Hydrometeorological conditions of formation and destruction of multilayer ice on slopes of the reservoir at the Kiev pumped-storage station

Abstract

1. The process of formation of multilayer ice on a slope with a 1∶4 gradient of the reservoir of the pumped-storage station depends on the temperature of the water being pumped into the reservoir, stable negative air temperatures, and effect of the wind. 2. Freezing over of the ice prism on the slope of the storage reservoir occurs at a temperature of the water being pumped of 0.2–0.5°C and ceases at a water temperature of 0.5–0.6°C regardless of the stability of negative temperatures. 3. Melting of the ice prism and the formation of ice overhangs begin when the temperature of the pumped water increases to 0.6–0.7°C. The length of the ice overhangs formed during melting between the stiffeners reached 4.0–4.5 m and above the stiffeners 1.0–2.2 m. 4. The maximum width of the ice prism during the period of operation of the pumped-storage station reached 14.0 m and the height 3.0 m. 5. Stiffeners on the slope with a 1∶4 gradient promote the formation of an ice prism with a width 1.5–2.2 times greater than in the absence of stiffeners. 6. The amount of ice forming on the reservoir can be reduced by increasing the temperature of the water being pumped into it to 0.7–1.0°C. This can be achieved by providing average discharges of 400–600 m3/sec at the Kiev hydrostation.