idw – Informationsdienst Wissenschaft

Nachrichten, Termine, Experten

Grafik: idw-Logo
Grafik: idw-Logo

idw - Informationsdienst
Wissenschaft

Science Video Project
idw-Abo

idw-News App:

AppStore

Google Play Store



Instance:
Share on: 
11/13/2020 11:41

Coastal Floods: Researchers at the University of Graz assess compound flood hazard for coastal areas worldwide

Mag. Konstantinos Tzivanopoulos Presse + Kommunikation
Karl-Franzens-Universität Graz

    Compound flooding arises from storms causing concurrent extreme meteorological tides (that is the superposition of storm surge and waves) and precipitation. This flooding can severely affect densely populated low-lying coastal areas. Here, combining output from climate and ocean models, we analyse the concurrence probability of the meteorological conditions driving compound flooding. We show that, under a high emissions scenario, the concurrence probability would increase globally by more than 25% by 2100 compared to present. In latitudes above 40o north, compound flooding could become more than 2.5 times as frequent, in contrast to parts of the subtropics where it would weaken.

    Sea level is rising. As a consequence, flood risk will increase along many coasts of the world. But in many river deltas a further natural hazard exists: if a storm surge co-occurs with heavy rainfall, the surge can block the runoff into the sea and thereby cause flooding in the delta.

    Currently, risk assessments consider storm surges and heavy precipitation independently. But as both phenomena can be caused by the same phenomenon, such events happen considerably more often that expected when assuming them being independent. In 2019, an international team of researchers lead by the University of Graz has assessed the influence of climate change on such compound flooding for European coasts. This study was now extended to coastlines worldwide and is the first to examine the global hazard of concurrent storm surges and heavy precipitation as well as to assess the influence of climate change on this hazard. The study has been published in the journal Communications Earth & Environment.

    Researchers of the Department of Meteorology at Reading University (UK) and the Wegener Center for Climate and Global Chang at the University of Graz (Austria) have analysed climate model simulations of storms and precipitation together with simulations of storm surges, conducted by researchers from the European Commission's Joint Research Center in Ispra, Italy.
    They found that compound flooding happens mainly in the westerlies and regions affected by Tropical storms such as hurricanes and typhoons. “This hazard will increase in the next decades in the mid- and high latitudes caused by more intense rainfall along with climate change. Particularly affected regions are, in the northern hemisphere, the US, Canada, Northern Europe, China, Korea and Japan; and, in the southern hemisphere, the south coast of South America and New Zealand.“, says Maraun.
    The results of these analyses can serve as a basis for further detailed studies, that consider further local characteristics such as the exact coastline, harbours and coastal protection measures.


    Contact for scientific information:

    Assoz. Prof. Dr. Douglas Maraun
    Wegener Center for Climate and Global Change at the University of Graz
    Tel.: +43 (0)664/88 32 68 27
    E-Mail: douglas.maraun@uni-graz.at


    Original publication:

    E. Bevacqua, M.I. Vousdoukas, G. Zappa, K. Hodges, T.G. Shepherd, D. Maraun, L. Mentaschi, & L. Feyen. More meteorological events that drive compound coastal flooding are projected under climate change. Communications Earth & Environment, 2020. DOI 10.1038/s43247-020-00044-z.


    Images

    Criteria of this press release:
    Business and commerce, Journalists, Scientists and scholars
    Environment / ecology, Geosciences, Oceanology / climate
    transregional, national
    Research results, Scientific Publications
    English


     

    Help

    Search / advanced search of the idw archives
    Combination of search terms

    You can combine search terms with and, or and/or not, e.g. Philo not logy.

    Brackets

    You can use brackets to separate combinations from each other, e.g. (Philo not logy) or (Psycho and logy).

    Phrases

    Coherent groups of words will be located as complete phrases if you put them into quotation marks, e.g. “Federal Republic of Germany”.

    Selection criteria

    You can also use the advanced search without entering search terms. It will then follow the criteria you have selected (e.g. country or subject area).

    If you have not selected any criteria in a given category, the entire category will be searched (e.g. all subject areas or all countries).