КАЧЕСТВО ГИДРОЛОГИЧЕСКИХ УСЛОВИЙ ДЛЯ ПРИВЛЕЧЕНИЯ РЫБ В УСТЬ-МАНЫЧСКИЕ РЫБОХОДНЫЕ КАНАЛЫ

Abstract

Purpose: quality assessment of hydrometric conditions for attracting anad-romous fish migratory along the river Western Manych in the fish passage channels of the Ust-Manych waterworks. Materials and methods. The factual basis of the study was the data of hydrological surveys carried out on the Ust-Manych fish passage channels, designed to allow fish spawners to pass to their spawning grounds. Generally accepted methods and techniques were used while conducting surveys, processing experimental data, their analysis and generalization. Results and discussion. Data have been obtained and calculations of hydrological characteristics have been made in the sections of the river Western Manych, corresponding to the location of the entrances to the fish channels, for two and three-month periods of the spring-summer spawning run of migratory fish. Differences in the values of water levels in the downstream of the Ust-Manych waterworks depending on the duration of the observation period were determined. Experimental data and calculated dependences to determine the average flow rates in the control sections for a wide range of changes in flow rates and water levels were obtained. The determined hydrological data of the river and the hydrometric data of fish passage channels constituted an empirical basis for assessing the quality of conditions for attracting fish from the river Western Manych to the entrances to the canals. It has been found that the quality indicator of conditions at different ratios of the values of the factors of influence for one fish passage channel was 27.3–45.3 %, and for the second channel it varies within 15.1–21.6 %. Conclusions. Data were obtained on hydrological values characterizing the section of the river Western Manych from the Ust-Manych waterworks to the alignment of its confluence with the river Don. An assessment of the hydrometric conditions quality for attracting fish migrating along the river to spawning grounds at the entrances to fish passage channels is made.