In recent decades, significant global warming has driven heterogeneous glacier thinning and retreat across High Mountain Asia (HMA), leading to the formation of new glacial lakes and the expansion of existing ones. These changes, along with their potential socio-economic impacts, have drawn growing attention from both the public and scientific communities. This study investigates glacial lake formation and expansion in the Hunza Valley, located in the western Karakoram, northern Pakistan—a region known for its high frequency of glacial lake outburst floods (GLOFs) that pose recurrent threats to downstream communities, particularly along the China-Pakistan Economic Corridor (CPEC). Using multi-temporal Landsat imagery from 1990 to 2021, we mapped and quantified changes in glacial lakes, revealing significant spatiotemporal variations in lake status within the Hunza Basin that amplify downstream GLOF hazards. Climatic trends were assessed using CHELSA and TPMFD datasets. Our results show a substantial increase in glacial lake extent: the number of lakes rose from 97 in 1990 to 169 in 2021 (a 74.2

The Swat River Basin (SRB), a mountainous sub-catchment of the Indus Basin, has faced frequent floods in the past 25 years. Limited structural and non-structural measures, such as flood risk mapping, early warning systems, and land use planning, continue to expose the SRB. This study assessed and mapped riverine flood risk using the GIS-based Analytical Hierarchy Process (AHP) and simulated flood extent under current and future climate scenarios using hydrodynamic modelling. The GIS–AHP framework found that the most important factors for hazards and vulnerabilities were precipitation, elevation, and population density. The resulting flood risk map indicated that approximately 29% of the SRB falls within high-to-very-high risk zones, mainly concentrated in populated floodplains and agricultural lands. HEC-RAS 2D simulations projected that under a high-emission climate scenario of 21 st -Century, flood depths could reach up to ~31 m with velocities exceeding ~6 m/s, inundating ~26% of the Area of Interest (AOI), i.e., the high to very high risk zone in the Chakdara downstream part of SRB. The integrated methodology is novel in combining hazard, vulnerability, and hydrodynamic simulations and is transferable to other mountainous, snow- and glacier-fed basins, providing a robust tool for flood risk assessment and mitigation. These results show the significance of integrated strategies, climate-resilient planning, and better land use management to lower the flood risk and protect vulnerable communities.

The HKH Snow Update 2026 highlights a worrying decline in seasonal snow across the Hindu Kush Himalaya, with snow persistence dropping to 27.8% below normal—the lowest in over two decades and the fourth consecutive year of decline. Since snowmelt supplies about a quarter of the region’s river water—and even more in western basins—this reduction signals potential water shortages in the coming spring and summer, affecting agriculture, hydropower, and livelihoods for nearly two billion people. Most river basins are experiencing below-normal snow levels, increasing the risk of drought, groundwater stress, and reduced river flows. The report stresses the urgent need for better water management, early warning systems, and coordinated regional action to prepare for and mitigate the growing water crisis.

Glacier surges are ice flow instabilities characterized by periods of acceleration, during which mass is rapidly transferred from high to low elevations and the glacier front often advances. In this Review, we outline global trends in glacier surging and the influence of climate on the distribution and behaviour of surge-type glaciers and surge-related hazards. Glaciers exhibit diverse surging behaviours and typically recur at intervals that range from 5 years to over 100 years, with all surges largely driven by a reduction in basal friction. Most of the ~3,100 surge-type glaciers identified globally are clustered in the Arctic and Subarctic (48.3%) and High Mountain Asia (50.5%), where climate conditions are conducive to the development of surge instabilities, and there is emerging evidence that climate warming is changing surge behaviour. At least 81 surge-type glaciers globally have caused hazards such as ice-dammed glacial lake outburst floods, which can lead to infrastructure damage and loss of life. Future research should acquire spatiotemporally high-resolution remote-sensing data and direct observations of basal processes during all stages of surges, develop numerical models to better capture surge mechanisms and diversity, and project the impact of future climate warming on surge-type glacier behaviour and distribution. Glacier surges are rapid ice flow acceleration and mass transport events, which can threaten nearby communities, infrastructure and habitats. This Review discusses the global distribution, behaviour and associated hazards of glaciers that are prone to surging and how these are being affected by climate change.

