Search Results (49)

Climate-induced lake expansion on the Tibetan Plateau (TP) has led to two distinct hazard types: outburst floods and passive inundation. However, the divergent driving mechanisms behind these hazards remain insufficiently understood. This study analyzes the spatiotemporal trends of 1352 non-glacial lakes (>1 km²) on the TP from 2014 to 2023 using high-resolution Gaofen-1 (GF-1) and Gaofen-2 (GF-2) imagery. By integrating geomorphic analysis with hazard mechanisms, we screened and categorized lakes prone to outburst floods and inundation using a classification and assessment framework proposed in this study. The results indicate that the net area of these lakes expanded by 2839.53 km² (6.07%), with the Inner TP Basin contributing the largest absolute area gain (1960.60 km²). We identified 21 potentially hazardous lakes (10 outburst-prone and 11 inundation-prone) and systematically categorized them by risk level. Field investigations of high-risk candidates, such as Rulei Co and Xiao Qaidam Lake, validated the accuracy of the hazard classification and risk assessment methodology. Preliminary attribution analysis further suggests that the two hazard types may be associated with distinct climatic factors. Overall, this study provides a scientific basis for disaster mitigation and lake management on the TP. Full article

The retreat of glaciers has accelerated the expansion of glacial lakes, heightening the risk of outburst floods. Satellite remote sensing provides a crucial means for monitoring these lakes. Yet, artifacts caused by cloud cover and shadows inevitably persist even after preprocessing, compromising the reliability of large-scale automated analyses. However, the conventional approach views such data noise merely as an obstacle to be removed. The critical research gap lies in the lack of systematic methods to identify and filter out anomalies arising from unavoidable interferences actively. To address this, we propose a Gaussian process anomaly detection method that incorporates features of glacial lake evolution. By modeling how lakes change over time and establishing confidence intervals, this study effectively detects anomalies in automatically identified glacial lakes from remote sensing imagery. Analysis of typical Himalayan glacial lakes demonstrates that this method achieves an F1-score of 0.95, significantly improving the precision of remote sensing datasets. Overall, this research provides valuable technical support for developing high-quality glacial lake datasets and for automating lake monitoring. Full article

Lakes account for approximately 87% of the Earth’s surface water resources and serve as sensitive indicators of climate and environmental change. Understanding how lake areas respond to climate change across different elevation gradients is crucial for guiding sustainable water resource management in Xinjiang. We utilized Landsat series remote sensing imagery (1990–2023) on the Google Earth Engine (GEE) platform to extract the temporal dynamics of natural lakes larger than 10 km² in Xinjiang, China (excluding reservoirs). We analyzed the relationships between lake area dynamics, climatic factors, and human activities to assess the sensitivity of lakes at different altitudinal zones to environmental change. The results showed that (1) the total area of Xinjiang lakes increased by 1188.36 km² over the past 34 years, with an average annual area of 5998.54 km²; (2) plain lakes experienced fluctuations, reaching their maximum in 2000 and their minimum in 2015, alpine lakes peaked in 2016, and plateau lakes continued to expand, with the maximum recorded in 2020 and the minimum in 1995; and (3) human activities such as urban and agricultural water use were the primary causes of shrinking plain lakes, while an increased PET accelerates evaporation, alpine lakes were influenced by both climate variability and human disturbance, and plateau lakes were highly sensitive to climate change, with rising temperatures increasing snowmelt and glacial runoff into lakes, which were the main drivers of their expansion. These findings highlight the importance of incorporating elevation-specific lake responses into climate adaptation strategies and sustainable water management policies in arid regions. Full article

