Climate change currently affects the resilience and aquatic ecosystem. Climate change alters rainfall patterns which have a great impact on river flow. Annual flooding is an important hydrological characteristic of the Mekong River Basin (MRB) and it drives the high productivity of the ecosystem and biodiversity in the Tonle Sap floodplain and the Mekong Delta. This study aims to assess the impacts of climate change on river flow in the MRB and flood inundation in the Lower Mekong Basin (LMB). The changing impacts were assessed by a two-dimensional rainfall-runoff and inundation model (RRI model). The present climate (1979–2003) and future projected climate (2075–2099) datasets from MRI-AGCM3.2H and MRI-AGCM3.2S models were applied with a linear scaling bias correction method before input into the RRI model. The results of climate change suggested that flood magnitude in the LMB will be severer than the present climate by the end of the twenty-first century. The increment of precipitation between 6.6 and 14.2% could lead to increase extreme flow (Q₅) 13–30%, peak inundation area 19–43%, and peak inundation volume 24–55% in the LMB for ranging of Representative Concentration Pathways (RCP) and sea surface temperature (SST) scenarios while there is no significant change on peak flood timing.

中文翻译：

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利用高分辨率AGCM输出评估湄公河下游地区气候变化对洪水泛滥的影响

气候变化目前影响着复原力和水生生态系统。气候变化改变了降雨模式，这对河流流量产生了巨大影响。年度洪水是湄公河流域（MRB）的重要水文特征，它驱使洞里萨湖泛滥平原和湄公河三角洲的生态系统和生物多样性的生产力提高。这项研究旨在评估气候变化对MRB中的河流流量和下湄公河流域（LMB）洪水泛滥的影响。通过二维降雨径流和淹没模型（RRI模型）评估影响的变化。从MRI-AGCM3.2H和MRI-AGCM3.2S模型获得的当前气候（1979-2003）和未来气候预测（2075-2099）数据集在输入RRI模型之前应用了线性比例偏差校正方法。气候变化的结果表明，到21世纪末，LMB的洪水强度将比当前的气候更为严峻。降水量在6.6％至14.2％之间的增加可能导致极端流量增加（Q₅）在代表浓度路径（RCP）和海表温度（SST）情景范围内，LMB的13–30％，峰值淹没面积19–43％和峰值淹没量24–55％，而洪水高峰时间。