Hydropower infrastructure in glacier-fed mountain regions is exposed to interacting hydrometeorological, geomorphic, cryospheric, and seismic hazards, yet plant-level evidence linking these hazards to documented infrastructure disruption remains limited. We compiled a field-verified, asset-level dataset for 46 hydropower stations in Baltistan, northern Pakistan, combining administrative repair or disruption records, inflation-adjusted repair expenditure, and GIS-derived relative hazard-conditioning indicators for 2010–2019 and 2024–2025. The archive contained 150 repair or disruption records, and 25 of the 46 stations experienced at least one recorded disruption event during 2010–2019. Flash floods were the most frequently assigned hazard category, followed by landslides, heavy snowfall, rockfall, earthquakes, and glacial lake outburst floods. Documented damage and repair expenditure were concentrated in power-generation units, headworks, transformers, and penstocks. Installed capacity increased from 17.18 MW in 2009 to 65.319 MW in 2025. Skardu contained more than half of the regional installed capacity despite having a lower relative hazard-conditioning score than Shigar, which recorded the largest raw disruption burden and the highest relative hazard-conditioning score. This mismatch shows that recent capacity expansion has increased the amount of infrastructure potentially exposed to mountain hazards, highlighting the need to integrate hazard screening into future investment and upgrading decisions.

The Hindu Kush Himalaya (HKH) hosts the largest concentration of glaciers, seasonal snow, and permafrost outside the polar regions. Ongoing climate change has accelerated glacier mass loss, reduced snow cover, degraded permafrost, and altered runoff seasonality. These changes have amplified multihazard risks such as glacial lake outburst floods, avalanches, and landslides, with cascading impacts on water, energy, food, ecosystems, and livelihoods. Yet, field monitoring remains sparse, fragmented, and uneven across the region with limited long-term records and minimal data sharing. This perspective presents a Regional Cryosphere Strategy (RCS) for the HKH that responds to these deficits by: (i) consolidating and institutionalising standardised monitoring of glaciers, snow, and permafrost; (ii) building sustained capacity through specialised regional capacity-building activities, fellowships, and shared instrumentation with priority given to a Gender Equality and Social Inclusion (GESI) framework; (iii) establishing a Regional HKH CryoHub to ensure Findable, Accessible, Interoperable, and Reusable (FAIR) and policy-relevant data and knowledge services; and (iv) prioritising operational decision-support services such as the HKH seasonal Snow Watch for water and energy planning, hazard monitoring and early warning systems, and basin-scale assessments that link cryosphere trends to risks for people and infrastructure. This strategy is designed to align HKH observations and services with global initiatives, ensuring that regional data streams inform global assessments while countries can access technical and financial support mechanisms. We argue that a basin-representative, quality-assured, and interoperable cryosphere observation and services system can strengthen regional resilience, reduce risks, and amplify the HKH voice in global climate dialogues.

The water regime in Pakistan’s northern region has experienced significant changes regarding hydrological extremes like floods because of climate change. Coupling hydrological models with remote sensing data can be valuable for flow simulation in data-scarce regions. This study focused on simulating the snow- and glacier-melt runoff using the snowmelt runoff model (SRM) in the Gilgit and Kachura River Basins of the upper Indus basin (UIB). The SRM was applied by coupling it with in situ and improved cloud-free MODIS snow and glacier composite satellite data (MOYDGL06) to simulate the flow under current and future climate scenarios. The SRM showed significant results: the Nash–Sutcliffe coefficient (NSE) for the calibration and validation period was between 0.93 and 0.97, and the difference in volume (between the simulated and observed flow) was in the range of −1.5 to 2.8% for both catchments. The flow tends to increase by 0.3–10.8% for both regions (with a higher increase in Gilgit) under mid- and late-21st-century climate scenarios. The Gilgit Basin’s higher hydrological sensitivity to climate change, compared to the Kachura Basin, stems from its lower mean elevation, seasonal snow dominance, and greater temperature-induced melt exposure. This study concludes that the simple temperature-based models, such as the SRM, coupled with improved satellite snow cover data, are reliable in simulating the current and future flows from the data-scarce mountainous catchments of Pakistan. The outcomes are valuable and can be used to anticipate and lessen any threat of flooding to the local community and the environment under the changing climate. This study may support flood assessment and mapping models in future flood risk reduction plans.

