Algae blooming in the Kamianske Reservoir

According to observation data obtained at the drinking water intake in the Kamyanske reservoir in the village of Auly, the basic patterns of water blooming were specified. Water abstraction in here is performed from the depth of 8-9 m, which roughly corresponds to a mid-point of the maximum depths. It was determined that the number of algae per unit volume is very large - significantly higher than at the water intake of the Dnieper Water Supply Station (DWSS), which is located in the downstream of the Kyivska HPP. In some cases, it may exceed 1000 million in 1 dm3. During the study period, a decrease in algae amount was recorded, mainly, starting from 2018. The largest algae amount per a volume unit is usually observed in September, i.e. later than in the surface layer of water. The largest algae amount was recorded in September of 2010 and 2014. The factors that contributed to the development of algae at this time are given. Such factors were primarily high air and water temperatures, as well as low cloud cover. There is some delay in changing weather conditions. From June to November, blue-green algae are dominant in the water intake in the village of Auly, the share of which in August-October reaches 95-99%. From December to April, diatomic algae are dominant. The share of green algae is the highest in summer, but it does not usually exceed 2-3% of the total. The significant development of algae in the Kamyanske Reservoir is confirmed by remote sensing data. According to satellite data, it was found out that in this reservoir the largest blooming is observed in the place of water intake location. The dependence of water blooming on hydrometeorological conditions, in particular the direction of wind currents is also shown. The dominance of the northeast wind over the Kamyanske Reservoir in the summer causes a wind setup to the water intake, which results in the increase in the number of algae cells per volume unit.