Recently, the project team of Alliance of International Science Organizations (ANSO)-Chinese Academy of Sciences (CAS) Joint Research Project entitled “Numerical simulation and risk analysis of landslide hazard chains in high-mountain Asia considering the effects of global climate change” (ANSO-CR-KP-2021-07) has made great progress on the research of glacier lake outburst floods caused by waves induced by ice/rock calving. The research paper, one of the major outcomes, has been published on Engineering Geology on June 2022.
As a result of global climate change, glacier lakes are rapidly expanding around the world, increasing the risk of outburst floods. These floods can be triggered when rock or rock-ice avalanches, or glaciers abruptly collapse onto glacier lakes thereby generating massive waves which destabilize their natural barriers. At present, there is limited research on the mechanisms of waves overtopping natural dams. Therefore, the models which predict the volume of overtopping water, a key parameter needed for the mitigation of glacier lake outburst hazards, remain unavailable. In response to this problem, Prof. Gordon G.D. Zhou and his team carried out numerous experiments and numerical simulations aimed to evaluate the key parameters that control the overtopping of waves having different wave heights. An empirical formula was derived, based on the geometrical similarities of the overtopping process and the run up of fluids on rigid inclinations, that allow for the rapid estimation of overtopping volumes and hence the impact range of glacial lake outburst floods. This is of great significance for the prediction of glacial lake outburst flood disasters.
This work was made possible by the support of ANSO and through the cooperation with the Research Institute for Geo-Hydrological Protection, National Research Council of Italy (IRPI-CNR), the Technical University of Munich, and the International Centre for Integrated Mountain Development (ICIMOD). This research has also greatly benefitted from the online technical seminar on "Typical Cases of Glacial Lake Outbursts Induced by Rock/Ice Calving in the Hindu Kush-Himalaya Mountains and Alps Regions", which was conducted to provide the technical support for accurate estimation of GLOFs hazards along the Belt and Road regions. This research is also supported by the China-Germany Mobility Programme of the National Natural Science Foundation of China (M-0145).
(a) Schematic diagram of wave run-up (blue dashed profile) and overtopping (red solid profile) processes highlighting their geometric similarities.
(b) Comparison of overtopping wave profiles observed from experiments (top) and as obtained from numerical simulations (bottom).
Comparison of predicted and measured values of the (c) proportionality coefficient and (d) the overtopping volume.
Citation:Lu, X., Zhou, G. G., Cui, K. F., Tang, H., & Xie, Y. (2022). Overtopping volume of impulse waves in glacier lakes: Experimental and numerical investigation using rigid dams. Engineering Geology, 106763. DOI: https://doi.org/10.1016/j.enggeo.2022.106763
Source: LU Xueqiang, Institute of Mountain Hazards and Environment (IMHE), Chinese Academy of Sciences