The snow and glacier-fed Swat River Basin (SRB), located in the Hindukush region of Pakistan, plays a vital role in supporting ecosystems and downstream communities. However, the basin is highly vulnerable to climate change, as evidenced by frequent historical floods. This study simulated historical and future snowmelt runoff using the Snowmelt Runoff Model (SRM), integrated with an enhanced MODIS snow and glacier product (MOYDGL06*), along with Digital Elevation Model (DEM) and hydro-meteorological data. The model was calibrated and validated over 2005-2009 and 2011-2015, respectively, using basin-wide and zone-wise simulation approach. The key findings of the study indicated: 1) SRM coupled with the improved snow product effectively simulated daily river discharge, achieving mean Nash-Sutcliffe Efficiency (NSE) values of 0.90-0.91 and Volume Differences (D-v) of 0.51% to -1.31% during calibration, and NSE of 0.84-0.87 with D-v of -0.83% to -2.27% during validation. The basin-wide approach performed more consistently due to integrated hydrological representation and lower parameter uncertainty. 2) Future projections under three RCP scenarios indicate increases of similar to 8-18% (2046-2065) and similar to 7-34% (2081-2100) in mean annual flow and increases of similar to 7-16% and similar to 7-30% in mean summer flow, respectively. An increase of 1 degrees C in temperature is projected to enhance both seasonal and annual flows by about 6-7%. These projected increases are primarily attributed to enhanced snow and glacier melt due to rising temperatures. The findings emphasize the need for adaptive strategies in water resources management and flood risk mitigation in the study area, especially under changing climatic conditions.

The presence of a Karakoram Anomaly (KA) where, in contrast to most global glaciers, regional glaciers are reported to have either stable or quasi-positive mass balance commonly has been challenged by recent glacier mass balance studies in response to decadal variability in temperature and precipitation. Here, we examine the amplitude and temporal evolution of the KA by observing hydroclimatic (temperature, precipitation, snow and streamflow) trends in the extensive snow/glacier-fed Hunza River Basin (HRB). We use daily time series of in situ hydroclimatic data in combination with (reanalysis/satellite) products (1995-2021), and MODIS Snow Covered Area (SCA) (2001-2020) to quantify the persistence of KA. The Wavelet Transfer Function (WTF), Innovative Trend Analysis (ITA), and Mann-Kendall (MK) tests validated the direction and extent of secular hydroclimatic trends. We further establish a hydroclimatic relationship for HRB using an Artificial Neural Networks (ANNs) incorporating more extensive variables of relative humidity and solar radiation for the model robustness. Transitioning of the KA to glacier mass loss is confirmed to be a result of climatic trends, and specifically summertime - focused enhanced intense warming, have triggered regional snow cover removal and increased streamflow. Mean annual near-surface temperatures in Khunjerab significantly increased by 0.33 and 0.26 ∘C/decade from (1995-2021) based on analyses of data from ERA5 and stations, respectively. The SCA trends are primarily negative in summer and positive in winter, corresponding to enhanced winter flows. The WTF and ITA indicate a significant decline in SC during January, April, May, August and October. Temperature exhibits a significant causal relationship with streamflow, snow and relative humidity. Granger's index and ANNs demonstrate that 2-m temperatures, snow cover, relative humidity, and solar radiation have stronger correlations to streamflow than precipitation.

Climate change is a global issue that significantly impacts various regions, including South Asia, which is particularly vulnerable to climate extremes. Extensive research is required to address the complex interplay between climate change and extreme weather events in South Asia (Bangladesh, Nepal and Pakistan). This study presents a case study of an Asia-Pacific Network for Global Change Research (APN) project focusing on climate change research, capacity buildingand science-to-policy communication on climate extremes in South Asia. Climate change research emphasises the importance of research to understand the changing patterns and impacts of climate extremes in the region. It underscores the need for robust scientific methodologies, data collectionand analysis to generate reliable evidence for policymakers and stakeholders. The capacity building efforts involve training programmes, workshopsand knowledge-sharing platforms, which are critical to enhancing the capabilities of local researchers, institutionsand communities in conducting climate change research and developing adaptation and mitigation strategies. The science communication includes disseminating the study’s findings to stakeholders, including policymakers, researchers, communities, mediaand civil society organisations. Overall, collaborative efforts between South Asian countries are important for climate change research, capacity buildingand science-to-policy communication to build resilience and mitigate the impacts of climate change.