Glacial Lake Outburst Floods (GLOFs) have emerged as a critical threat to high-mountain communities and ecosystems, driven by accelerated glacier retreat and lake expansion under climate change. This review synthesizes advancements in remote sensing technologies and methodologies for GLOF monitoring, risk assessment, and mitigation. Through a Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA)-guided systematic literature review and bibliometric analysis of studies from 2010 to 2025, we evaluate the transformative role of remote sensing in overcoming traditional field-based limitations. Central to this review is the exploration of multi-sensor data fusion for high-resolution lake dynamics mapping, machine learning algorithms for predictive risk modelling, and hydrodynamic simulations for flood propagation analysis. This review underscores the importance of these technologies in improving GLOF risk assessments and supporting early warning systems, which are crucial for safeguarding vulnerable high-mountain communities. It addresses existing challenges, such as data integration and model calibration, and advocates for collaborative efforts between scientists, policymakers, and local stakeholders to translate technological advancements into effective mitigation strategies, ensuring the sustainability of these at-risk regions. Full article

The remarkable expansion of lake areas across the Changtang Plateau (CTP, located in the central Tibetan Plateau) since the late 1990s has drawn considerable scientific interest, presenting a striking contrast to the global decline in natural lake water storage observed during the same period. This study systematically investigates the mechanisms underlying lake area variations on the CTP by integrating glacierized area changes derived from the Google Earth Engine (GEE) platform with atmospheric circulation patterns from the ERA5 reanalysis dataset. Our analysis demonstrates that the limited glacier coverage on the CTP exerted significant influence only on glacial lakes in the southern region (r = −0.65, p < 0.05). The widespread lake expansion across the CTP predominantly stems from precipitation increases (r = 0.74, p < 0.01) associated with atmospheric circulation changes. Enhanced Indian summer monsoon (ISM) activity facilitates anomalous moisture transport from the Indian Ocean to the southwestern CTP, manifesting as increased specific humidity (Qa) in summer. Simultaneously, the weakened westerly jet stream reinforces moisture convergence across the CTP, driving enhanced annual precipitation. By coupling glacier coverage variations with atmospheric processes, this research establishes that precipitation anomalies rather than glacial meltwater primarily govern the extensive lake expansion on the CTP. These findings offer critical insights for guiding ecological security strategies and sustainable development initiatives on the CTP. Full article

The Ross Sea I glaciation, marked by the northward advance of the Ross Ice Sheet (RIS) in the Ross Sea, east Antarctica, corresponds with the last major expansion of the West Antarctic Ice Sheet during the last glacial period. During its advance, the RIS was grounded along the southern Victoria Land coast, completely blocking the mouths of several of the McMurdo Dry Valleys (MDVs). Several authors have proposed that very large paleolakes, proglacial to the RIS, existed in many of the MDVs. Studies of these large paleolakes have been key in the interpretation of the regional landscape, climate, hydrology, and glacier and ice sheet movements. By far the most studied of these large paleolakes is Glacial Lake Washburn (GLW) in Taylor Valley. Here, we present a comprehensive review of literature related to GLW, focusing on the waters supplying the paleolake, signatures of the paleolake itself, and signatures of past glacial movements that controlled the spatial extent of GLW. We find that while a valley-wide proglacial lake likely did exist in Taylor Valley during the early stages of the Ross Sea I glaciation, during later stages two isolated lakes occupied the eastern and western sections of the valley, confined by an expansion of local alpine glaciers. Lake levels above ~140 m asl were confined to western Taylor Valley, and major lake level changes were likely driven by RIS movements, with climate variables playing a more minor role. These results may have major implications for our understanding of the MDVs and the RIS during the Ross Sea I glaciation. Full article

