The seasonal dynamic changes of Tibetan glaciers have seen little prior investigation, despite the increase in geodetic studies of multi-year changes. This study compares seasonal glacier dynamics (“cold” and “warm” seasons) in the ablation zone of Parlung No. 4 Glacier, a temperate glacier in the monsoon-influenced southeastern Tibetan Plateau, by using repeat unpiloted aerial vehicle (UAV) surveys combined with Structure-from-Motion (SfM) photogrammetry and ground stake measurements. Our results showed that the surveyed ablation zone had a mean change of −2.7 m of ice surface elevation during the period of September 2018 to October 2019 but is characterized by significant seasonal cyclic variations with ice surface elevation lifting (+2.0 m) in the cold season (September 2018 to June 2019) but lowering (−4.7 m) in the warm season (June 2019 to October 2019). Over an annual timescale, surface lowering was greatly suppressed by the resupply of ice from the glacier’s accumulation area—the annual emergence velocity compensates for about 55% of surface ablation in our study area. Cold season emergence velocities (3.0 ± 1.2 m) were ~5-times larger than those observed in the warm season (0.6 ± 1.0 m). Distinct spring precipitation patterns may contribute to these distinct seasonal signals. Such seasonal dynamic conditions are possibly critical for different glacier responses to climate change in this region of the Tibetan Plateau, and perhaps further afield.

Debris-covered glaciers have contrasting melting mechanisms and climate response patterns if compared with debris-free glaciers and thus show a unique influence on the hydrological process. Based on high-resolution satellite images and unpiloted aerial vehicle surveys, this study investigated the dynamic changes of Zhuxi Glacier, a thick debris-covered glacier in the southeastern Tibetan Plateau. Our result shows that the whole glacier can be divided into the active regime and stagnant regime along the elevation of 3400 m a.s.l. The mean surface velocity of the active regime was 13.1 m yr⁻¹, which was five times higher than that of the stagnant regime. The surface-lowing rate of this debris-covered glacier reaches more than 1 m yr⁻¹ and displays an accelerating trend. The majority of ice loss concentrates around ice cliffs and supraglacial ponds, the ablation hotspots. These hotspots can be roughly classified into three types, including persistent, expanding, and shrinking patterns, at different dynamic regimes on the Zhuxi Glacier. With the evolution of these hotpots and glacier dynamic changes, the supraglacial ponds showed significant change, with the total number fluctuating from 15 to 38 and the total area increasing from 1128 m² to 95790 m² during the past decade. The recent exponential expansion of the proglacial lake and the significant downwasting of stagnant ice inside the dammed terminus moraine possibly trigger the glacial lake outburst flood and thus threaten the security of livelihoods and infrastructure downstream.

Debris-free and debris-covered glaciers are both extensively present in the southeastern Tibetan Plateau. High-precision and rigorous comparative observational studies on different types of glaciers help us to accurately understand the overall state of water resource variability and the underlying mechanisms. In this study, we used multi-temporal simultaneous UAV surveys to systematically explore the surface elevation change, surface velocity, and surface mass balance of two representative glaciers. Our findings indicate that the thinning rate in the debris-free Parlung No. 4 glacier UAV survey area was consistently higher than that in the debris-covered 24K glacier in 2020–2021 (−1.16 ± 0.03 cm/d vs. −0.36 ± 0.02 cm/d) and 2021–2022 (−0.69 ± 0.03 cm/d vs. −0.26 ± 0.03 cm/d). Moreover, the surface velocity of the Parlung No. 4 glacier was also consistently higher than that of the 24K glacier across the survey period, suggesting a more dynamic glacial state. The surface mass balance of the Parlung No. 4 glacier (2020–2021: −1.82 ± 0.09 cm/d; 2021–2022: −1.30 ± 0.09 cm/d) likewise outpaced that of the 24K glacier (2020–2021: −0.81 ± 0.07 cm/d; 2021–2022: −0.70 ± 0.07 cm/d) throughout the observation period, which indicates that the debris cover slowed the glacier’s melting. Additionally, we extracted the melt contribution of the ice cliff area in the 24K glacier and found that the melt ratio of this ‘hotspot’ area ranged from 10.4% to 11.6% from 2020 to 2022. This comparative analysis of two representative glaciers provides evidence to support the critical role of debris cover in controlling surface elevation changes, glacier dynamics, and surface mass balance.

