Potential impacts of a warming climate on water availability in snow-dominated regions

Abstract

All currently available climate models predict a near-surface warming trend under the influence of rising levels of greenhouse gases in the atmosphere. In addition to the direct effects on climate--for example, on the frequency of heatwaves--this increase in surface temperatures has important consequences for the hydrological cycle, particularly in regions where water supply is currently dominated by melting snow or ice. In a warmer world, less winter precipitation falls as snow and the melting of winter snow occurs earlier in spring. Even without any changes in precipitation intensity, both of these effects lead to a shift in peak river runoff to winter and early spring, away from summer and autumn when demand is highest. Where storage capacities are not sufficient, much of the winter runoff will immediately be lost to the oceans. With more than one-sixth of the Earth's population relying on glaciers and seasonal snow packs for their water supply, the consequences of these hydrological changes for future water availability--predicted with high confidence and already diagnosed in some regions--are likely to be severe.

Spatiotemporal patterns of High Mountain Asia's snowmelt season identified with an automated snowmelt detection algorithm, 1987–2016

“…Many catchments receive the majority of their yearly water budget in the form of snow -particularly at high elevations (Barnett et al, 2005). Both the volume of snowfall and the timing of snowmelt play crucial roles in the efficacy of water provision for downstream users, as many applications -such as agriculture and hydropower -rely on consistent and predictable water availability.…”

“…1, inset). The interaction of these climatic regimes with the complex topography of HMA -particularly the vast elevation gradients -creates a diverse set of snowfall regimes (Cannon et al, 2014;Kääb et al, 2012;Immerzeel and Bierkens, 2012;Gardner et al, 2013;Kapnick et al, 2014;Barnett et al, 2005;Dahe et al, 2006;Takala et al, 2011;Cannon et al, 2017).…”

“…The long-term trend in HMA of a shortened and earlier melt season will impact downstream populations who rely on the consistent timing and volume of spring and summer runoff (Archer and Fowler, 2004;Barnett et al, 2005). Already the impacts of precipitation intensification and shifts in the snowmelt season have been felt in many regions (Barnett et al, 2005;Stewart, 2009). These trends are likely to continue as tem- peratures rise across HMA, and each major catchment will feel the impacts of a shortened snowmelt season regardless of changes in the start and end dates of melt.…”

Statistical study to identify the key factors governing ground water recharge in the watersheds of the arid Central Asia

“…At present, the world is experiencing an undeniable temperature increase and thereby inevitably is faced with various environmental problems, among which the acceleration of global water cycle processes induced by increasing temperature is prominent (Menzel and Burger 2002). The consequences of these hydrological changes for future water availability, predicted with high confidence and already diagnosed in some regions, are likely to be severe (Barnett et al 2005), especially in the arid zones.…”

Glacio-hydrological melt and runoff modelling: a limits of acceptability framework for model selection

“…Snow melt dynamics play an important role in the hydrological behaviour of mountainous catchments (Barnett et al, 2005;Jeelani et al, 2012) and as such observation data relating to the accumulation and melt of snow are important for evaluating the performance of glacio-hydrological models. No direct observations of snow accumulation or melt exist for the Virkisá river basin and so instead, satellite snow cover data (MOD10A1 product) from the Moderate Resolution Imaging Spectroradiometer 5 (MODIS) (Riggs and Hall, 2015) were used.…”