presentation in earth science

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Water disaster’s

Flash Floods

• A flash flood is a rapid  flooding of geomorphic low-lying areas washes, rivers, dry lakes and basins. It may be caused by heavy rain associated

with a storm, hurricane, or tropical storm 

• Flash flooding occurs when precipitation falls too quickly on saturated soil or dry soil that has poor absorption ability. The runoff collects in low-lying areas and rapidly flows downhill. Flash floods most often occur in normally dry areas that have recently received precipitation.

– 2010: April-May - The great Nashville flood. Water in the Cumberland river rose, flooding downtown Nashville and surrounding areas.

– 2010: June 11 – The Little Missouri River rose over 20 feet in only a few hours, killing at least 20 people.

– 2010: July 24 – Dehli lake dam on the Maquoketa River breached after 9 inches (230 mm) of rainfall. 15 ft. chunks of highway broke off and swept down river, and steel guard rails were flapping like paper streamers in the wind. Created further flooding, farther down river from where it spilled into the Mississippi River.

– 2010: Mid–July till Mid-August – Pakistan's three provinces were affected during the monsoon rains when dams, rivers and lakes overflowed killing 1400 people and affecting 3.5 million people.

Tsunamis• A tsunami is a gigantic wave, also called a tsunami wave train, and at one time referred to as a tidal wave, a series of water waves caused by the displacement of a large volume of a body of water, usually an ocean.

Tsunamis in the world• 2010: Chile

Destruction provoked by the 2010 Chile earthquake and tsunami, in Pichilemu,O'Higgins Region, Chile.The seismic event in the southern Pacific produced waves measuring 1.8–9 meters along the Sanriku Coastline of northeastern Honshu in Japan.

• 2011: New ZealandOn February 22, 2011, a 6.3 magnitude earthquake hit the Canterbury Region of the South Island, New Zealand. Some 200 kilometres (120 mi) away from the earthquake's epicenter, around 30 million tonnes of ice tumbled off the Tasman Glacier into Tasman Lake, producing a series of 3.5 m (11 ft) high tsunami waves, which hit tourist boats in the lake.

• 2011: Pacific coast of JapanOn March 11, 2011, off the Pacific coast of Japan, a 9.0 magnitude earthquake produced a tsunami 33 feet (10 m) high along Japan's northeastern coast. The wave caused widespread devastation, with an official count of more than 25,000 people confirmed to be killed/missing. The highest tsunami which was recorded at Ryōri Bay, Ōfunato, reached a total height of 97 feet (30 m).In addition the tsunami precipitated multiple hydrogen explosions and nuclear meltdown at the Fukushima I Nuclear Power Plant. Tsunami warnings were issued to the entire Pacific Rim.