The Third Pole region contains vast glaciers, and changes in these glaciers profoundly affect the lives and development of billions of people. Therefore, accurate glacier monitoring in this region is of great scientific and practical significance. Unmanned Aerial Vehicles (UAVs) provide high-resolution observation capabilities and flexible deployment options, effectively overcoming certain limitations associated with traditional in situ and satellite remote sensing observations. Thus, UAV technology is increasingly gaining traction and application in the glaciology community. This review systematically analyzed studies involving UAV technology in Third Pole glaciology research and determined that relevant studies have been performed for a decade (2014–2024). Notably, after 2020, the number of relevant manuscripts has increased significantly. Research activities are biased toward the use of rotary-wing UAVs (63%) and ground control point (GCP) correction methods (67%). Additionally, there is strong emphasis on analyzing glacier surface elevation, surface velocity, and landform evolution. These activities are primarily concentrated in the Himalayan region, with relatively less research being conducted in the western and central areas. UAV technology has significantly contributed to glaciology research in the Third Pole region and holds great potential to enhance the monitoring capabilities in future studies.

The thermal environment of high-elevation valley cities is jointly shaped by urbanization and complex geographic settings. Using Landsat and MODIS data from 2000 to 2025, annually varying built-up-area boundaries, and elevation-constrained rural references, we characterized the diurnal and seasonal patterns of the surface urban heat island (SUHI) in Nyingchi, Tibet Autonomous Region, China, and used an XGBoost model with out-of-fold SHAP interpretation to examine predictive associations with summer daytime surface thermal anomalies in 2025. The results showed that, since 2000, the urban built-up area of Bayi District expanded from 2.15 to 12.34 km². Daytime SUHI was strongest in summer (5.24 °C) and was clearly distinct from that in other seasons, whereas nighttime SUHI remained a weak warming signal in all four seasons. A conventional buffer reference that included cooler mountain slopes overestimated summer daytime SUHI by 4.00 °C relative to the elevation-constrained reference, indicating that rural-reference definition is decisive in this terrain. Spatial cross-validation of the XGBoost model yielded an R² of 0.764; moisture and vegetation variables were associated with lower predicted anomalies, whereas built-up status was associated with higher predicted anomalies. These findings identify a pronounced diurnal-seasonal asymmetry in Nyingchi’s SUHI and provide a basis for terrain-aware thermal-environment assessment; the machine-learning associations are not interpreted as causal intervention effects.

The Sedongpu Valley has experienced repeated ice–rock avalanches, glacier detachments, and related hazards, but the long-term vegetation trajectory in this hazard-affected outlet landscape remains poorly documented. To document vegetation changes in relation to the published hazard sequence, quality-controlled Landsat and Sentinel-2 observations from 2015 to 2025 were used to reconstruct annual NDVI, EVI, and SAVI for a 3.41 km² outlet analysis grid. Published hazard and elevation-change studies and ERA5-Land data provided environmental context. The largest observed annual decline occurred during 2017–2018: median NDVI decreased from 0.845 to 0.688, while low-NDVI area increased from 0.05 to 0.82 km². Among 977 fixed pixels that crossed from NDVI ≥ 0.30 in 2017 to <0.30 in 2018, 25.8% were again at or above the threshold in 2025, following a non-monotonic annual trajectory. Alternative thresholds of 0.25 and 0.35 gave endpoint proportions of 25.4% and 25.9%. Mean paired-pixel NDVI change over 2015–2025 remained −0.137. The July 2017 acquisition introduces seasonal uncertainty, and concurrent climate correlations do not isolate causal effects. The results document spatially uneven, incomplete spectral recovery within a landscape affected by repeated glacier-related hazards and subsequent geomorphic reworking.