Summary The areas of glacial lakes in the Himalayas continue to increase alarmingly due to global warming with consequent risk of glacial lake outburst flood (GLOF). The outburst is most common for moraine-dammed lakes as a result of a failure of the dam by overtopping and erosion or piping due to seepage. In the present context, GLOF events, especially for the moraine dam failure process needs to be predicted to assess the drastic and detrimental impacts on the downstream river valley. This study focuses on validating an integrated model for simulating the failure of moraine dam by overtopping and erosion using a coupled numerical simulation model. The proposed numerical methodology is validated with the data from experiments in laboratory scale physical models. The results of the model are compared for both the erosional profiles during collapse of the dam and the resulting outflowing flood hydrograph. The primary finding is that the moraine dam height and the volume of the lake upstream of the dam are the most sensitive parameters influencing the GLOF peak. The model is also applied to the field problem of the Tangjiashan lake outburst and dam failure and shows reasonably good agreement with observations. The validated model is also run for the South Lhonak glacial lake in the Sikkim Himalayas, India to obtain the probable flood hydrograph in case of failure of the moraine dam.

中文翻译：

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冰碛溃坝和冰湖溃决洪水的物理和数值模型

总结 由于全球变暖，喜马拉雅山冰川湖的面积继续以惊人的速度增加，随之而来的还有冰川湖溃决洪水 (GLOF) 的风险。溃坝最常见于冰碛堰塞湖，原因是水坝因溢流和侵蚀或管道渗漏造成的溃坝。在目前的情况下，需要预测 GLOF 事件，尤其是冰碛大坝的溃坝过程，以评估对下游河谷的剧烈和不利影响。本研究的重点是验证一个综合模型，用于使用耦合数值模拟模型来模拟因漫溢和侵蚀造成的碛坝破坏。所提出的数值方法通过实验室规模物理模型中的实验数据进行了验证。对大坝倒塌期间的侵蚀剖面和由此产生的外流洪水过程线对模型的结果进行了比较。主要发现是，碛坝高度和坝上游湖泊体积是影响 GLOF 峰值的最敏感参数。该模型还应用于唐家山湖溃决和大坝溃决的现场问题，并显示出与观测结果相当好的一致性。验证模型还用于印度锡金喜马拉雅山的南 Lhonak 冰川湖，以获得在碛坝发生故障时可能的洪水过程线。该模型还应用于唐家山湖溃决和大坝溃决的现场问题，并显示出与观测结果相当好的一致性。验证模型还用于印度锡金喜马拉雅山的南 Lhonak 冰川湖，以获得在碛坝发生故障时可能的洪水过程线。该模型还应用于唐家山湖溃决和大坝溃决的现场问题，并显示出与观测结果相当好的一致性。验证模型还用于印度锡金喜马拉雅山的南 Lhonak 冰川湖，以获得在碛坝发生故障时可能的洪水过程线。