Declining glaciers endanger sustainable development of the oases along the Aksu-Tarim River (Central Asia)

Abstract

Tarim River basin is the largest endorheic river basin in China. Due to the extremely arid climate the water supply solely depends on water originating from the glacierised mountains with about 75% stemming from the transboundary Aksu River. The water demand is linked to anthropogenic (specifically agriculture) and natural ecosystems, both competing for water. Ongoing climate change significantly impacts the cryosphere. The mass balance of the glaciers in Aksu River basin was clearly negative since 1975. The discharge of the Aksu headwaters has been increasing over the last decades mainly due to the glacier contribution. The average glacier melt contribution to total runoff is 30-37% with an estimated glacier imbalance contribution of 8-16%. Modelling using future climate scenarios indicate a glacier area loss of at least 50% until 2100. River discharge will first increase concomitant with glacier shrinkage until about 2050, but likely decline thereafter. The irrigated area doubled in the Aksu region between the early 1990s and 2020, causing at least a doubling of water demand. The current water surplus is comparable to the glacial runoff. Hence, even if the water demand will not grow further in the future a significant water shortage can be expected with declining glacial runoff. However, with the further expansion of irrigated agriculture and related industries, the water demand is expected to even further increase. Both improved discharge projections and planning of efficient and sustainable water use are necessary for further socioeconomic development in the region along with the preservation of natural ecosystems.

Modeling and analyzing supply-demand relationships of water resources in Xinjiang from a perspective of ecosystem services

“…After the "bonus period" of glacial melting, runoff will decrease significantly, and water resources will correspondingly decrease significantly. This is also a major problem for water resources in the future (Hartmann et al, 2016;Bolch et al, 2021).…”

Land Use Dynamic Changes in an Arid Inland River Basin Based on Multi-Scenario Simulation

“…The natural environment is the basis of land resources and is important in the process of rapid economic development [60]. In recent decades, in the context of global warming, the decline in glacier reserves in mountainous areas, the rapid growth of runoff and precipitation, and the accelerated melting of alpine snow cover have greatly increased the area of water bodies in the basin [61,62]. Significant increase in temperature and precipitation with global warming, receding glaciers and reduced snowmelt will have an impact on surface water in the study area.…”

Rio (1992) to Glasgow (2021): Three decades of inadequate mitigation of climate change and its slow onset effects

“…These changes are attributed to latitudinal, altitudinal, topographic, and geologic conditions, as well as to glacier type and properties (Chen et al, 2016;Li et al, 2016;Shahgedanova et al, 2020). Yet, an overall negative mass balance-both for the past and future-has been reported/ forecasted for most Central Asian glaciers (Chen et al, 2016;Li et al, 2016;Pohl et al, 2017;Bolch et al, 2022). In humanitarian terms, the receding Central Asian glaciers directly impact the living conditions of large rural populations, which are already vulnerable and often impoverished, and generally lack the financial or political capacity to overcome the changing environmental conditions (USAID, 2018).…”