as having low (extreme) vulnerability. The automatic method has advantages, as it is fully statistical and presents results without prior knowledge of the region.
An early-warning system (EWS) for flood prediction was developed in the upper reach of the Miño River and the city of Lugo (NW Spain). This EWS can provide accurate results in less than 1 h, for a forecast horizon of 3 d, and report an alert situation to decision makers in order to mitigate the consequences of floods. In addition, this EWS can be easily adapted for any area of the world since the required input data and software are freely available.
On 9 October 2018, an extreme convective storm (> 300 mm accumulated in 6 h) generated a flash flood (305 m3 s−1) in the Ses Planes torrent that devastated the town of Sant Llorenç (Mallorca, Spain). Water reached a depth of 3 m in the most affected areas, and there was greatly increased flow velocity at bridges crossing the town. The floodwaters were very powerful and modified the channel morphology: more than 5000 t of sediment was deposited in the 2 km reach upstream of the town.
We developed a novel approach in using Bayesian networks (BNs) for ensemble flood forecasting in a case study in Iran. This allows fast early warning without the need for hydrological modelling. We recommend to combine precipitation ensembles with hydrological initial conditions in the BN. The number of observed flood events is low by nature. Under the limited amount of data, BN outperformed artificial neural networks with good results. Future work will validate the concept further.
The mapping of convective storms in the area of the transboundary Prut River basin was developed using a 15-year radar dataset (2003–2017). The analysis is based on data sampled in successive 6 min scans of the atmosphere, to detect and track the convective storms. The results highlighted a yearly, monthly, and daily variation of convective activity but also spatial distribution patterns. The study of atmospheric convection is important in assessing the risks associated with extreme weather.
Drought events are of great importance in most Mediterranean climate regions, and the impacts caused on rainfed crops are particularly evident. In this study the impacts of drought on two representative rainfed crops in Spain (wheat and barley) are assessed by testing various worldwide drought indices and two datasets at different spatial resolution.
Sergio M. Vicente-Serrano, Cesar Azorin-Molina, Marina Peña-Gallardo, Miquel Tomas-Burguera, Fernando Domínguez-Castro, Natalia Martín-Hernández, Santiago Beguería, Ahmed El Kenawy, Iván Noguera, and Mónica García
Drought is a major driver of vegetation activity in Spain. Here we used a high-resolution remote-sensing dataset spanning the period from 1981 to 2015 to assess the sensitivity of 23 vegetation types to drought across Spain. Results demonstrate that vegetation activity is controlled largely by the interannual variability of drought. Nevertheless, there are some considerable spatio-temporal variations, which can be linked to differences in land cover and aridity conditions.
We mapped – for the first time – the probability of occurrence of drought over Spain, with the overriding aim of improving current drought assessment, management and mitigation measures, and strategies across the region. Spatially, our estimations suggest a higher probability of extreme drought events in southern and central areas of Spain compared to northern and eastern regions. Nevertheless, there are strong differences among drought indices and drought timescales.
Rainfall intensity–duration–frequency (IDF) curves are used as the basis for water resource infrastructure design. Given intensification of the hydrological cycle with global warming, quantitative information on the future extreme rainfall hazard is needed by practitioners. Projected changes in annual maximum rainfall in high-resolution regional climate model simulations result in IDF curves that shift upward and steepen, with greater intensification at short durations and long return periods.