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The Aydar-Arnasay lakes model development

The following section focuses on the description of the model of the Aydar-Arnasay lakes using the STELLA software. As it was described in the methodology section¹⁹, this software seems to be a suitable tool for development of the Aydar-Arnasay lakes model.
Before introducing the main idea and structure of the model, we deem it reasonable to reiterate the primary research question. Our overarching goal is to identify which of the elaborated water management scenarios is the most probable for the future development of the Aydar-Arnasay lakes system.
“The AALS future development” directly depends on the level of regional cooperation between Central Asian republics and some environmental factors, such as change of the regional climate. These factors will influence the future characteristics of these lakes, including the hydrological features, maintenance of fisheries, conservation of biodiversity, i.e. wetlands of international importance designated as a Ramsar site and various birds and fish species inhabiting these lakes.

1. Model structure and basics

The main goal of the model is to test the elaborated water management scenarios of the Aydar-Arnasay lakes system future using the STELLA software in order to find the most probable scenario for the future development of these lakes system.
Research resulting in creation of the model consisted of two main stages. They are:

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  CEU eTD Collection
  The “desk-based” stage of the research was focused on literature review and unstructured interview with experts; this stage gave rise to the detailed analysis of the AALS and identification of the factors most influential on its development.
  
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  The “field study” stage was aimed to gather more particular information about factors and processes important for the Aydar-Arnasay lakes development. Analysis of the archival materials was also conducted at this stage.
  

As the result of these stages, the simulation model was constructed using the STELLA software. Finally, series of experiments were carried out to test the elaborated water management scenarios.

¹⁹ See section 3.3.2.1

Figure 24 shows the model screenshot presenting the basic structure of the AALS model.
Figure 24. The model screenshot demonstrating the basic block of the model
The present model contains two main modes:

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  CEU eTD Collection
  Mode I “Model optimization”; this mode is designed to find out how much water discharge is needed for the maintenance of the Aydar-Arnasay lakes taking into account future change of the regional climate; the results obtained will lay a groundwork for the elaboration of the quantitative characteristics of the water management scenarios which will be put into the model;
  
• 
  Mode II “Scenario analysis”; this mode is designed to test the elaborated water management scenarios in order to find the most probable one for the future development of the AALS.
  

The present model is formulated through quantitative assessment of the inflows, i.e. water discharges from the Chardara reservoir, water discharges for the drainage network and inflow from rainfall; outflows, i.e. evaporation and percolation, and storage changes which are represented by AALS volume fluctuations.

1.