The changing water cycle: the need for an integrated assessment of the resilience to changes in water supply in High‐Mountain Asia

Abstract

Water sourced from Asian mountains is vital to the survival of an estimated 1.4 billion people, but current and anticipated changes in snow, ice cover, and precipitation patterns may threaten these supplies and, in turn, the food security of tens of millions of people. Despite the severity of this developing environmental hazard, the relative importance of each component of the water cycle still needs more detailed study so that those communities who will experience the greatest extremes in supply can be identified. Specifically, data showing how the contribution of meltwater varies with increasing distance downstream are lacking for many mountain catchments, although the use of stable isotope tracers provides some hope in this regard. Imprinted on regional-scale hydroclimatological controls of water availability are local-scale cultural beliefs and practices that have evolved over centuries, which determine who is able to access water supplies, for how long, and for what purpose. Building the resilience of human populations and the environment to future changes in water supply therefore depends on effective interdisciplinary team working to develop an understanding of the complex interactions between physical, socioeconomic, cultural, and historical factors, and that can only be properly realized if local communities are considered as an integral part of the research team. Developing simple and practical methods for water management, storage, and societal adaptation that are appropriate to the socioeconomic and political conditions of mountain-dwelling communities will only be sustainable if they are built on this integrated knowledge base.

Manifestations and mechanisms of the Karakoram glacier Anomaly

“…The anomalous glacier behaviour in the Karakoram and its neighbouring regions is not only a curiosity in an epoch dominated by glacier retreat. The glaciers' importance for regional water supplies 7,8 (Figure 4.5), and the cultural and religious value attributed to glaciers by the local communities and their traditional practices 99 • In thermally controlled surges, changes in basal temperature promote a positive feedback between ice deformation, basal melt, pore water pressure, and sliding. This mechanism is comparatively slow, and leads to seasonally independent surge initiation-and terminationphases that are several years long.…”

Closing the Adaptation Gap in Mountains

“…However, given the dynamic nature of climate and social conditions, particularly over longer timescales, adaptations must be capable of flexibility in response to new information. These issues can be addressed through adaptation planning processes that engage with available scientific informationkey references include the ''High Mountain Areas'' chapter in the Intergovernmental Panel on Climate Change (IPCC) Special Report on the Oceans and Cryosphere in a Changing Climate (Hock et al 2019) and the forthcoming ''Cross-Chapter Paper on Mountains'' in the IPCC Sixth Assessment Report-as well as community members whose familiarity with specific mountain regions can complement scientific assessments of locally relevant climatic changes (Quincey et al 2018;McDowell et al 2021). Because adaptation needs change over time, planning processes should attend to local priorities and knowledge bases on an ongoing basis, with flexibility comprising a core tenet of capacity-building approaches.…”

The State of Remote Sensing Capabilities of Cascading Hazards Over High Mountain Asia

“…In the southeast, the climate is defined by heavy rainfall during the summer monsoon, while the western region receives significant rain and snow from winter westerlies. HMA has the largest concentration of glaciers outside of the poles and Alaska and serves as a freshwater reservoir for over a billion people (Immerzeel et al, 2010;Quincey et al, 2018). Global Land Ice Measurements from Space (GLIMS) and the Randolph Glacier Inventory (RGI) v6.0 have identified 95,536 glaciers across HMA (Zhao et al, 2014).…”