對長度為2500年的一個時間段中歐洲阿爾卑斯山的強降水事件所做的一個全面重建表明，發(fā)生洪澇頻率高的時期往往與夏季氣溫低巧合,。發(fā)表在本期Scientific Reports上的這項研究有可能幫助改進對氣候變化條件下極端天氣的預測。
中歐的夏季平均氣溫預計在全球氣候變化下將會升高，同時夏季降水總量預計將會下降。洪澇發(fā)生頻率的潛在增加還可能會增加受影響地區(qū)（包括阿爾卑斯山地區(qū)）的人類定居點,、基礎設施和人類生命所面臨的風險。然而,，預測極端氣候（如強降水事件）的出現(xiàn)頻率難度卻要大一些,。
Lukas Glur及同事對來自瑞士阿爾卑斯山區(qū)十個湖泊的沉積物進行了研究，他們用放射性碳分析方法確定了其年代,。湖泊沉積物能準確反映過去的洪澇活動，因為它們能將各個事件記錄為截然不同的沉積層,。作者發(fā)現(xiàn),，洪澇在涼爽夏季發(fā)生頻率往往更高，同時他們也提出,，這種濕-冷天氣一起出現(xiàn)的情況可能是由大西洋和地中海風暴路徑的緯向偏移觸發(fā)的,。該研究提供的古氣候觀點可能會有助于更好了解全球氣候變化怎樣影響極端天氣事件和改進對未來更溫暖氣候條件下洪澇風險的評估。（生物谷Bioon.com）
生物谷推薦的英文摘要
Scientific Reports doi:10.1038/srep02770
Frequent floods in the European Alps coincide with cooler periods of the past 2500 years
Lukas Glur,，Stefanie B. Wirth,，Ulf Buntgen，Adrian Gilli,，Gerald H. Haug,，Christoph Schar，Jurg Beer& Flavio S. Anselmetti
Severe floods triggered by intense precipitation are among the most destructive natural hazards in Alpine environments,， frequently causing large financial and societal damage. Potential enhanced flood occurrence due to global climate change would thus increase threat to settlements,， infrastructure， and human lives in the affected regions. Yet,， projections of intense precipitation exhibit major uncertainties and robust reconstructions of Alpine floods are limited to the instrumental and historical period. Here we present a 2500-year long flood reconstruction for the European Alps,， based on dated sedimentary flood deposits from ten lakes in Switzerland. We show that periods with high flood frequency coincide with cool summer temperatures. This wet-cold synchronism suggests enhanced flood occurrence to be triggered by latitudinal shifts of Atlantic and Mediterranean storm tracks. This paleoclimatic perspective reveals natural analogues for varying climate conditions， and thus can contribute to a better understanding and improved projections of weather extremes under climate change.
