Impact statement
Glaciers in High Mountain Asia support water supplies for human society and dryland ecosystems across vast inland regions. Global warming has resulted in severe glacier shrinkage in this “Asian Water Tower,” while the effects do not stop within the high mountain regions. Changes in the amount and timing of glacial meltwater will cascade downstream, affecting river flow and flood risk, soil moisture, groundwater levels, wetland condition, the availability of groundwater to support forest growth and survival, and ultimately the carbon storage capacity of midstream ecosystems. These ecological changes will, in turn, affect the stability of water supplies for downstream dryland cities. Therefore, we emphasize that glacier change should be managed as a basin-wide water security issue, not only as a cryospheric problem or a contribution to sea level rise. Practical action must begin with catchment-level vulnerability assessments and basin-specific projections of future runoff, flood peaks, groundwater recharge and ecosystem water demand. These assessments will guide when reservoir rules, dam releases, infrastructure standards and water allocation plans need to be updated. Investments should prioritize glacier and glacial lake monitoring, early warning systems, groundwater safeguards, efficient irrigation, water user associations and the protection and restoration of wetlands, forests and recharge zones. Engineering proposals near glaciers should be tested against conservation law, local environmental risks and possible downstream impacts. In transboundary basins, open data sharing and cooperation between upstream and downstream regions are essential. By linking glacier protection, ecosystem management and urban water planning, basin-wide coordination among countries, sectors and water users can reduce disaster risk, protect carbon sinks and help dryland cities manage near-term hydrological hazards while preparing for greater variability and long-term declines in glacier runoff.
Main
Water plays a fundamental role in food security, economic stability, hydropower production, public health and sanitation for human society. Demand for sustainable water supplies is growing across drylands in the Indus, Ganges, Brahmaputra, Aral, Balkhash, Tarim and Issyk-Kul River basins, whose headwaters originate in High Mountain Asia (Pritchard, Reference Pritchard2019; Figure 1). These glacier-fed systems support approximately 250 million people across multiple countries and connect glaciers, surface water, groundwater, ecosystems, rural landscapes and downstream cities. Given this complexity, we adopt a basin-wide approach that traces the ecological and hydrological cascade from glacier source regions to midstream ecosystems and downstream dryland cities while recognizing differences in the institutional and legal contexts of individual basins.
The Asian Water Tower and major glacier-fed river basins in High Mountain Asia. Glacier outlines were obtained from the Randolph Glacier Inventory version 7.0 (RGI 7.0 Consortium, 2023), major river basin boundaries from the GRDC Major River Basins dataset (GRDC, 2020) and river networks from HydroRIVERS (Lehner and Grill, Reference Lehner and Grill2013). The Tibetan Plateau Interior was delineated using HydroBASINS Level 4 data (Lehner and Grill, Reference Lehner and Grill2013). Country boundaries and lake data were obtained from Natural Earth.
Figure 1. Long description
The map uses a coordinate system from 55 degrees East to 105 degrees East and 20 degrees North to 55 degrees North. At the center is the Asian Water Tower, a high-altitude region densely populated with green-shaded glaciers. Radiating from this core are several colored river basins with blue river networks.
* Northwest: The Amu Darya and Syr Darya Basins in purple, covering parts of Uzbekistan, Kyrgyzstan, and Tajikistan.
* North: The Balkhash Basin in orange and the Tarim Basin in light blue.
* Northeast: The Yellow River Basin in light orange.
* East: The Yangtze Basin in light purple.
* Southeast: The Salween and Mekong Basins in light green.
* South: The Brahmaputra Basin in light blue, the Ganges Basin in light orange.
* Southwest: The Indus Basin in light green. The countries labeled in the southern part of the map include Nepal, Bhutan, Bangladesh, and India.
* Center-South: The Tibetan Plateau Interior in light yellow.
A legend in the bottom-left corner identifies green areas as Glaciers, light blue outlines as Lakes, and dark blue lines as Major rivers. A scale bar indicates 0 to 1000 kilometers. A North arrow is located in the top-right corner.