The Sikkim region of the Eastern Himalayas is highly susceptible to Glacial Lake Outburst Floods (GLOFs), a risk that has increased significantly due to rapid glacial retreat driven by climate change in recent years. This study presents a comprehensive evaluation of GLOF susceptibility in Sikkim, employing Analytic Hierarchy Process (AHP) and Fuzzy Analytic Hierarchy Process (FAHP) models. Key factors influencing GLOF vulnerability, including lake volume, seismic activity, precipitation, slope, and proximity to rivers, were quantified to develop AHP and FAHP based susceptibility maps. These maps were validated using Receiver Operating Characteristic (ROC) curves, with the AHP method achieving an Area Under the Curve (AUC) of 0.92 and the FAHP method scoring 0.88, indicating high predictive accuracy for both models. A comparison of the two approaches revealed distinct characteristics, with FAHP providing more granular insights into moderate-risk zones, while AHP offered stronger predictive capability for high-risk areas. Our results indicated that the expansion of glacial lakes, particularly over the past three decades, has heightened the potential for GLOFs, highlighting the urgent need for continuous monitoring and adaptive risk mitigation strategies in the region. This study, in addition to enhancing our understanding of GLOF risks in Sikkim, also provides a robust framework for assessing and managing these risks in other glacial regions worldwide. Full article

Maritime glaciers in the southeastern Tibetan Plateau (SETP) are particularly sensitive to changes in climate, and their changes directly and severely affect regional water security and glacier-related hazards. Given their large societal importance, a better understanding of the mass balance of maritime glaciers in the SETP, a key variable for characterizing the state of glacier health, is of great scientific interest. In this review, we synthesize in situ, satellite-based observations and simulations that present an overall accelerating negative mass balance of maritime glaciers in the SETP in recent decades. We hereby highlight a significant spatiotemporal difference in the mass balance of maritime glaciers across the SETP and investigate the drivers of the accelerated mass loss of these glaciers in recent years. We find that accelerated glacier mass loss agrees with the variabilities in temperatures rising and precipitation decreasing at regional scales, as well as the spatial patterns of widespread melt hotspots (e.g., thin debris, ice cliffs, supraglacial ponds, and surface streams), the expansion of glacial lakes, enlarged ice crevasses, and frequent ice avalanches. Finally, the challenges of the mass balance study of maritime glaciers and future perspectives are proposed. Our review confirms the urgent need to improve the existing glacier inventory and establish comprehensive monitoring networks in data-scarce glacierized catchments, and it suggests paying particular attention to the development of glacier mass-balance models that coupe multiple physical processes at different interfaces to predict the status of maritime glaciers and their responses to climate change. This study can inform the sustainable management of water resources and the assessment of socio-economic vulnerability due to glacier-related hazards in the SETP and its surroundings in the context of marked atmospheric warming. Full article

Lake-terminating glaciers are among the most severely retreating glacier types in high mountain areas. However, the characteristic of being covered by glacial lakes after retreat makes it hard to estimate their actual ice loss in recent years, as does the contribution of different parts in ice loss, which leads to significant obstacles not only in evaluating solid water resources but understanding inter-relationships between glacial ice and glacial lakes. This study presents a detailed investigation of Jiongpu Co, one of the biggest glacial lakes in the Tibetan Plateau, including its bathymetry and area evolution. The ice loss in the last two decades was analyzed using a multisource DEM dataset. The main results showed that from 1976 to 2021, Jiongpu Co had expanded from 1.19 ± 0.09 km² to 5.34 ± 0.07 km². The volume of Jiongpu Co showed a surprising increment from 0.09 ± 0.004 Gt to 0.66 ± 0.03 Gt from 1976 to 2021, leading to a subaqueous equivalent ice loss of 0.32 ± 0.01 Gt water from 2000 to 2020 and resulting in an underestimated ice loss of 0.06 Gt, 19% compared with previous evaluations. The total ice loss of the Jiongpu glacier was 1.52 ± 0.37 Gt from 2000 to 2020, and more than 1/3 ice loss was related to lake expansion (0.32 ± 0.01 Gt underwater, 0.19 ± 0.02 Gt above water). This study makes a further contribution to the understanding of ice loss in the complicated system of lake-terminating glaciers. Full article

