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The collapse of glacial, permafrost, and ice-rich moraine slopes in high-altitude mountainous areas not only threatens downstream residents and infrastructure but also displaces ice mass to lower and warmer elevations, accelerating glacial ablation to some extent. Despite being considered rare, ice-rich slopes collapse more frequently than commonly thought due to climate change. For example, two adjacent mountain glaciers in the Aru Range of the Tibetan Plateau, characterized by large volumes (68 × 106 m3 and 83 × 106 m3, respectively) and low surface slope angles (12.3° and 12.9°, respectively), collapsed surprisingly in 2016. While the mechanisms behind these collapses have garnered broad attention, the ability to quantitatively assess the instability of ice-rich slopes remains limited due to the complex interplay of multi-physical processes. Taking the Aru glacier collapses as reference cases, this paper presents a conceptual model, implemented through coupled thermo-hydro-mechanical simulation, to evaluate the stability of high-altitude ice-rich slopes due to climate change, rainfall and ice ablation. Results indicate that the methodology captures the effects of temperature change, rainfall and meltwater on the instability events well, demonstrating promising potential in evaluating potential collapse zones of ice-rich slopes similar to the Aru glaciers. Furthermore, the role of climate change in the well-known Aru events is demonstrated using a state-of-the-art global climate reanalysis dataset. Findings reveal that the increase in liquid water infiltrating the Aru glaciers since 2010 was a critical factor leading to the instability events. • A conceptual model is proposed to analyse the stability and collapse zones of ice-rich slopes. • The modelling elucidates the causes of twin collapses of the Aru glaciers. • Results contribute to ice-rich slope instability prediction and associated disaster risk management. [ABSTRACT FROM AUTHOR]

Glaciers, as the core part of the cryosphere, are very sensitive to climate change. As an indicator of glacier changes, the characteristics of glacier-originated rivers have profound significance to global climate change and local water resources. In this paper, the Mingyong River, a glacier-originated river replenished by groundwater, was selected to study the river hydrological cycle characteristics by integrating natural tracer radium isotopes with hydrochemical parameters. The results showed that there were significant differences in radium isotope activities and hydrochemical parameters between groundwater and river water, and the radium activities increased along the river, which reflected the fact that the river was supplied by groundwater seepage. We also found that the activity ratios of 224Ra/228Ra in river and groundwater were less than one unit, which indicated that the groundwater and river water circulated rapidly and that the radioactive equilibrium of short-time radium isotopes had not yet been reached. According to the geochemical behavior of radium in river water body, the mass balance equation of radium was established. 228Ra and 224Ra were used to estimate the groundwater seepage of different segments of the Mingyong River. The results demonstrated that the groundwater seepage fluxes calculated by 224Ra and 228Ra were similar and increased along the river from 123.12 to 657.68 m3 m−1 d−1. Our results have certain significance in revealing the characteristics of the local hydrological cycle and demonstrate that radium isotopes can be used as a tool to estimate the groundwater discharge of rivers in glacial environments. [Display omitted] • Estimated the groundwater seepage along a glacier originated river. • Ra isotopes mass balance model of the river is established. • Verified Ra isotopes is an effective tool in glacial area. [ABSTRACT FROM AUTHOR]