A consistent supply of glacier meltwater from high-altitude regions of High Mountain Asia is crucial for sustaining downstream dryland city development, including hydroeconomic activities, drought mitigation and demographic growth (Gu et al., Reference Gu, Schumacher, Wang, Yin and Fischer2025). In Nepal, the government diverts water from the Melamchi River to the Kathmandu Valley to augment the capital region’s water supply (Khadka and Khanal Reference Khadka and Khanal2008). Northern Indian cities, including Delhi, depend extensively on glacier-fed rivers like the Bhagirathi and Yamuna, which together meet much of the city’s water demand (Ghosh et al., Reference Ghosh, Kansal and Venkatesh2019). In Pakistan, the Soan River delivers glacially sourced water to Islamabad through the Simly Dam, while seepage from the Indus Basin Irrigation System sustains communities in southern Punjab (Jehangir et al., Reference Jehangir, Mudasser, Mahmood-ul-Hassan and Ali1998). The sustainability of these regions is deeply intertwined with the fate of High Mountain Asia, a region widely referred to as the “Asian Water Tower” (Immerzeel et al., Reference Immerzeel, Lutz, Andrade, Bahl, Biemans, Bolch, Hyde, Brumby, Davies, Elmore, Emmer, Feng, Fernández, Haritashya, Kargel, Koppes, Kraaijenbrink, Kulkarni, Mayewski, Nepal, Pacheco, Painter, Pellicciotti, Rajaram, Rupper, Sinisalo, Shrestha, Viviroli, Wada, Xiao, Yao and Baillie2020; Figure 1).
Amid rising global temperatures, the melting of High Mountain Asia’s glaciers represents one of the earliest affecting human societies. This region is warming at twice the global average rate (0.44 °C per decade versus 0.19°C per decade during 1979–2020) (Yao et al., Reference Yao, Bolch, Chen, Gao, Immerzeel, Piao, Su, Thompson, Wada, Wang, Wang, Wu, Xu, Yang, Zhang and Zhao2022), resulting in rapid cryospheric change and significant hydrological shifts in mountain river basins. Regional glacier losses are projected to intensify throughout the remainder of this century and beyond, potentially leading to the disappearance of roughly half of the current ice volume in High Mountain Asia. This declining ice reservoir will initially increase glacier discharge, reaching “peak water,” which is the point at which glacier meltwater runoff reaches its maximum before declining as glaciers continue to shrink, around 2030 under the IPCC’s RCP2.6 scenario, or about one to three decades later under RCP8.5. Projected peak annual runoff is expected to exceed the 1980–2000 average by 15% (Brahmaputra, RCP2.6) to 67% (Tarim, RCP8.5) (Huss and Hock, Reference Huss and Hock2018). However, subsequent reductions in glacier area and volume will cause substantial declines in runoff later this century.
The effects of glacial ablation on downstream sustainability therefore vary over time. In the short term, increased glacier runoff may enhance water availability for dryland cities. The augmented water supply from glacial ablation often stimulates socioeconomic development, which in turn increases water demand – a positive feedback loop that can accelerate the arrival of “peak water” and push the system toward unsustainability. Specifically, increased water availability may stimulate urban growth, industrial development and migration, locking cities into levels of demand that become unsustainable after “peak water.” Population growth should therefore not be regarded as an unlimited or inevitable consequence of temporarily elevated runoff. Instead, population and land use planning must be aligned with projected long-term water availability through controls on water-intensive development, compact urban growth, leakage reduction, water reuse and demand management (He et al., Reference He, Liu, Wu, Pan, Fang, Li and Bryan2021; Savelli et al., Reference Savelli, Mazzoleni, Di Baldassarre, Cloke and Rusca2023).
Additionally, this temporary surge elevates the risk of hydrological hazards, including riverine flooding. Glacier ablation has prompted the formation and expansion of proglacial lakes, increasing the risks of glacial lake outburst floods (GLOFs). In southeastern Tibet, villages and electrical infrastructure were twice destroyed within a decade – in 2013 and 2020 – by breaches of moraine-dammed lakes (Peng et al., Reference Peng, Wang, Zhang, Veh, Sattar, Chen and Allen2023). Even minor GLOFs can isolate communities for years, as reconstructing transport and communication networks in remote high mountain regions is difficult, expensive, time-consuming and carries a high risk of failure. Future deglaciation is expected to increase the risk of GLOFs in parts of High Mountain Asia, reinforcing the need for lake monitoring, early warning systems and risk-informed infrastructure planning (Zheng et al., Reference Zheng, Allen, Bao, Ballesteros-Cánovas, Huss, Zhang, Li, Yuan, Jiang, Yu, Chen, Stoffel and Bolch2021; Taylor et al., Reference Taylor, Robinson, Dunning, Carr and Westoby2023).
