What are the hazards of mountain torrents?

Flash floods are the most harmful floods. When a large amount of water suddenly comes together, it will cause flash floods. Because a large amount of water is gathered in an area, the impact of mountain torrents is often very strong, and floods will take people, cars and even houses away. 1976, the biggest flood in American history occurred in the Grand Thompson Canyon in Colorado. In less than five hours, the storm brought more rainfall to this area than the sum of the regular rainfall in this area all year round. At ordinary times, the Great thompson river is just a shallow and gentle river, which instantly turns into an unstoppable torrent, bringing a lot of water into the canyon at a speed of 880,000 liters/second. At that time, thousands of campers gathered in the canyon to celebrate the 0/00th anniversary of the founding of Colorado. The flood broke out so quickly that people didn't have time to sound the alarm. In this flood, * * 139 people died.