The Antarctic photopsychrophile, Chlamydomonas priscui UWO241, is adapted to extreme environmental conditions, including permanent low temperatures, high salt, and shade. During long-term exposure to this extreme habitat, UWO241 appears to have lost several short-term mechanisms in favor of constitutive protection against environmental stress. This study investigated the physiological and growth responses of UWO241 to high-light conditions, evaluating the impacts of long-term acclimation to high light, low temperature, and high salinity on its ability to manage short-term photoinhibition. We found that UWO241 significantly increased its growth rate and photosynthetic activity at growth irradiances far exceeding native light conditions. Furthermore, UWO241 exhibited robust protection against short-term photoinhibition, particularly in photosystem I. Lastly, pre-acclimation to high light or low temperatures, but not high salinity, enhanced photoinhibition tolerance. These findings extend our understanding of stress tolerance in extremophilic algae. In the past 2 decades, climate change-related increasing glacial stream flow has perturbed long-term stable conditions, which has been associated with lake level rise, the thinning of ice covers, and the expansion of ice-free perimeters, leading to perturbations in light and salinity conditions. Our findings have implications for phytoplankton survival and the response to change scenarios in the light-limited environment of Antarctic ice-covered lakes. Full article

Vegetation dynamics data since the Last Glacial Maximum (LGM) are essential for our understanding of ecosystem shifts and vegetation responses to climate change. Here, we present a pollen record covering the last 25,000 years from Lake Fuxian in central Yunnan, southwest China. Our study shows seven stages of vegetation dynamics since the LGM: The early LGM (stage 7 of 25,000–21,200 cal. a BP) witnessed less dense regional vegetation dominated by pine forests, evergreen broadleaved forests (EBFs), deciduous broadleaved forests (DBFs), montane hemlock forests, and fir/spruce forests. The late LGM (stage 6 of 21,200–17,500 cal. a BP) saw an expansion of grasslands, wetlands, and montane fir/spruce forests as well as a shrinkage of EBFs and DBFs. During the last deglaciation (stage 5 of 17,500–13,300 cal. a BP), dense regional vegetation was dominated by EBFs as well as deciduous oak and alder forests. The densest regional vegetation occurred in stage 4 of 13,300–11,200 cal. a BP, roughly equal to the Younger Dryas Chron, when pine forests, DBFs, EBFs, grasslands, and wetlands grew in the Lake Fuxian catchment. During the early to mid-Holocene (stage 3 of 11,200–5000 cal. a BP), dense regional vegetation was dominated by sweetgum forests, in addition to some pine forests and EBFs. After 5000 cal. a BP, the regional vegetation density became lower and lower, and forests became thinner and thinner. Pine forests expanded to their maximum of the entire sequence in stage 2 of 5000–2500 cal. a BP. A big deforestation event occurred in stage 1 (the last 2500 years), when grasslands, wetlands, and cultivated vegetation dominated regional vegetation in the catchment of Lake Fuxian. The regional vegetation since the LGM in the catchment of Lake Fuxian also experienced six major transitions, five centennial shift events, and one big large-scale and long-term deforestation event. These resulted from the responses of regional vegetation to climate changes during the LGM, last deglaciation, and early–mid-Holocene, as well as human influence in the late Holocene. The vegetation density since the LGM has changed with the 25° N summer insolation. Full article

Ecological records from before and after the creation of natural parks are valuable for informing conservation and management but are often unavailable. High-resolution paleoecological studies may bridge the gap and provide the required information. This paper presents a 20th-century subdecadal reconstruction of vegetation and landscape dynamics in a national park of the Pyrenean highlands. The park lands had traditionally been used for cultivation, extensive grazing, forest exploitation, and hydroelectricity generation following the damming of numerous glacial lakes. A significant finding is that forests have dominated the landscape, with negligible changes in composition, and only experienced fluctuations in forest cover, influenced by both climatic and anthropogenic factors. The creation of the park (1955) and the initial restrictions on forest exploitation did not significantly affect vegetation cover or composition. Major forest expansion did not occur until several decades later, 1980, when the park was enlarged and forest exploitation was further restricted. This expansion peaked in the 1990s, coinciding with a warming trend and a decrease in fire incidence, before declining due to warmer and drier climates. This decline was coeval with the ongoing global forest dieback and may be exacerbated by the predicted global warming in this century, which could also increase fire incidence due to dead-wood accumulation. Currently, the main threats are global warming/drying, fire, and tourism intensification. Similar high-resolution paleoecological records in protected areas are globally scarce and would be capable in providing the long-term ecological scope required to properly understand forest dynamics and optimize conservation measures. Full article