These growing demands will coincide with increasing pressure on downstream water infrastructure. Irrigation systems, reservoirs and flood control facilities were designed using historical records of rainfall, snowfall, ice thickness, runoff timing and peak discharge hydrographs (Dickson et al., Reference Dickson, Danilenko and Jacobsen2010). As glacier retreat changes the magnitude, timing and variability of river flow, these historical baselines may no longer support reliable storage, allocation and flood protection. Management agencies will therefore need to upgrade design standards, reservoir rule curves and water release rules, water allocation rights/licences and procedures, and emergency protocols using updated observations and basin-specific projections.
The long-term consequences of continued glacier shrinkage are severe. It is projected that by 2100, glacier volume in High Mountain Asia could decrease by at least 30%, severely jeopardizing water security for dryland cities (Huss and Hock, Reference Huss and Hock2018). Glacial-related hazards, such as GLOFs and ice–rock avalanches, have the potential to cause extensive destruction to downstream communities and infrastructure, at times even trigger transboundary geopolitical tensions (Veh et al., Reference Veh, Wang, Zirzow, Schmidt, Lützow, Steppat, Zhang, Vogel, Geertsema, Clague and Korup2025). Addressing these interconnected challenges necessitates the implementation of integrated basin management strategies that explicitly account for diminishing glacier contributions as a core element of sustainable water resource management. Such approaches are essential to maintain hydrological stability, reduce risks and safeguard regional socioeconomic resilience in the context of ongoing climate change and glacial retreat.
Integrated basin management with upstream, midstream, and downstream linkages
To enhance the sustainability of water resources in High Mountain Asia that rely on glacier meltwater, we propose a basin-wide integrated approach, embedded within the broader framework of integrated water resource management (Stringer et al., Reference Stringer, Mirzabaev, Benjaminsen, Harris, Jafari, Lissner, Stevens and Der Pahlen2021). This approach involves preserving ice reserves in the upper reaches, applying nature-based solutions to strengthen carbon sequestration and water retention in the middle reaches and optimizing water usage in downstream dryland cities (Figure 2). Such a comprehensive strategy directly tackles the effects of climate change-induced glacier ablation from source to sink while also addressing the socioeconomic challenges related to equitable water allocation. Because several glacier-fed basins originating in High Mountain Asia cross national boundaries, effective implementation must coordinate planning among upstream, midstream and downstream countries. Priorities should include joint monitoring, hydrological data and early warning information sharing, and coordination of water allocation, reservoir operations, infrastructure planning, and climate adaptation and mitigation strategies across entire basins.
Integrated basin-wide approach across the upper, middle and lower reaches, as well as within city centers. The framework synthesizes measures involving artificial reservoirs (Farinotti et al., Reference Farinotti, Round, Huss, Compagno and Zekollari2019), ice stupas (Nüsser et al., Reference Nüsser, Dame, Kraus, Baghel and Schmidt2019), glacier covers (Moore et al., Reference Moore, Gladstone, Zwinger and Wolovick2018; Cao et al., Reference Cao, Chi, Zhu, Pang, Ke, Zhang, Chen and Zhu2025), wetland and peatland restoration (Acreman and Holden, Reference Acreman and Holden2013; Mitsch et al., Reference Mitsch, Bernal, Nahlik, Mander, Zhang, Anderson, Jørgensen and Brix2013), ecosystem restoration (Farley et al., Reference Farley, Jobbágy and Jackson2005; Jackson et al., Reference Jackson, Jobbágy, Avissar, Roy, Barrett, Cook, Farley, le Maitre, McCarl and Murray2005; Feng et al., Reference Feng, Fu, Piao, Wang, Ciais, Zeng, Lü, Zeng, Li, Jiang and Wu2016; Ellison et al., Reference Ellison, Morris, Locatelli, Sheil, Cohen, Murdiyarso, Gutierrez, van Noordwijk, Creed, Pokorny, Gaveau, Spracklen, Bargués Tobella, Ilstedt, Teuling, Gebrehiwot, Sands, Muys, Verbist, Springgay, Sugandi and Sullivan2017), water-efficient irrigation (Howell, Reference Howell2001; Perry et al., Reference Perry, Steduto, Allen and Burt2009) and qanat systems (English, Reference English1968; Beaumont, Reference Beaumont1971), within an integrated water resource management framework (Stringer et al., Reference Stringer, Mirzabaev, Benjaminsen, Harris, Jafari, Lissner, Stevens and Der Pahlen2021).
Figure 2. Long description
A central landscape illustration depicts a mountain range transitioning through several ecological zones. At the highest elevation is a snow-covered peak with a glacier. A line points to geotextiles and advanced materials used to cover the glacier. Below the glacier are subnival scree slopes, followed by alpine desert, ice terraces, and subalpine desert.