The cryosphere in crisisThe global cryosphere is in crisis.Snow and ice on land and at sea are shrinking in response to rising air and ocean temperatures, posing new challenges to those who depend on them for survival.Last year saw record-low sea ice extent in Antarctica [1], and an increasing body of research now indicates that parts of the West Antarctic Ice Sheet are unstable even at present day temperatures [2].The Arctic is warming at nearly four times the global average rate [3], a rate so high that it is affecting the global average value, pushing us across the Paris agreement's 2C limit around eight years earlier [4].Melt driven runoff from Greenland has grown by 20% [5], with the ice sheet contributing more than 1.2 cm to global sea level rise in that time [6].Based on our emissions to date, we appear to have already committed to a further 25 cm [7].Away from the polar regions, millions of people worldwide are now at risk from the changing cryosphere.Glaciers in High Mountain Asia faced an accelerated melting by 65% in recent years compared to the first decade of this century [8].Similarly, snow cover days declined at a rate of five snow cover days per decade since 1950 [9].Both the components comprise between 5% and 80% contribution to runoff, increasing from east to west in the region critical for ~1.9 billion people-a quarter of the world's population [10].In Norway, where about 94% of the electricity generation is based on hydropower of which 15% from glaciated catchment areas, the majority of major glaciers will have disappeared by 2100 [11].These rapid cryosphere changes are expected to cause more frequent and intense glacial lake outburst floods, water scarcity, increased landslide risks, and disruptions of communities.

The recent retreat of glaciers in High Mountain Asia is a major issue for downstream communities. Similarly, glaciers in the Astore Basin are melting, causing glacial lakes to expand faster, new lakes to form, and increasing the risk of glacial lakes outburst floods (GLOFs). The present study uses Landsat data from 1993 to 2021 to explore seasonal and decadal changes in glacier lakes, which are validated using an in situ differential Global Positioning System (dGPS). During the ablation period (June - October) of 2021, we observed a five-fold increase (18 to 100) in the number of glacier lakes, as well as a six-fold increase (0.62 to 3.86 km2) in lakes larger than 0.01 km2. Over the last decade, from 2011 to 2020, the number of potentially dangerous glacial lakes (PDGLs) has doubled. GLOF risk must be reduced through continual monitoring of these lakes. Prioritizing the deployment of GLOF monitoring and early warning systems, as well as sustainable water management practices, is critical for mitigation and adaptation measures in mountainous regions.

The global cryosphere is experiencing accelerated melting due to climate change. Currently, the Karakoram anomaly is under discussion with a debate about the possibility that the anomaly may have recently ended. This study aims to evaluate the up-to-date changes in snow cover in the western Karakoram region. We observed the snow cover changes in Passu and Ghulkin valleys in the Hunza River basin (HRB) of the Karakoram through multi-temporal Landsat satellite data between 1995 and 2022. We found a significant reduction in snow cover in these valleys, with an average reduction rate of 0.42 km2/yr, resulting in a total reduction of ∼11.46 km2 between 1995 and 2022. This reduction in snow cover is consistent with the mass loss of glaciers in the Karakoram region in recent years. The decline in snow cover in these valleys is also consistent with the meteorological data. The temperature in summer (June) has significantly increased whereas the precipitation in the accumulation season (March) has decreased. These rapid changes suggest that it is crucially important to monitor the snow cover on a regular basis to support downstream management of snowmelt runoff. In addition, there is a need of planning for mitigation and adaptation strategies for snow-related hazards.

Glacier surges can create ice-dammed lakes when the advancing terminus blocks drainage. Such lakes are inherently unstable and can drain abruptly as glacial lake outburst floods (GLOFs), presenting a hazard to downstream populations and infrastructure in high mountain environments. We present satellite image analysis of the evolution of an ice-dammed lake formed by the 2018-20 surge of Shisper Glacier, western Karakoram. Our analysis identifies six phases of lake evolution. A large lake of up to 33.7 +/- 9% million m3 formed in 2018-19, 2019-20, 2020-21 and 2021-22. In each case, the lake began to fill late in the year, reached a maximum size in May, and had completely drained between May and July, typically over 1-2 days. This analysis provides further evidence that GLOF hazards associated with lakes dammed by glacier surges can persist for several years after surge termination.

Abstract Many efforts have been made by the scientific community to produce gridded datasets with high spatial resolution because they are essential for climate change assessment, impact studies, decision‐making, etc. This study fits into this context and describes the methods used to prepare a 5‐km gridded product of precipitation and minimum and maximum temperatures by merging observed data from meteorological stations, from 1981 to 2016, of Bangladesh, Nepal, and Pakistan with ERA5 reanalysis. The step‐by‐step methods for station data quality control and the development of the 5‐km gridded data are presented. Additionally, we use the 5‐km dataset to show the main climate features of the three countries, which facilitate comparison with other data sources in the literature.

