气候因子对全球洪水的影响及其驱动机制

Impacts of Climatic Indices on Global Flooding and Their Driving Mechanisms

气候变化对洪水时空演变具有重要影响。然而,由于缺乏全球水文观测数据,现有研究集中于区域尺度,难以形成洪水变化与气候因子关系的全球性认识。本文通过整编全球最新实测水文数据集,系统评估全球洪水变化与气候因子的关系及其影响机理。结果表明,气候因子对全球洪水变化具有显著的影响。其中,南方涛动(SOI)对北美、南美以及澳大利亚的洪水影响最为显著,印度洋海温偶极子(IOD)对欧洲和南美的洪水影响最为显著,欧洲、北美洪水多受大西洋多年代际振荡(AMO)影响,而太平洋年代际振荡(PDO)主要影响南美和欧洲的洪水。气候因子主要通过改变海平面气压和大气环流,对全球洪水产生影响。本文对理解全球洪水变化及其形成机理有重要意义。

Flooding is one of the extreme hydrologic events with the most severe socio-economic losses worldwide.The newly-issued observed streamflow datasets were used to examine the response of flood change to climate indices and their underlying mechanisms.Global assessment indicates that the flood change is significantly correlated with climate indices.Southern Oscillation Index(SOI)had a significant impact on North and South America as well as Australia,while the Indian Ocean Dipole(IOD)has a significant impact on flooding in Europe and South America.Europe and North America are affected by the Atlantic Multi-decadal Oscillation(AMO).The Pacific Decadal Oscillations(PDO)mainly affects South America and Europe.Moreover,atmospheric circulation,sea surface temperature,and sea level pressure related to the dominant climate index can well explain the relationship between climate index and flood changes.This study clarifies the relationship and its driving mechanism between climate indices and flood change,which could have great significance to flood risk management.