The authorities in southern Russia repeated warnings on Tuesday for residents to evacuate their homes in regions hit by severe spring flooding. In Tyumen in western Siberia on the border with Kazakhstan, Governor Alexander Moor posted a video on the Telegram messaging service. “All of you know the danger. Take your valuables! Move without delay to a safer place!” he said. The Ishim river, a tributary of the Irtysh, which is itself a tributary of the Ob, has burst its banks. The Ob flows north into the Arctic Sea To the west, another village had to be evacuated by the city of Orsk in the Orenbu…