In August 2022, one of the most severe floods in the history of Pakistan was triggered due to the exceptionally high monsoon rainfall. It has affected ~ 33 million people across the country. The agricultural losses in the most productive Indus plains aggravated the risk of food insecurity in the country. As part of the loss and damage (L&D) assessment methodologies, we developed an approach for evaluating crop-specific post-disaster production losses based on multi-sensor satellite data. An integrated assessment was performed using various indicators derived from pre- and post-flood images of Sentinel-1 (flood extent mapping), Sentinel-2 (crop cover), and GPM (rainfall intensity measurements) to evaluate crop-specific losses. The results showed that 2.5 million ha (18% of Sindh's total area) was inundated out of which 1.1 million ha was cropland. The remainder of crop damage came from the extreme rainfall downpour, flash floods and management deficiencies. Thus approximately 57% (2.8 million ha) of the cropland was affected out of the 4.9 million ha of agricultural area in Sindh. The analysis indicated expected production losses of 88% (3.1 million bales), 80% (1.8 million tons), and 61% (10.5 million tons) for cotton, rice, and sugarcane. This assessment provided useful tools to evaluate the L&D of agricultural production and to develop evidence-based policies enabling post-flood recovery, rehabilitation of people and restoration of livelihood.

EDITORIAL article Front. Remote Sens., 10 May 2023Sec. Image Analysis and Classification Volume 4 - 2023 | https://doi.org/10.3389/frsen.2023.1204667

The catastrophic floods that hit Pakistan in summer 2022 represent the latest example of climate change-induced extreme events occurring in South Asia. In addition to the dramatic impact on population and infrastructures, this event threatened UNESCO World Heritage Sites (WHS) and properties of national interest. However, while a wealth of national and international mapping initiatives were conducted based on satellite imagery to assess damage to people, buildings and economic goods, the impact caused to archaeological sites and monuments has not been fully unveiled yet. To bridge this gap and provide an integrated approach that can be used by local end-users to assess damage and, in turn, collect evidence to inform and improve risk management plans, the present paper integrates Sentinel-1 and 2 imagery and mapping products derived from them (e.g., Copernicus Emergency Management Service Global Flood Mapping) with ground-truthing and geospatial datasets. Through a multidisciplinary collaboration between geologists, archaeologists, remote sensing and satellite image analysts, the integration methodology was tested on UNESCO and other heritage sites of national relevance located in the two mostly affected regions of Khyber Pakhtunkhwa and Sindh that were intentionally selected to represent different typologies of cultural heritage and governance in Pakistan. Finally, the information extracted from the present analysis was assessed in relation to the current national and international legislations, the official state of conservation reports and the activities conducted at each site to protect them against flood events. Given the accessibility to ready-to-use Copernicus products and that the present analysis can be replicated over time and other sites, the proposed methodology provides a feasible means to exploit satellite data in post-disaster mapping situations and contribute to the decision-making process for risk management.

Glaciers are generally believed to be subjugating by global warming but the Karakoram glaciers are reportedly maintaining their balance. Earlier studies in the Karakoram and its sub-basins have mostly addressed a short span of time and used complex models to understand the phenomenon. Thus, this study is based on a long-term trend analysis of the computed runoff components using satellite data with continuous spatial and temporal coverage incorporated into a simple degree day Snowmelt Runoff Model (SRM). The trends of melt runoff components can help us understanding the future scenarios of the glaciers in the study area. The SRM was calibrated against the recorded river flows in the Hunza River Basin (HRB). Our simulations showed that runoff contribution from rain, snow, and glaciers are 14.4%, 34.2%, and 51.4%, respectively during 1995–2010. The melting during the summer has slightly increased, suggesting overall but modest glacier mass loss which consistent with a few recent studies. The annual stream flows showed a rising trend during the 1995–2010 period, while, rainfall and temperatures showed contrasting increasing/decreasing behavior in the July, August, and September months during the same period. The average decreasing temperatures (0.08 °C per annum) in July, August, and September makes it challenging and unclear to explain the reason for this rising trend of runoff but a rise in precipitation in the same months affirms the rise in basin flows. At times, the warmer rainwater over the snow and glacier surfaces also contributed to excessive melting. Moreover, the uncertainties in the recorded hydrological, meteorological, and remote sensing data due to low temporal and spatial resolution also portrayed contrasting results. Gradual climate change in the HRB can affect river flows in the near future, requiring effective water resource management to mitigate any adverse impacts. This study shows that assessment of long-term runoff components can be a good alternative to detect changes in melting glaciers with minimal field observations.