The rivers of Central Asia, nourished by the cryosphere, supply up to 90% of water to the plains characterised by arid and semi-arid climate. Water is sourced from liquid precipitation, seasonal snow pack, glacier and ground ice (buried ice, rock glaciers, permafrost). The observed climatic warming has resulted in 30-50% loss of glacier area and volume since the 1950s and degradation of permafrost. Currently, in the glacier-fed catchments, stronger glacier and ground ice melt compensates for the lack of precipitation in summer and discharge in the headwater catchments is increasing in response to the intensifying glacier melt. However, after the peak water has passed, the exhaustion of ice resources will threaten regional water supply potentially affecting 140 million people. Already now, lowland catchments experience water shortages due to poor irrigation practice and these are expected to worsen.
Water contamination by industrial, domestic and particularly agricultural sources is one of the most pressing regional environmental problems. Deglaciation and associated decline in streamflow are expected to have a negative impact on water quality in rivers as concentrations of pollutants are expected to increase and pathways to change in response to water availability, shifts in peak flow, increasing temperature and changing precipitation regimes. The effects of these changes on lakes and reservoirs, into which the rivers eventually flow, are unknown. There are two potential effects: (i) reduced river flow and increased evaporation provides less dilution of pollutants in agricultural and urban areas; (ii) increased water temperature has a direct impact on pathogen growth and survival. It is possible that water will be contaminated by trace metals, released by the uncovered bedrock and melting ground ice.
Analysing hydrochemistry and water quality from glaciers to deserts
In 2019, project SCWAI was launched to address the questions about the potential impacts of deglaciation on water quality in Central Asia. SCWAI works in the four reference catchments in Kazakhstan, Kyrgyzstan, Uzbekistan and Tajikistan. It aims to (i) characterise hydrochemistry and water quality in the glacierized catchments in Central Asia along the elevation continuum from glaciers to deserts using consistent and comparable measurements; (ii) develop water quality models – HYPE Central Asia – for these catchments; (iii) examine how multiple stressors, induced by climate, glacier, landuse and water management change, affect water quality at present and in the future under different climate change scenarios; and (iv) make recommendations for the development of adaptation strategies in the region.
Reference catchments in Kazakhstan, Kyrgyzstan, Uzbekistan, and Tajikistan
SCWAI is funded by the UK Global Challenges Research Fund and works in collaboration with the research network CARAWAN. SCWAI is led by the University of Reading, UK. The partner organisations is Central Asia are: Kazakhstan Institute of Geography and Water Safety; Central-Asian Institute for Applied Geosciences, Kyrgyzstan; Institute of Water Problems, Hydropower and Environment, Tajikistan; National Glaciological Centre, Tajikistan; Institute of Geology and Geophysics, Uzbekistan; National University of Uzbekistan.
The development of research links between scientists in the UK and Central Asia, capacity building and stakeholder engagement are important components of the project. Training in water quality analysis has been provided both in the field and at the University of Reading to a number of early and middle career researchers from the Central Asian countries. The stakeholder engagement events are planned in 2021.
Training at the University of Reading, UK
The preliminary results from SCWAI were presented at the EGU Conference in 2020:
Yapiyev et al. (2020) Water quality in glacierized and urbanized alpine catchments of Central Asia: What happens after the ice? dx.doi.org/10.5194/egusphere-egu2020-802
Contact: Professor Maria Shahgedanova