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PUBLICATION SPOTLIGHT
| Cheng et al. 2025
The central Himalayas is a land of towering glacier-clad mountains, a cold, high-elevation portion of the Tibetan Plateau, or “third pole.” Warming temperatures associated with global climate change have recently accelerated glacier retreat in the region resulting in an expansion of glacial lakes. This shift has increased the risk of disasters caused by ice and rock avalanches and glacial lake outburst floods. Using Landsat and Sentinel-2 data within Google Earth Engine, Cheng et al. have documented the shifts in geographical distribution, growth, and flood risks associated with these glacial lakes between 1990 and 2020. Their innovative methodology uses the enhanced normalized difference water index and dynamic thresholding to define glacial lake boundaries automatically and precisely, mitigating problems associated with cloud cover and other data noise sources. Findings show that most glacial lakes in this region are on the China-Nepal border at an elevation of 3600–5900 meters. There has been a proliferation of small glacier lake formation since the 1990s, with 847 new lakes formed by glacial meltwater. Flood events caused by glacial lakes outbursts (which occur most frequently in June and August and have been increasing since 1950) show an accelerated incidence rate since 1990. The researchers found a correlation between the rate of glacial lake expansion and the likelihood of a flooding event—an important hazard assessment variable that can inform the development of mitigation strategies to protect downstream populations.
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