Water Availability in Central Asia – Societal Vulnerability to Changing Glacier and Snowmelt Runoff Contributions to Central Asian Rivers

Experimental pilot study with focus on the quantification of runoff components in the Ala-Archa catchment using stable isotopes and hydrochemical parameters, and on the derivation of socio-ecological vulnerability indices to changes in runoff.

Background and Objectives

The main rivers of Central Asia such as the Amudarya and Syrdarya provide the livelihoods of the people living in the semi-arid region of Central Asia. They originate in the Central Asian high mountains where glacier and snow melt contribute substantially to runoff generation. The economies of the riparian states rely heavily upon the use of the river water, mainly for irrigated agriculture and for hydropower generation. This makes them vulnerable to changes in river runoff regimes. Global climate change and the observed shrinkage of glaciers in the Tien Shan and Pamir raise the question about the spatio-temporal variability in glacier and snowmelt contribution to river runoff and potential changes in the runoff components.

The GlaSCA project aims at establishing an inter-disciplinary research consortium uniting German and Central Asian scientists which will (1) address the quantification of the glacier and snow-melt contribution to river runoff in the region and (2) assess the societal vulnerability to changes in runoff amount and seasonal distribution. The project will foster the existing and develop new collaborations among partners and beyond aiming at developing future research activities and proposals for the quantification of water availability and societal vulnerability in Central Asian countries.

Study Area and Methods

For the GlaSCA pilot study we will focus on the partly glacierised but easily accessible and well-monitored catchment of the Ala-Archa River (283 km2) located on the northern slopes of the Kyrgyz Range near Bishkek (Kyrgyzstan). We will estimate the contributions of glacier melt, snowmelt, groundwater and rainfall to river runoff and investigate their temporal and spatial variability using the analysis of stable isotopes and hydrometric measurements.

In a subsequent modelling exercise, we aim at validating and improving already existing hydrological models with the newly gained data and at understanding the processes which govern the glacier and snowmelt contribution to river runoff. The adequacy of process representation in the hydrological models will be investigated in order to put confidence in the future large-scale model applications.

In addition, we will analyse the vulnerability of down-stream communities, including different economic sectors and societal groups, to changes in water availability and in the variability of glacier and snowmelt contribution. Based on this knowledge, preliminary societal vulnerability indices will be derived, that can be applied for the assessment of global change impact on water resources in Central Asian countries.

The pilot study will put the consortium into a position to develop further research ideas and mature scientific proposals on the quantification of the Central Asian water cycle and the role of different water storage components for water availability and management. Furthermore, the assessment of the related socio-ecological vulnerability should be tightly linked in a decision-making framework with new insights on changes in the hydrological cycle.

Project Partners

• GFZ German Research Centre for Geosciences, Section Hydrology
• Helmholtz Centre for Environmental Research – UFZ, Department Catchment Hydrology
• United Nations University, Institute for Environment and Human Security (UNU-EHS)
• Central Asian Institute for Applied Geosciences (CAIAG), Department of Hydrology and Climate Research
• American University of Central Asia (AUCA), Tian Shan Policy Center

Associated partners:

• National hydrometeorological services of Kazakhstan, Kyrgyzstan, Tajikistan, and Uzbekistan

key publications :

He, Z., Vorogushyn, S., Unger-Shayesteh, K., Gafurov, A., Merz, B. (2017): The value of hydrograph partitioning curves for calibrating hydrological models in glacierized basins, (Geophysical Research Abstracts, Vol. 19, EGU2017-13577), General Assembly European Geosciences Union (Vienna, Austria).

He, Z., Unger-Shayesteh, K., Vorogushyn, S., Gafurov, A., Weise, L., Kalashnikova, O., Merz, B. (2017):Towards the improvement of model internal consistency using water isotope composition measurements in a glacierized basin, (Geophysical Research Abstracts, Vol. 19, EGU2017-16924), General Assembly European Geosciences Union (Vienna, Austria).

He, Z., Unger-Shayesteh, K., Vorogushyn, S., M. Weise, S., Duethmann, D., Kalashnikova, O., Gafurov, A., & Merz, B. (2020). Comparing Bayesian and traditional end-member mixing approaches for hydrograph separation in a glacierized basin. Hydrology and Earth System Sciences, 24(6). doi.org/10.5194/hess-24-3289-2020

He, Z., Unger-Shayesteh, K., Vorogushyn, S., Weise, S. M., Kalashnikova, O., Gafurov, A., Duethmann, D., Barandun, M., & Merz, B. (2019). Constraining hydrological model parameters using water isotopic compositions in a glacierized basin, Central Asia. Journal of Hydrology, 571. doi.org/10.1016/j.jhydrol.2019.01.048

He, Z., Vorogushyn, S., Unger-Shayesteh, K., Gafurov, A., Kalashnikova, O., Omorova, E., & Merz, B. (2018). The Value of Hydrograph Partitioning Curves for Calibrating Hydrological Models in Glacierized Basins. Water Resources Research, 54(3). https://doi.org/10.1002/2017WR021966

Final report :

Water availability in Central Asia - Societal vulnerability to changing glacier and snowmelt runoff contributions to Central Asian Rivers (GlaSCA) :

Funded: by International Bureau on behalf of the German Federal Ministry for Education and Research, funding period: 03/2015-02/2017