The experts of the subsidiary of “National Agrarian Science and Educational Center” JSC – “Fisheries Research and Production Center” LLP spoke about the importance of hydrological and hydrochemical research in reservoirs.
Kasymkhanov Aiybek Makhambetovich, head of the integrated fisheries laboratory of the Altai branch of the “Fisheries Research and Production Center” LLP made an online consultation on the topic “Hydrological and hydrochemical studies of reservoirs of international importance in the Yertis basin”. The speaker pointed out the importance of conducting hydrological and hydrochemical studies in water bodies. He cited brief information from the history of the development of hydrology, spoke about the impact of hydropower operations on the ichthyofauna. During the online consultation, detailed answers were received in the field of hydrological and hydrochemical studies.
The East Kazakhstan region is one of the most affluent and water-rich region of the Republic of Kazakhstan, which is determined by its natural and climatic conditions. The water resources of the region include: 1017 rivers, 1968 lakes, about 75 reservoirs and small ponds.
The Yertis basin is one of the largest fishery basins in the Republic of Kazakhstan, stretching from the north-west to the southeast for more than 1,500 km. This is a rather complicated morphologically macro-system, including such reservoirs of international importance as Lake Zhaisan, Buktyrma reservoir, Shulbinskoye and Ust-Kamenogorsk reservoirs, as well as the Yertis river. Currently, there are 36 fish species in the ichthyofauna of the reservoirs of the basin, among which there are both mass economically valuable fish and valuable rare and small species of fish.
Primary materials on the hydrology of water bodies are obtained at the East Kazakhstan Branch of the “Kazhydromet”, processed, analyzed by specialists of the Altai Branch of the “Fisheries Research and Production Center” LLP. Data submission is carried out in accordance with the "Rules for the preparation of biological studies for the use of wildlife" approved by order of the Minister of Environment and Water Resources of the Republic of Kazakhstan dated 04.04.2014 N. 104-Ө.
The hydrological regime of water bodies in different water years (low-water, medium-water, and high-water) affects the size of the commercial stock and the qualitative composition of ichthyocenoses. In dry years, not only energy and agriculture suffer from water shortages, but also fisheries.
The largest fishery reservoirs are Lake Zhaisan and the Buktyrma reservoir, hydrologically they comprise one reservoir, therefore the level regime is the same for them. Fluctuations in the water level in bodies of water depend on the volume of water of the flowing rivers, evaporation, and the volume of the reservoir discharge.
In the long-term aspect, low-water periods were observed in 1991, 1992, 2008-2009, 2012, and high-water periods were observed in 1994, 1995, 2002, 2014-2019. 2016 can be characterized as the most high-water year (393.95 mbs).
The Ust-Kamenogorsk Reservoir was created in 1952 with the aim of developing energy, water transport and water supply. The level regime of the Ust-Kamenogorsk reservoir is completely artificially regulated, determined by the operating mode of the Bukhtarma and Ust-Kamenogorsk hydroelectric power stations, as a result of which it is often unpredictable and unstable, even during one day, in some cases its fluctuations reach 1.0 m.
The Ust-Kamenogorsk Reservoir is a prime example of the impact of the hydrological regime on fish stocks. The features of the reservoir - significant water exchange, cold water, the almost complete absence of littoral - make it unsuitable for creating a high-number ichthyofauna complex.
The Shulba reservoir was formed in 1989 and is the third, last in the Upper-Yertis cascade of reservoirs. The hydrological regime of the Shulba reservoir is fully subject to artificial regulation; during the year, the level of 240 mbs is maintained, but in April-May, the reservoir is discharged, providing spring releases of water to flood the Ertis floodplain in Pavlodar region.
The water regime of the Ertis river section from the SPHS to the border with the Pavlodar region largely depends on the costs of the Shulba HPS in particular, on the regime of spring releases for flooding the Pavlodar floodplain and transit passage of spring flood waters. Under conditions of unregulated river runoff, natural floods rose slowly and also subsided. At present, natural floods have been replaced by artificial ones. As a result, its duration was reduced, the increase in the water level in the river, as well as its decline during releases occurs rapidly within 10-15 days, the summer flood is weakly expressed.
Hydrochemical studies
The emergence and development of mankind is inextricably linked with water in a variety of aspects, both biological and social. People have always sought to settle where there were sources of water suitable for drinking, irrigation, craft needs, and also near rivers, lakes, seas, which could be used as transport routes. From ancient times, people were interested in where the water came from in the world around us, why it is different in properties, how it can be used with greater benefit. The formation of hydrochemistry as a science responded to the need to generalize the accumulated knowledge about the chemical composition of natural waters and its change in time and space, depending on physical, chemical and biological processes. Of course, this was preceded by the development of chemistry in general and the chemistry of aqueous solutions as the foundation for the development of hydrochemistry. The chemical composition of natural waters (atmospheric, river, swamp, underground, oceanic) is diverse and determined by the conditions of their location. The identification of this relationship in the works of many scientists, including V.I. Vernadsky, O.A. Alekin, A.M. Nikanorov, is the basis of classical hydrochemistry.
Hydrochemical studies in reservoirs of international importance in the Yertis basin are carried out according to the following components: gas composition (dissolved O2, CO2), nutrients (nitrites, nitrates, phosphates), pH, mineralization, general hardness, etc. The results obtained are compared with the standards for maximum permissible concentrations for fishery reservoirs. All the studied reservoirs by hydrochemical composition are favorable for the life of hydrobionts. If there are any non-significant deviations from the MAC norms, then they are mainly seasonal in nature and usually stabilize by the end of the summer.
