Abstract Climate change is expected to significantly alter river hydrological regimes throughout the world, affecting water resources and the frequency of floods and droughts. The objectives of this study were to determine the impacts of climate change and sea level rise on streamflow and floodplain inundation in the subtropical Logan-Albert catchment, Australia. An ensemble of 11 high-resolution climate models forced under high (Representative Concentration Pathway 8.5 - RCP8.5) and intermediate-emission (RCP4.5) scenarios was applied. There was considerable variation from the model ensemble result in projections of major flooding events at 5 and 100-year average recurrence intervals (ARIs). The largest events (100-year ARI) tended towards an increase, whereas the smallest (5-year ARI) tended towards a decrease. Floodplain inundation from a 100-year ARI event increased in all simulations and inclusion of sea level rise resulted in increased floodplain inundation area nearly doubling by the end of the century, which has substantial implications for flood risk. Our study highlights the non-linear nature of climate change impacts on streamflow and floodplain inundation, demonstrating the need for a comprehensive assessment at the floodplain scale when informing preparedness for future flooding events.

中文翻译：

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气候变化对沿海亚热带集水区河流和洪泛区淹没的影响

摘要 气候变化预计将显着改变世界各地的河流水文状况，影响水资源和洪水和干旱的频率。本研究的目的是确定气候变化和海平面上升对澳大利亚亚热带 Logan-Albert 流域的河流和洪泛区淹没的影响。应用了在高（代表性浓度路径 8.5 - RCP8.5）和中等排放（RCP4.5）情景下强制执行的 11 个高分辨率气候模型的集合。在 5 年和 100 年平均复发间隔 (ARI) 的主要洪水事件预测中，模型集合结果存在相当大的差异。最大的事件（100 年 ARI）趋于增加，而最小的事件（5 年 ARI）趋于减少。在所有模拟中，100 年 ARI 事件造成的洪泛区淹没增加，并且包括海平面上升导致洪泛区淹没面积增加，到本世纪末几乎翻了一番，这对洪水风险产生了重大影响。我们的研究强调了气候变化对河流流量和洪泛区淹没影响的非线性性质，表明在为未来洪水事件做好准备时需要在洪泛区范围内进行全面评估。