A river flows down from the glacier, with ice stupas and hydropower infrastructure shown along its course. The surrounding land includes permafrost, peatlands restoration, and montane desert. Further down, the landscape transitions into cultivated areas, an oasis, and a city center.
Three circular callouts provide technical details.
1. Top-left: A diagram of an ice stupa showing how glacier meltwater hitting winter air forms a cone of ice crystals.
2. Top-right: A photo of a reservoir and dam labeled construction and strategic operation of artificial reservoirs.
3. Middle-left: A cross-section of a qanat system showing a mother well, access shafts, and a qanat channel above the water table and bedrock.
Solar panels and wind farms are shown in the main landscape and are labeled solar energy and wind farms. Additional labels in the lower basin include afforestation and reforestation, micro-irrigation, drip systems, and water-efficient practices, and ecosystem restoration by preventing overgrazing in livestock-grazing areas.
Upstream: Preserving ice reserves and mitigating glacier ablation
A critical upstream management measure involves the construction and strategic operation of artificial reservoirs downstream of glacier termini. These reservoirs can store surplus glacier meltwater during wet seasons and provide a stable water supply during dry periods when river runoff declines significantly (Farinotti et al., Reference Farinotti, Round, Huss, Compagno and Zekollari2019). This enhanced regulation capacity helps ensure that – despite variability in glacier ablation patterns – both human communities and ecosystems retain access to essential water resources across seasonal cycles. However, such reservoirs may also increase downstream exposure to catastrophic flood hazards in tectonically active glacierized valleys where ice–rock avalanches, GLOFs, debris flows and sediment pulses can damage hydropower and water storage infrastructure (Veh et al., Reference Veh, Korup and Walz2020; Shugar et al., Reference Shugar, Jacquemart, Shean, Bhushan, Upadhyay, Sattar, Schwanghart, McBride, Van Wyk, Mergili, Emmer, Deschamps-Berger, McDonnell, Bhambri, Allen, Berthier, Carrivick, Clague, Dokukin, Dunning, Frey, Gascoin, Haritashya, Huggel, Kääb, Kargel, Kavanaugh, Lacroix, Petley, Rupper, Azam, Cook, Dimri, Eriksson, Farinotti, Fiddes, Gnyawali, Harrison, Jha, Koppes, Kumar, Leinss, Majeed, Mal, Muhuri, Noetzli, Paul, Rashid, Sain, Steiner, Ugalde, Watson and Westoby2021). For instance, an ice–rock avalanche struck Chamoli, India in 2021 and generated a destructive downstream cascade affecting hydropower facilities, bridges and settlements (Shugar et al., Reference Shugar, Jacquemart, Shean, Bhushan, Upadhyay, Sattar, Schwanghart, McBride, Van Wyk, Mergili, Emmer, Deschamps-Berger, McDonnell, Bhambri, Allen, Berthier, Carrivick, Clague, Dokukin, Dunning, Frey, Gascoin, Haritashya, Huggel, Kääb, Kargel, Kavanaugh, Lacroix, Petley, Rupper, Azam, Cook, Dimri, Eriksson, Farinotti, Fiddes, Gnyawali, Harrison, Jha, Koppes, Kumar, Leinss, Majeed, Mal, Muhuri, Noetzli, Paul, Rashid, Sain, Steiner, Ugalde, Watson and Westoby2021). Future infrastructure should therefore be preceded by multihazard assessments that consider glacier retreat, unstable slopes, extreme runoff and possible cascading processes into practical amelioration measures. Reservoir operations should be updated adaptively as hydrological observations, climate projections and post-event assessments improve our understanding of inflow variability and flood risks (Fletcher et al., Reference Fletcher, Lickley and Strzepek2019). Periodic sedimentation surveys, which assess sediment accumulation and the resulting loss of storage capacity, together with suspended sediment monitoring are also needed to maintain the capacity to regulate variable flows (Kondolf et al., Reference Kondolf, Gao, Annandale, Morris, Jiang, Zhang, Cao, Carling, Fu, Guo, Hotchkiss, Peteuil, Sumi, Wang, Wang, Wei, Wu, Wu and Yang2014).
Additionally, in regions like Ladakh, ice stupas store winter stream water by diverting it downhill through gravity-fed plastic pipes and spraying it into cold air, where it freezes into cone-shaped ice towers. These ice towers melt gradually in warmer periods, releasing the seasonally stored meltwater (Nüsser et al., Reference Nüsser, Dame, Kraus, Baghel and Schmidt2019).
