SOLUTION OF TASKS OF ENGINEERING PROTECTION AGAINST DEBRIS FLOWS ON UNDER-EXPLORED WATER CHANNELS (THE CASE OF THE BADDON RIVER BASIN, REPUBLIC OF NORTH OSSETIA-ALANIA)

Abstract

Under force-majeure circumstances in the system of pressure pipelines and the Zaramagskaya Hydroelectric Station-1 an emergency mode water discharge with a 65 cu.m/s discharge rate from the daily regulation reservoir of the right tributary of the Ardon river in the Baddon river basin will be required. In the Baddon river estuary and along the discharge transport channel there are buildings and infrastructure of the Mizur settlement, which experienced catastrophic effects of sediment/water debris flows in 1967 and 1996, whose quantitative characteristics remain unknown. The Baddon river has not been hydrologically explored. Emergency discharge exceeding the critical level (~30 cu.m/s) will cause a sediment/water debris flow with a ~85 cu.m/s discharge, which is less than those of possible debris flows of a 0.5‑1% probability, coming up to the estuary. The drawn-up design of engineering protection, based on the parameters of a debris flow, occurring under the natural conditions developed up to 2012 (Qc=140 cu.m/s; p=1380 kg/cu.m) at the 10 km long stretch in the valley upstream and downstream from the discharge point. Protective works: debris flow chute, bank protection walls (at the technical water intake structure), gallery at the location of the water discharge «plume» (above the autoroad).