Irrigative assessment of Sasyk water quality

• Main Authors: S.M. Urasov, V.A. Kuzmyna
• Format: Article
• Language: English
• Published: Odessa State Environmental University 2019-12-01
• Series: Український гідрометеорологічний журнал
• Subjects: irrigative assessment, water quality, sasyk, detailed typification of irrigative water, salinization, alkalinization
• Online Access: http://uhmj.org.ua/index.php/journal/article/view/138

The transformation of the salt-water liman Sasyk into a fresh water reservoir through its separation from the sea by a dam and connection with the Danube by a canal caused certain ecological problems. One of them was that during the first decades the expected water irrigation conditions were not achieved because of salt infiltration from the bottom sediments. Use of high-salinity water led to soil salinization. As a result, Sasyk ceased to be considered as an object for irrigation purposes. At present, the process of Sasyk water quality formation stabilized and the need for land irrigation is still of great importance. The authors of the researches devoted to solving the environmental problems of Sasyk classify the irrigation properties of water as average and maximum values of mineralization. However, these properties can change significantly over the year and therefore the water may belong to different irrigation categories (classes). The purpose of this study is to evaluate the irrigation properties of Sasyk water and their variability based on the hydrochemical observations conducted near the village of Trapivka, at base pumping station GNS-2 during warm periods of a year from 2007 to 2017. The article presents an overview of different methods of irrigative water assessment and a detailed typification of the irrigative water using the water typification suggested by Aliokin O.A. The research includes the evaluation of the Sasyk water quality as per the studied methods. The authors discovered the fact that mineralization of Sasyk water during a warm period is within the 1-3 g/dm3 range in 90-95% of cases under study and only in 5-10% of those its value is less than 1 g/dm3. The ratio of main ions in Sasyk water may be of the following subtypes: IIa (30%), IIb (50%), ІІIb (10%) and ІІIc (10%). The mineral composition is mainly represented by the toxic salts such as NaCl, Na2SO4, MgSO4. Their content in the water does not exceed 2.0 g/dm3. Among the toxic salts NaCl is the one that prevails. Under normal conditions the mineralization of the water and the content of sodium and magnesium ions in Sasyk contribute to salinization and soil alkalinization. To provide safe irrigation of all types of soil using the water from Sasyk its chemical melioration and dilution with low-mineralized water is required. At present, the irrigative properties of Sasyk water (mineralization, composition of toxic salts and their concentration) allow its use of for irrigation of light, permeant and drained soils.