Alongside storing and regulating meltwater, efforts to decelerate glacier retreat are also emerging, though still implemented sporadically. In Austria, geotextiles covers have been tested as localized measures to reduce surface ablation by reflecting shortwave radiation (Moore et al., Reference Moore, Gladstone, Zwinger and Wolovick2018). In China, artificial snowfall is used to increase surface albedo, curbing ice loss and replenishing glacier mass (Wang et al., Reference Wang, Yue, Wang, Li, Du, Ming and Li2020). Advanced materials, such as nanotextiles, demonstrate superior potential for mitigating glacier ablation by reflecting solar radiation more efficiently (Cao et al., Reference Cao, Chi, Zhu, Pang, Ke, Zhang, Chen and Zhu2025). These materials can reduce glacier ablation by up to 56% and possess a higher albedo compared to conventional geotextiles. Artificial snow seeding has been tested in regions like the Qilian Mountains to boost snowfall and glacial mass accumulation. However, its effectiveness, environmental impacts, costs, scalability and long-term sustainability remain uncertain because it strongly depends on suitable atmospheric and cloud conditions (Rauber et al., Reference Rauber, Geerts, Xue, French, Friedrich, Rasmussen, Tessendorf, Blestrud, Kunkel and Parkinson2019). It must therefore be regarded as a localized intervention rather than a substitute for greenhouse gas mitigation or long-term adaptation.
The feasibility of these upstream interventions also depends on the relevant policy and legal contexts. Their implementation requires compliance with national and regional conservation laws, environmental impact assessment requirements, land use controls and community consultation. In the Xizang Autonomous Region, the Regulations on Glacier Protection came into effect on October 1, 2024. The regulations require glacier protection planning and stricter review of development projects and prohibit projects that alter the original condition of glaciers (Xizang Autonomous Region, 2024). Source region interventions should therefore be assessed case by case and pursued only where they are legally permissible, technically justified, environmentally acceptable and supported by long-term monitoring. In highly protected or ecologically sensitive areas, avoiding disturbance and reducing greenhouse gas and black carbon emissions may be more appropriate than direct engineering intervention (Mani, Reference Mani2021).
Midstream: Enhancing carbon sinks and water retention
Midstream wetlands, riparian forests, peatlands and groundwater recharge zones form important buffers between glacier change and downstream water security. Changes in the volume and timing of meltwater can alter soil moisture, groundwater levels and wetland hydroperiods, potentially resulting in insufficient groundwater to support forest growth and survival, thereby affecting vegetation productivity, decomposition and carbon storage. When these ecosystems dry or degrade, reduced infiltration and water retention increase sediment delivery, weaken dry season flow regulation and promote the release of stored carbon (Johnston, Reference Johnston1991; Acreman and Holden, Reference Acreman and Holden2013; Loisel and Gallego-Sala, Reference Loisel and Gallego-Sala2022). These processes create ecohydrological feedbacks linking glacier change, ecosystem condition, carbon storage and regional water security (Mitsch et al., Reference Mitsch, Bernal, Nahlik, Mander, Zhang, Anderson, Jørgensen and Brix2013; Li et al., Reference Li, Fu, Wang, Stringer, Wang, Li, Liu and Zhou2021; Yao et al., Reference Yao, Bolch, Chen, Gao, Immerzeel, Piao, Su, Thompson, Wada, Wang, Wang, Wu, Xu, Yang, Zhang and Zhao2022). Because continued warming will intensify glacier loss, these ecosystem-based measures cannot replace greenhouse gas mitigation, but they can complement it by protecting carbon stores and reducing water-related vulnerability within the basin.
Midstream restoration should be guided by water balance rather than vegetation expansion alone. Wetlands and peatlands should be protected when their seasonal water regimes support soil moisture, groundwater recharge and long-term carbon storage (Mitsch et al., Reference Mitsch, Bernal, Nahlik, Mander, Zhang, Anderson, Jørgensen and Brix2013). In adjacent riparian and recharge areas, management should avoid land conversion and maintain hydrological connectivity. In forests and shrublands, restoration should focus on improving infiltration and reducing erosion, especially on unstable slopes. Locally adapted measures, including terracing, small check dams, grassland recovery and riparian revegetation, are preferable to uniform increases in tree cover. In water-limited basins, afforestation should be applied selectively because dense or poorly matched plantations may reduce streamflow and soil water storage through higher evapotranspiration (Farley et al., Reference Farley, Jobbágy and Jackson2005; Jackson et al., Reference Jackson, Jobbágy, Avissar, Roy, Barrett, Cook, Farley, le Maitre, McCarl and Murray2005). Restoration should favor native drought-tolerant species and mixed vegetation where water availability is limited, and its effects should be assessed against downstream water use since reservoir operation, irrigation demand and urban expansion may offset hydrological gains from ecosystem restoration (Feng et al., Reference Feng, Fu, Piao, Wang, Ciais, Zeng, Lü, Zeng, Li, Jiang and Wu2016; Ellison et al., Reference Ellison, Morris, Locatelli, Sheil, Cohen, Murdiyarso, Gutierrez, van Noordwijk, Creed, Pokorny, Gaveau, Spracklen, Bargués Tobella, Ilstedt, Teuling, Gebrehiwot, Sands, Muys, Verbist, Springgay, Sugandi and Sullivan2017).