In High Mountain Asia, most glaciers and glacial lakes have undergone rapid variations throughout changes in the climate. Unlike land-terminating glaciers, lake-terminating glaciers show rapid shrinkage due to dynamic interactions between proglacial lakes and glacier dynamics. In this study, we conducted a detailed analysis of the changes in the surface elevation, velocity, and especially frontal ablation on Jiongpu Co lake-terminating glacier. The results show that the Jiongpu Co glacier has twice as much negative mass balance compared to other glaciers, and the annual surface velocity has anomalously increased (3.6 m a⁻¹ per decade) while other glaciers show a decreased trend. The frontal ablation fraction in the net mass loss of the Jiongpu Co glacier increased from 26% to 52% with the accelerated expansion of the proglacial lake. All available evidence indicates the presence of positive feedback between the proglacial lake and its host glacier. Our findings highlight the existence of proglacial lake affects the spatial change patterns of the lake-terminating glacier. Furthermore, the ongoing enlargement of the lake area amplifies the changes associated with the evolution of the lake-terminating glacier. Full article

The over 2200 lakes of Mongolia are generally poorly studied, particularly the glacial lakes. This overview study presents a classification of the glacial lakes based on tectonic-geological and geomorphological dynamics. Selected representative lakes are described using results from fieldwork and satellite image analysis, including bathymetry, paleoshorelines, and recent lake-level fluctuations between 1987 and 2020. Generally, lake levels dropped from the early Holocene until recently, with the onset of the climate change-driven glacier recession that has resulted in lake-level rises and area expansion in almost all moraine-dammed, tongue-basin, and ice-contact lakes. In contrast, endorheic lakes have mainly been shrinking for the past forty years because of an increase in air temperature and evaporation rates and the effects of an intensifying water use within the catchment for irrigation, mining, and hydroelectric energy production in the form of dams. The creation of a lake monitoring system based on an in-depth inventory is recommended. Full article

The glacial lakes in the Southeastern Qinghai–Tibet Plateau (SEQTP) have undergone dramatic expansion in the context of global warming, leading to several glacial lake outburst floods (GLOFs) disasters. However, there is a gap and incompleteness in glacial lake inventories across this area due to the heavy cloud cover. In this study, an updated and comprehensive glacial lake inventory was produced by object-based image analysis (OBIA) and manual vectorization based on the Sentinel-1 SAR and Sentinel-2 MSI images acquired in 2022. Detailed steps regarding the OBIA were provided, and the feature set of Sentinel-1 SAR images suitable for extracting glacial lakes was also determined in this paper. We found that the mean combination of ascending-orbit and descending-orbit images is appropriate for mapping glacial lakes. VV-polarized backscattering coefficients from ascending-orbit achieved a better performance for delineating glacial lakes within the study area. Moreover, the distribution of glacial lakes was characterized in terms of four aspects: size, type, elevation, and space. There were 3731 glacial lakes with a total area of 1664.22 ± 0.06 km² in the study area; most of them were less than 0.07 km². Ice-contacted lakes were primarily located in the Palongzangbo basin (13.24 ± 0.08 km²). Nyang Qu basin had the most abundant glacial lake resources (2456 and 93.32 ± 0.18 km²). A comparison with previously published glacial lake datasets demonstrated that our dataset is more complete. This inventory is useful for evaluating water resources, studying glacier–glacial lake interactions, and assessing GLOFs’ susceptibility in the SEQTP. Full article