Q:

How do floods start?

A:

Quick Answer

According to NOAA, most floods start with slow-moving thunderstorms, thunderstorms that travel the same path several days in a row, or hurricanes. Floating debris and ice sometimes form a temporary dam which causes the water to back up until the debris breaks free, releasing a wall of water and causing flooding downstream.

Know More

Full Answer

Some rivers flood seasonally with rains. Warm rains in mountain areas melt snow to increase the volume of water in the river. Hurricanes or tropical storms bring large amounts of rain inland and cause the flooding of streams and rivers.

Urbanization increases the flood potential. The covering of formerly grassy pastures with asphalt increases the runoff from two to six times. Urban flooding turns streets into rivers. A basement in an urban setting becomes a potential death trap due to flooding.

NOAA warns residents to know the flood dangers for where they live. Most floods occur with some warning, and it is important to evacuate on the recommendation of officials. Floodwaters of only 6 inches have the ability to knock a human off his feet. If the water is over 2 feet in depth, it will float an automobile. Each additional foot of water adds another 500 pounds of lateral force to move the vehicle downstream.

Learn more about Storms
Sources:

Related Questions

  • Q:

    How often do floods occur?

    A:

    The frequency of flooding depends on the region, although it is one of the most common natural disasters in the United States. Floodplains can flood every year, and floods are more common in the Midwest and coastal regions.

    Full Answer >
    Filed Under:
  • Q:

    When do floods occur?

    A:

    Floods occur when the volume of water contained by the shores of a body of water or the banks of a waterway exceeds the body's capacity. The water moves above and outward from the typical area it occupies. The major causes of floods are heavy rains, melting snow or a blockage of water flow in a river.

    Full Answer >
    Filed Under:
  • Q:

    Why do floods occur?

    A:

    Floods occur when the ground is incapable of absorbing water from rainfall, melting snow or ice. Each spring, many regions experience warmer temperatures along with heavy precipitation. This is the ideal combination for flooding. If the ground has not completely thawed, it is even more likely to flood as there is no place for the water to drain.

    Full Answer >
    Filed Under:
  • Q:

    How are floods measured?

    A:

    The National Weather Service measures floods using stream gauges in key locations across the country. During times of flooding, they measure how high the water has risen above the gauges to determine flood levels.

    Full Answer >
    Filed Under:

Explore