Downstream: Water resource management strategies
Downstream dryland cities are the end recipients of ecological and hydrological cascades. By the time linked effects caused by upstream and midstream reach urban and agricultural water systems, downstream areas may face greater pressure on drinking water supply, irrigation, hydropower, flood control, sanitation and ecosystem maintenance, especially as glacier runoff becomes more variable and eventually declines after “peak water.” Downstream management therefore must connect urban water planning, rural land management, aquifer protection and infrastructure operation within the same basin framework.
Water availability in the lower basin is shaped not only by upstream flow but also by the way farms, villages and cities handle water once it arrives. In rural landscapes, the immediate priority is to capture and retain water in the soil and facilitate its infiltration into shallow groundwater system. Measures that conserve soil and water, maintain or improve soil condition and health, and enhance infiltration, such as slope stabilization, riparian protection, wetland conservation and recharge zone protection, can help sustain dry season baseflow. This is especially important in Central Asian drylands, where agriculture often accounts for nearly 90% of total water withdrawals and surface irrigation remains widespread (Frenken, Reference Frenken2013). Improving irrigation efficiency is therefore essential, but it should not be treated as a purely technical fix. Microirrigation, drip systems, canal lining, leakage control and better irrigation scheduling will reduce avoidable losses, although basin-scale benefits depend on how return flows and irrigated area are managed (Howell, Reference Howell2001; Perry et al., Reference Perry, Steduto, Allen and Burt2009). Urban expansion adds another constraint: impervious surfaces and rising municipal demand can quickly offset gains from rural restoration. Downstream planning therefore needs to retain floodplains and recharge areas, improve stormwater storage, reuse treated wastewater where feasible and involve water user associations in daily allocation and maintenance decisions, especially where farmers, smallholders, pastoral communities, women and groundwater users are poorly represented (Wang and Wu, Reference Wang and Wu2018).
Downstream adaptation also requires low-energy ways to store and convey water across dryland landscapes. Qanats, an ancient water management technology, can be adapted to capture, store and distribute valuable glacier meltwater. These systems can be strategically constructed in piedmont areas and alluvial fans located far below glaciers. Their underground channels intercept meltwater as it percolates into groundwater systems, similar to traditional qanats that tap into snowmelt-recharged aquifers. The core mechanism consists of gently sloping underground tunnels that use gravity to transport glacier-sourced water from high elevations to water-scarce lowlands, requiring little or no pumping energy input and reducing evaporation losses compared with open canals (English, Reference English1968; Beaumont, Reference Beaumont1971). Their value, however, depends on local hydrogeology. A qanat is unlikely to work where the water table is too deep, recharge is weak or highly seasonal, or sediments do not allow reliable groundwater movement without excessive leakage. It can also create new conflicts if it redirects water away from springs, shallow wells, wetlands or existing irrigation users. For this reason, construction or rehabilitation should begin with a careful water balance and rights assessment, followed by monitoring and limits on abstraction where needed. Where some users gain water at the expense of others, legally binding safeguards should be designed, developed and implemented to protect recharge areas. As a last resort, compensation or alternative water access should be provided to affected groundwater users and smallholders, while measures should also be taken to protect groundwater-dependent ecosystems and high-value farmlands.
