Shifting magnitude and timing of streamflow extremes and the relationship with rainfall across the Hawaiian Islands
Shifting magnitude and timing of streamflow extremes and the relationship with rainfall across the Hawaiian Islands
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夏威夷群岛极端水流的变化幅度和时间以及与降雨的关系
DOI：
10.1016/j.jhydrol.2021.126424
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发表时间：
2021
影响因子：
6.4
通讯作者：
Clilverd, Hannah M.
中科院分区：
文献类型：
--
作者：
Huang, Yu-Fen;Tsang, Yinphan;Strauch, Ayron M.;Clilverd, Hannah M.
洪水对夏威夷的生命和财产构成重大威胁。随着气候变暖继续改变热带地区的降水模式和水文过程，描述洪水的规模，季节性和位置的变化模式将提高我们对后果的理解，并为未来的洪水事件做好准备。在这项研究中，84雨量计和111波峰计横跨五个主要夏威夷群岛进行了分析，从1970年到2005年。我们估计的趋势，年最大日降雨量（RFmax）和年洪峰流量（PFmax）使用的Mann-Kendall检验和森氏斜率。随后，我们研究了PFmax和降雨之间的关系。然后，我们评估的时间转移相结合的循环分析与森的斜率。确定的主要趋势显示RFmax和PFmax降低（分别占所有量规的67%和61%）。夏威夷群岛的自然地理学（即，迎风对背风）对这两种趋势的贡献都很小。此外，PFmaxtrend不能完全归因于RFmaxtrend，并且在许多情况下，RFmax和PFmax并不同时发生。我们还发现，RFmax和PFmax的时间发生在早湿季在厄尔尼诺年和移动甚至更早，从1970年到2005年，可能是由于厄尔尼诺的变化。这些发现对评估洪水风险具有重要意义。我们的发现将有助于流域管理和洪水缓解，并可以提高下游社区和近岸环境的恢复力。
Flooding is a significant threat to life and property in Hawaiʻi. As climate warming continues to alter precipitation patterns and hydrological processes in the tropics, characterizing the shifting patterns in magnitude, seasonality, and location of floods would improve our understanding of the consequences and better prepare us for future flood events. In this study, 84 rain gauges and 111 crest gauges across five major Hawaiian Islands were analyzed from 1970 to 2005. We estimated trends in the annual maximum daily rainfall (RFmax) and the annual peak flow (PFmax) using the Mann-Kendall test and Senʻs slope. Subsequently, we examined the association between PFmaxand rainfall. Then, we assessed temporal shifting by combining circular analysis with Senʻs slope. The main identified trends showed decreases in RFmaxand PFmax(67% and 61% of all gauges, respectively). The physiography of the Hawaiian islands (i.e., windward vs. leeward) has little contribution to both trends. In addition, PFmaxtrend cannot be fully attributed to RFmaxtrend, and in many cases, RFmaxand PFmaxdid not occur coincidently. We also found the timing of RFmaxand PFmaxoccurred in early wet season during the El Niño years and shifted even earlier from 1970 to 2005, likely due to the change of El Niño. These findings have implications for assessing flood risk. Our finding will aid watershed management and flood mitigation, and can increase resilience of downstream communities and near-shore environments.