Disadvantages of Underground Transmission over Overhead Transmission. 1  Underground transmission line cable is costlier than overhead transmission. 2  The maintenance cost of underground cables is higher than over head transmission. 3  Capital cost of Overhead Transmission lines are cheaper than underground transmission line.
the average annual rainfall for Canada is 60.33 cm. That is alot! Any average is going to be a meaningless because Canada covers over 9 million sq/kms, extending from the Nor â¦ th Pole to below the 49th parallel and both east and west coasts of North America.
In Canada, a severe thunderstorm is defined as having wind gusts of greater than 90 kilometres per hour (56 mph), hail with a diameter of greater than 20 millimetres (0.79 in), rainfall of greater than 50 millimetres (2.0 in) in an hour or greater than 75 millimetres (3.0 in) in three hours, or tornadoes.