Reliable and timely monitoring, together with open information sharing, can strengthen the implementation of these downstream measures. Advancements in artificial intelligence (AI) and big data potentially offer further opportunities to enhance water management (Richards et al., Reference Richards, Tzachor, Avin and Fenner2023). AI-driven models have been applied to groundwater potential mapping and hydrological forecasting, including rainfall runoff, streamflow and flood prediction (Mosavi et al., Reference Mosavi, Ozturk and Chau2018; Thanh et al., Reference Thanh, Thunyawatcharakul, Ngu and Chotpantarat2022). However, their outputs may support water allocation decisions and efforts to reduce water losses but do not ensure these outcomes, as their performance depends on data quality, model validation and appropriate treatment of uncertainty (Richards et al., Reference Richards, Tzachor, Avin and Fenner2023). These tools should complement, rather than replace, local monitoring and stakeholder participation. Their results need to be communicated clearly to management agencies, water user associations and affected communities. Concurrently, clean energy initiatives—such as installing solar panels, promoting energy-efficient appliances and incorporating natural ventilation in building design—can reduce greenhouse gas emissions, indirectly protecting glaciers by mitigating climate change. Dryland cities in High Mountain Asia possess abundant yet underutilized renewable energy resources. For instance, Xinjiang and Qinghai hold significant solar energy potential, with Xinjiang alone accounting for 18.92% of China’s exploitable solar energy. However, their installed solar capacity remains relatively low. Clean energy investment can reduce the energy burden of water supply while helping dryland cities adapt to more variable glacier-fed runoff.
Challenges and future perspectives
Although integrated basin management can help dryland cities respond to glacier ablation, implementation will be challenging. Most measures involve trade-offs rather than simple gains. A reservoir, water harvesting project or restoration program may reduce local risk, but it can also alter downstream flows, groundwater storage or ecosystem water needs (Damania et al., Reference Damania, Desbureaux, Hyland, Islam, Moore, Rodella, Russ and Zaveri2017). And its implementation faces significant technical and financial obstacles. For example, covering glaciers with advanced materials shows great promise but is constrained by high costs and technological limitations. Similarly, large-scale basin management requires substantial financial investment, posing a challenge for less-developed dryland cities within High Mountain Asia. Addressing these issues will require exploring innovative financing mechanisms, such as international climate funds, public–private partnerships and community-led cooperative investments.
This article identifies basin-scale adaptation needs under glacier retreat, but the design of detailed governance and safeguard mechanisms remains beyond its scope.
Future research should therefore translate these findings into basin-specific adaptation frameworks that integrate three components: catchment-scale vulnerability assessment, runoff projection and strategic policy design for declining glacier-fed water resources. In addition to estimating changes in water availability, such frameworks should evaluate the trade-offs, cost-effectiveness, greenhouse gas implications and potential maladaptive outcomes of the proposed interventions. This is particularly important where water harvesting or storage projects alter downstream groundwater levels, potentially benefiting some users while reducing water access to others. Safeguard mechanisms must therefore consider affected groundwater users, groundwater-dependent ecosystems and prime agricultural land, including measures such as compensation, alternative water access, abstraction control and recharge zone protection. In transboundary basins, these issues require particular attention because monitoring responsibilities, data sharing, allocation rules and staged revision of management measures may need to be formalized through legal agreements. Benefits from comprehensively implementing these measures include enhancing water security without transferring risks across sectors, regions or generations while helping to sustain the livehoods and ecosystem functions that support approximately 250 million people. Delayed or insufficient action would further threaten the water security and long-term sustainability of glacier-fed dryland basins and their inhabitants.
In this way, integrated basin management can move beyond isolated engineering responses. Its value lies in linking glacier monitoring, ecosystem protection, groundwater safeguards, infrastructure operation and urban water planning before glacier-fed water supplies become less reliable.
Conclusion
Climate change is accelerating glacier melt and depleting ice reserves in the Asian Water Tower. Glacier-fed river flows are becoming more variable in both volume and timing, while population growth and continued development are increasing the demand for reliable supplies of good-quality water. Historical hydrological records may no longer provide an adequate basis for estimating future runoff and peak flows. Water storage, release, sharing and allocation arrangements therefore need to be reconsidered, together with the governance rules and safeguards used to manage risk, particularly in transboundary basins where questions of responsibility and sovereignty may arise.
These challenges require coordinated short- and long-term action across upper, middle and lower catchments. Adaptation to changing water availability should be combined with stronger efforts to reduce greenhouse gas emissions, protect and enhance carbon stores and slow glacier loss. Long-term collection and sharing of data on glaciers, river flows, groundwater, ecosystems and related hazards would improve water use efficiency and support better coordination of water security measures. Rules governing water capture, storage, release, allocation and use should also be updated to account for greater hydrological variability. Governance arrangements and safeguards need to anticipate poorly designed interventions, maladaptation, inequitable outcomes and implementation failure.
Applying these measures across glacier-fed basins would help sustain the livelihoods and ecosystem functions that support approximately 250 million people. Delayed or insufficient action would further threaten the water security and long-term sustainability of dryland cities, river basins and their inhabitants.
