Reducing uncertainty with flood frequency analysis: The contribution of paleoflood and historical flood information
Reducing uncertainty with flood frequency analysis: The contribution of paleoflood and historical flood information
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DOI：
10.1002/2016wr019959
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发表时间：
2017-03-01
影响因子：
5.4
通讯作者：
Macklin, Mark
中科院分区：
文献类型：
--
作者：
Lam, Daryl;Thompson, Chris;Macklin, Mark
使用流计，历史和古洪水记录的组合，以延长极端洪水记录已被证明是有用的，在提高洪水频率分析（FFA）。该方法通常应用于具有悠久历史记录和/或适合从静水沉积物（SWDs）重建古森林的河流环境的地方。然而，世界上许多地区既没有广泛的历史信息，也没有适合SWD保护和古洪水重建的基岩峡谷。这项研究表明，从亚热带澳大利亚的封闭，半冲积渠道，如macrochannels提供相对稳定的边界在1000-2000年的时间段和保存SWDs使古植被重建和纳入FFA。FFA的三个网站在亚热带澳大利亚的历史和古森林数据，使用贝叶斯推理方法的整合显示出显着减少与洪水分位数的估计流量的不确定性。与1%年超额概率（AEP）洪水的估计流量相关的不确定性降低了50%以上。此外，可能的通道内边界变化的敏感性分析表明，FFA是不显着影响任何相关的变化，通道容量。因此，更大范围的通道类型可以用于可靠的古植被重建，通过评估插入冲积单元的稳定性，从而增加FFA可用的时间数据的数量。不确定性的减少，特别是在1% AEP设计洪水的预测，将改善洪水风险规划和管理的地区有限的时间洪水数据。
Using a combination of stream gauge, historical, and paleoflood records to extend extreme flood records has proven to be useful in improving flood frequency analysis (FFA). The approach has typically been applied in localities with long historical records and/or suitable river settings for paleoflood reconstruction from slack-water deposits (SWDs). However, many regions around the world have neither extensive historical information nor bedrock gorges suitable for SWDs preservation and paleoflood reconstruction. This study from subtropical Australia demonstrates that confined, semialluvial channels such as macrochannels provide relatively stable boundaries over the 1000-2000 year time period and the preserved SWDs enabled paleoflood reconstruction and their incorporation into FFA. FFA for three sites in subtropical Australia with the integration of historical and paleoflood data using Bayesian Inference methods showed a significant reduction in uncertainty associated with the estimated discharge of a flood quantile. Uncertainty associated with estimated discharge for the 1% Annual Exceedance Probability (AEP) flood is reduced by more than 50%. In addition, sensitivity analysis of possible within-channel boundary changes shows that FFA is not significantly affected by any associated changes in channel capacity. Therefore, a greater range of channel types may be used for reliable paleoflood reconstruction by evaluating the stability of inset alluvial units, thereby increasing the quantity of temporal data available for FFA. The reduction in uncertainty, particularly in the prediction of the 1% AEP design flood, will improve flood risk planning and management in regions with limited temporal flood data.