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The main components of the AALS salt balance

The main input of the AALS salt balance is salt leaching from the ground. At the moment of inundation of the Arnasay depression, its bottom was occupied by saline lake or shors (13%), residual solonchaks (45%) and deserted alkaline soils (37,5%). The total salt content in the bottom layer at 0-1 m thickness was about 50,25 million tones (Mahmudova 2004a).
Besides, Kurbanov and Primov state that the south-east part of the Arnasay depression was occupied by salt Tuzkan lake, mineralization of which exceeded 90 g/l. According to the
Uzbek Hydrogeological Scientific Institute estimates, salt supply amounted to 0,85 million tones. It was concluded that in the process of flooding of the Arnasay depression by fresh water from the Chardara reservoir, an intensive interaction between salt contained in water and ground started and freely soluble chlorides, i.e. sodium and magnesium salts, washed away within a year. Therefore, more than half of all salts from the ground entered into the reservoir at the initial waterflood stage (Kurbanov and Primov 2006).
Chembarisov and Shamsiev consider salt inflow with collector-drainage water as the second input component of the salt balance of the Aydar-Arnasay lakes. Depending on dryness of the year and conditions of hydrotechnical melioration of irrigated areas, 7-10 thousand tones of water soluble salts comes to the AALS. During the collector-drainage water discharges from the Chardara reservoir to the lakes 2-8 thousand tones of salts enters in spite of the relatively low mineralization of the Chardara water (Chembarisov and Shamsiev 2007).
We are also interested in analyzing the main output components of salt balance. Exploring the literature, two main components were identified: a) settling out of hardly soluble salts and b) losses in the numerous shallow bays formed around the Aydar-Arnasay lakes system. Output components make up no more than 5% of the total input components. This results in the gradual salt accumulation in the lakes (Mamatov and Kurnanbaev 2006).

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