Open peer review
For open peer review materials, please visit https://doi.org/10.1017/dry.2026.10051.
Author contributions
Collected and curated the data: Z.W. and X.J.; contributed to conceptualization: C.L., C.X. and L.C.S.; designed the research: C.L. and M.L.; performed the analysis and prepared the original draft: Z.W. and X.J.; provided resources: C.L., M.L. and B.F.; supervised the research and acquired funding: C.L. and M.L.; writing – review and editing of the manuscript: Z.W., X.J., C.L., C.X., L.C.S., M.L. and B.F.
Declaration of interests
The authors declare no competing interests.
Data availability statement
Glacier outlines were obtained from the Randolph Glacier Inventory version 7.0 (RGI 7.0 Consortium, 2023; https://doi.org/10.5067/F6JMOVY5NAVZ), using the Central Asia, South Asia West and South Asia East regions. Major river basin boundaries were obtained from the GRDC Major River Basins dataset, 2nd revised edition (GRDC, 2020). River networks were derived from HydroRIVERS version 1.0 and HydroBASINS Level 4 data were used to delineate the interior drainage region of the Tibetan Plateau (Lehner and Grill, Reference Lehner and Grill2013; https://doi.org/10.1002/hyp.9740). Country boundaries and lake distributions were obtained from the Natural Earth 1:10 m Admin 0 – Countries (Natural Earth, 2022) and Lakes + Reservoirs datasets (Natural Earth, 2021), respectively .
Funding statement
This research was jointly funded by the National Natural Science Foundation of China Project (grant W2412142, W2412136, 42571166), the Ordos Desertification Control and Sustainable Development Academician Expert Workstation, the 111 Project of China (B23027), and National Key Research and Development Program of China (2025YFE0202800). This study contributes to the Global-DEP II (Global Dryland Ecosystem Program Phase 2).
Open access
Comments
March 20, 2026
Dear Editor of Cambridge Prisms: Drylands:
We are pleased to submit our manuscript entitled “Managing glacial ablation in High Mountain Asia to sustain dryland cities” by Dr. Changjia Li et al. for consideration as a Perspective in Cambridge Prisms: Drylands.
This study focuses on dryland cities in High Mountain Asia, where water supplies depend predominantly on upstream glacier meltwater. With global warming accelerating cryospheric changes, regional glaciers are projected to retreat rapidly and may eventually disappear, posing significant threats to water security in dryland cities. Increasing water availability due to glacial melt often accelerates socio-economic development, which then boosts water demand—a classic positive feedback loop that can precipitate the earlier arrival of “peak water” and drive the system toward unsustainability. This mutual reinforcement is recognized as a major challenge in High Mountain Asia river basins such as the Indus, Ganges, Brahmaputra, and Pearl River, where increasing demands due to population and economic growth outpace the temporary gains from climate-driven water surpluses. Drawing on these insights, we propose integrated watershed management strategies linking upstream, midstream, and downstream regions: upstream efforts focus on preserving ice reserves and mitigating glacier ablation; midstream actions aim to enhance carbon sequestration and bolster water retention; and downstream strategies prioritize efficient water-resource management. We contend that through such a coupled human-natural systems approach—blending systemic, market, engineering, and ecological solutions—can we decouple development from water scarcity and ensure long-term water security.
We believe this manuscript is well suited to Cambridge Prisms: Drylands, as it offers a synthesis of cryospheric change, hydrological processes, and dryland sustainability within a unified framework. The Perspective provides both conceptual insights and practical implications, contributing to interdisciplinary dialogue and informing policy-relevant strategies for managing water resources in climate-sensitive dryland regions.
As potential referees, we suggest the following experts:
1.Professor Xin Li, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, China. Email: xinli@itpcas.ac.cn.
Professor with strong expertise in cryospheric science and integrated watershed.
2.Professor Jian Sun, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, China. Email: sunjian@itpcas.ac.cn.
Professor with strong expertise in dryland ecosystems and climate–water interactions.
3.Professor Weicai Wang, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, China. Email: weicaiwang@itpcas.ac.cn.
Professor with strong expertise in glacial lake dynamics and related hazards.
This manuscript has not been published previously and is not under consideration elsewhere. All authors have approved the manuscript and agree to its submission to Cambridge Prisms: Drylands. The authors declare no competing interests.
Thank you for your consideration. We look forward to your response.
Sincerely,
Mingyang Lv
Institute of Space Earth Science, Nanjing University,
Suzhou, China
Postcode: 215163
mylv@nju.edu.cn