Degree of Master of

Results obtained

After calculations of the AALS water-surface during 1969-2009, impressive results have been received. The results of the calculations and their illustrative representation are presented in Table 2 and Figure 12. Also it should be noted that along with the calculation of the water-surface area, the Arcview program enabled calculation of the AALS water volume.
Table 2. Change dynamics of the AALS water-surface area and volume during 1969-2009¹¹

	1969	1973	1978	1983	1988	1993	1998	2003	2008	2009
Water surface, km^2	2180	1959	1630	1771	2143	2504	2890	3500	3640	3752
Volume, km^3	17,5	15,6	12,3	13,4	17,7	25,0	28,7	36,9	41,2	44,3

Figure 12. Change dynamics of the Aydar-Arnasay lakes system during 1969-2009¹²

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Figure 12 clearly demonstrates trends of the AALS historical development which was described in the first section of the present chapter. In this graph we can observe that 1969- 1993 was a period when these lakes existed as for the storage for collector-drainage water coming from the Golodnaya Steppe irrigation area and the water-surface of the lakes system was increasing slowly. Table 1 indicates that during 1969-1993 the water surface area increased by 300 km² while during 1993-2009 – by 1200 km². Such huge increase was caused by the change in the Toktogul regime operation, i.e. electricity generation during the winter time resulted in increased water discharges from the reservoir. Concerning volume changes, the same trends can be identified. In the period of 1969-1993 the volume did not increase significantly, from 17,5 km³ to 25 km³. In contrast, we can examine that since 1993 volume has been increasing more rapidly, from 25 km³ to 43,4 km³ in 2009.

¹¹ The following calculations were made using the Arcview program

¹² Based on the results obtained the graph has been created in the Excel program by the author

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Summing it all up, this exercise let us visualize the historical stages of the Aydar- Arnasay lakes system development. Furthermore, we could analyze how this system was evolving during forty years in terms of water-surface area and volume changes. This exercise has laid a significant groundwork for our further research, namely, elaboration of the water management scenarios and the creation of the AALS model.
Based on the literature found in the archives, results obtained from the unstructured interview and use of different satellite images the major historical features of the Aydar- Arnasay lakes system (AALS) development have been examined, i.e.:

• 
  The main historical stages of the Aydar-Arnasay lakes have been identified and described by the author;
  
• 
  Change dynamics of the AALS water-surface area and volume in 1969-2009 has been examined by accomplishment of the practical exercise using the various GIS methods;
  
• 
  The present chapter has attained one of the objectives established by the author and laid a significant groundwork for the following research chapters.
  

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