CHANGES IN GLACIATION OF THE BALKHASH-ALAKOL BASIN OVER THE PAST 60 YEARS

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1 CHANGES IN GLACIATION OF THE BALKHASH-ALAKOL BASIN OVER THE PAST 60 YEARS I. Severskiy Слайд 1

2 Glacier Systems of the Balkhash-Alakol basin

3 Research Results Monitoring the Mass Balance of the Tuyuksu Glacier The Tuyuksu glacier remains degrading. Throughout 56-year observations, a negative annual mass balance was observed 42 times. The glacier surface (averaged for the entire area) reduced by 24 m since 1956 and the volume of melted ice amounted to 58 million m 3. Слайд 3

4 Cumulative Mass Balance of the Tuyuksu Glacier During the 1950s and 1960s, the glacier remained relatively stable, sharp degradation began in

5 Dynamics of the Tuyuksu Glacier Mass Balance It is characterized by parallel trends of winter and annual balances and sharp (threefold) decrease in winter balance in Since the early 1990s, there is a stable positive trend of winter balance. mm w.e. Years Winter Balance Summer Balance Annual Balance Слайд 5

6 Reasons for Accelerated Degradation The reasons for the accelerated degradation of glaciers in 1970s is abnormally high temperature during the ablation period and a dramatic (more than threefold) reduction of the winter mass balance. In this period, the rate of glacierized area reduction in Zailiyskiy Alatau exceed 1.2 percent per year vs. 0.8 percent per year which is an average observed during the last 50 years. Winter Mass Balance Dynamics for the Tuyuksu Glacier Changes in the Rate of Glacierized Area Reduction in Zailiyskiy Alatau, percent per year Слайд 6

7 GLACIATION DYNAMICS OVER THE LAST 60 YEARS Слайд 7

8 CHANGES OF GLACIERIZED AREA IN ILI-KUNGEI GLACIER SYSTEMS During the last half-century, glaciation in the concerned basins changed linearly with quite similar degradation rates. 8

9 Area (km 2 ) CHANGES OF GLACIERIZED AREA IN THE KAZAKHSTAN S PART OF JUNGAR ALATAU y = x R² = y = x R² = Year South 2 - West 3 - North 4 - East 5 - Total

10 CHANGES OF GLACIERIZED AREA OF GLACIER SYSTEMS Changes of glacierized area in Balkhash Alakol basin, 1955/ /12 Glacier systems:1- Northern Ili; 2-Jungar; 3-Upper Ili The average rate of glacierized area reduction amounted to 0.76, 0.75 and 0.73 percent, respectively 10

11 Conclusion Monitoring data for the Tuyuksu Glacier mass balance generally demonstrates the dynamics of glaciation in the region as a whole. Before the early 1970s, the glacier remained relatively stable. A sharp acceleration of glacier degradation began in 1973 and is due to a combination of abnormally high air temperatures in the ablation period and a dramatic (more than threefold) reduction of the winter mass balance from 1973 to A sharp acceleration of glacier degradation, which is typical for the WGMS network globally, was observed during the last decade.

12 Conclusion During the last half-century, glaciation of the concerned glacial systems changed linearly with similar rates of degradation. Within each glacial system, the highest rate of degradation was observed for the glacierized area of the outer (peripheral) mountain ranges; the minimum rate was observed for the intra-mountainous areas, as well as orographically-closed basins in the Eastern periphery of mountainous countries. If the current climatic conditions remain, a vast majority of glaciers in the Balkhash-Alakol basin might melt by the end of the 1980s. The disappearance of glaciers will inevitably lead to changes in the hydrological regime, as well as to the worsening of water and food security problems in the countries of Central Asia.