Natural disasters当地震、火灾、沙尘暴、龙卷风等自然灾害发生时，人类才真正意识到，面对强大的自然威力，我们是多么的脆弱！Not many of us have experienced a natural disaster like a tornado. How would we cope in Hurricane Charley which hit Florida in the USA in 2004? In the west coast areas, 800,000 people were evacuated to escape winds which reached nearly 140 miles per hour. Some people refused to leave their homes. They filled the bathtub with water, put sandbags against the windows, brought everything inside and boarded up their windows. One man was sitting in his kitchen when the microwave oven flew across the room. His trailer home(旅行用活动住屋) was destroyed and when he walked down the road to the hospital, he discovered that it was also very damaged by the winds. At one nursing center, roofs were ripped off, windows shattered and doors pulled open. Everyone remained surprisingly calm under the circumstances. Over a hundred shelters were set up to help those in need. At one of these centers which held 100,000 people, the roof was ripped off. The US Government provided 120 tons of food for 250,000 meals to begin with and built a base camp with 500 shower units to help the stranded families. Insurance companies expect to pay out approximately US＄7.4 billion to repair the damage.Tornadoes are classified using the Fujita Scale. This gives ratings from F0 to F5. The system estimates the length of the tornado and the width of its path. Sometimes very large tornadoes are weak and small ones extremely violent. F0 means there might be some damage to chimneys, and shallow trees may be uprooted. The wind is 72 miles per hour, or gale force. At F5 the wind force is devastating and may reach 260 miles per hour. Houses can be leveled at the foundations and during one very violent tornado, six vehicles were seen in the air at once. About 1,000 tornadoes are recorded each year in the USA and there are probably a further 1,000 milder tornadoes which go unrecorded.In the past, tornadoes were always a surprise and many lives were lost because of this lack of knowledge. Today, the ability of meteorologists to understand weather patterns saves enormous numbers of lives.
