Flood

Floods are considered second only to wildfires as the most common natural disaster on Earth. Human changes to the environment often increase the intensity and frequency of flooding. Floods occur in all types of river and stream channels, from the smallest ephemeral streams in humid zones to normally-dry channels in arid climates.

About Flood in brief

Summary Flood Floods are considered second only to wildfires as the most common natural disaster on Earth. Human changes to the environment often increase the intensity and frequency of flooding. Floods occur in all types of river and stream channels, from the smallest ephemeral streams in humid zones to normally-dry channels in arid climates to the world’s largest rivers. Flooding in estuaries is commonly caused by a combination of storm surges and rising water leading the flood edge of the estuary to the edge of a river. The word ‘flood’ comes from the Old English flod, a word common to Germanic languages, and may also be applied to the inflow of the tide. Floods can happen on flat or low-lying areas when water is supplied by rainfall or snowmelt more rapidly than it can either infiltrate or run off. In one instance, a flash flood killed eight people enjoying the water on a Sunday afternoon at a popular waterfall in a narrow canyon. The deadly flood resulted from a thunderstorm over part of the waterfall, where the steep, bare rock slopes were common and the thin soil was already saturated. Flash floods are most common in normally- dry zones, the mostcommon type of flood is known as arroyos in the southwest United States and many other names elsewhere in the U.S. In the United States, flooding is most common caused by storm surges caused by winds, setting the flood water to arrive as it wets the sandy stream bed. As a result, higher flood water flows more slowly than later and higher flows advances more slowly, thus the flood becomes ever quicker as the flood flow moves downstream, until the flood rate is so great that the depletion of soil becomes insignificant by the time it reaches the flood bed.

The first flood water is usually caused by the first storm surges, which are often followed by a second storm surge that is followed by the third storm surge, which is usually the fourth storm surge. The fourth flood is often the fourth or fifth flood, and the fifth flood is the sixth or seventh flood, depending on the severity of the flood. The sixth flood is caused by an areal flood, in which the water overtops or breaks levees, resulting in some of that water escaping its usual boundaries, or it may occur due to an accumulation of rainwater on saturated ground in anAreal flood. Slow-rising floods most commonly occur in large rivers with large catchment areas. The increase in flow may be the result of sustained rainfall, rapid snow melt, monsoons, or tropical cyclones. Rapid flooding events, including flash floods, more often occur on smaller rivers, rivers with steep valleys, rivers that flow for much of their length over impermeable terrain, or normally- Dry channels. The cause may be localized convective precipitation or sudden release from an upstream impoundment created behind a dam, landslide, or glacier. Localized flooding may be caused or exacerbated by drainage obstructions such as landslides, ice, debris, or beaver dams.