Types+of+floods

=ANDRES LINCE G. Tropical Storms= In 1969, a tropical storm caused extensive floods in Virginia. Hurricane Camille had spent most of its initial energy over the Gulf of Mexico. As it neared Virginia, it met a line of large thunderstorms coming down from the north. The warm, moist air carried by Hurricane Camille clashed with the cold northern storms, meeting over the Tye and Rockfish river valleys. Together, the two weather systems caused huge sheets of rainfall. In some areas, hard rain accumulated 31 inches in only six hours. The Rockfish River rose 30 feet. Rivers and creeks in the region’s valleys could not hold all the water, so it spilled over the banks and covered the lowlands. Water then cascaded into the valleys. Rain softened a large chunk of a nearby mountain, causing it to slide into the valley, carrying boulders, mud, and thousands of giant trees. When the [|landslide] ended, farms were buried under 30 feet of soil and earth. More than 125 lives were lost in the flood, while many others were left without homes. Camille was an example of one of the most common causes of floods - heavy rains that come with tropical storms. Such storms form over the warm waters of the tropics, so they are full of moisture. When the right conditions form, bringing these giant storms toward land, many inches of rain usually fall. The heavy precipitation is too much for the streams and rivers to handle, causing water to overflow and produce inland floods. Many of these tropical storms form over the Gulf of Mexico. In May 1990, heavy rainstorms caused floods in Texas, flooding more than 200 square miles along the Trinity River. A record 100,800 cubic feet of water passed through Lake Livingston Dam, destroying crops far east. More than 700,000 acres of Louisiana farmland were covered with water. According to some scientists, the record floods of 1990 were caused by global warming, the theory that the earth’s atmosphere traps heat near the earth, slowly warming the earth. This greenhouse effect may have heated the water in the Gulf of Mexico, causing it to evaporate faster. With more water vapor in the lower atmosphere, small storms escalated into large systems with lots of moisture. These storms moved over the southern United States and released a torrent of rain that led to massive flooding. If the global warming theory is correct, sea levels will rise three to five feet in 60 years. Coastal areas may be partially submerged underwater or easily flooded. Other seasonal weather conditions can also cause floods. In September of 1982, large amounts of rain fell in Utah, followed by heavy winter snows. In May, an unexpected heat wave melted the snow, causing water to cascade down the mountain slopes. The water raced into Salt Lake City and through much of the plains. The next winter brought another heavy snowfall. Now that they were prepared for what was to come, residents filled over one million sandbags and placed them on riverbanks to keep them from overflowing in the spring. In May, a heavy thunderstorm hit, starting a new series of floods. The water swelled the Great Salt Lake, bursting through dikes and flooding wetlands, marshes, roads, parks, and homes. Fortunately, very few people or livestock died because of the warning people had beforehand. The flood had also built slowly, giving people lots of time to prepare. The earth has seven oceans that cover almost three-fourths of its surface. Naturally, wind and other events caused ocean water to sometimes overflow. When this happens, flooding on the shores occurs. Ocean storms can dump lots of water on a coast, raising the sea level in that area. These are known as storm surges, and cause coastal flooding. Coastal flooding usually occurs as a result of severe storms, either tropical or winter storms. Ocean waves intensify on the open ocean, and these storms make surface water much choppier and fierce than normal. Raging winds can create huge waves that crash on unprotected beaches. In the winter of 1978, the northeastern United States coast saw severe flooding that resulted from high winds, high tides, and a storm surge. High winds coincided with unusually high waves. South of Boston, Massachusetts, waves came over a seawall built to protect houses in the region. These wild waves destroyed the houses into rubble. Low-lying towns were also flooded with ocean water and ice. Coastal flooding can also be caused by long, low sea waves caused by volcanoes, landslides, earthquakes, or explosions. These waves are tsunamis. These giant tidal waves are difficult to detect on the open sea, so seismologists must keep track of seafloor movements that warn of possible tsunamis. These waves are extremely dangerous because of their high speeds. Deeper water means faster-traveling waves. When the sea floor is several miles below, waves can travel more than 600 miles an hour. As they near shallow water, they slow down, but build in height. Some tsunamis can be 50 to 100 feet high when they hit shore. Tsunamis can travel thousands of miles without weakening, their initial energy being transferred along the open ocean to coastlines. They can pass through islands or coral reefs without stopping, but usually die or bounce back after hitting a large land mass.
 * Seasonal Flooding**
 * Coastal Flooding**
 * Tsunamis**

Floods A flood happens when too much rain falls. Storms can cause floods. In a flood, water from rivers flows over the land. Flood water enters houses and other buildings. A flood is a a great flowing or overflowing of water onto land that is not usually submerged. A flood happens when too much rain, brought by storms and strong winds, falls and cannot be absorbed by the soil. Rivers burst their banks and the water spills onto the land. Strong winds blowing across the sea make huge waves that surge onto the land and flood coastal areas. Types of Floods River Floods Rivers floods happen when rivers and streams cannot carry away all the extra water that falls as rain or comes from melting snow. The water rises in the rivers and streams and overflows onto normally dry land. Floods destroy farmland, wash away people's houses and drown people and animals. Towns and cities are flooded too.
 * sofia dominguez**

Coastal flooding can be caused by strong winds blowing waves onto the land. Hurricanes and major storms produce most coastal floods. Very high tides and tsunamis also flood the coasts. In many countries, large groups of people live along the coasts and for these people coastal flooding can be very serious. Thousands of people have been drowned in coastal flooding in many parts of the world. Flash Floods A flash flood is a quick flood caused by a sudden cloudburst or thunder storm. Huge amounts of water fall in a short time and in cities and towns the drains overflow and roads become flooded. Flash floods also happen in mountainous areas, where steep slopes cause the water to travel at high speeds. The rushing water erodes the soil, washing it away down the slopes. Flash floods often occur rapidly and with little warning. Humans may also cause floods Floods sometimes occur when artificial structures such as dams fail. If the dam is poorly designed or built in a place where earthquakes and landslides occur, the dam will break and the water floods the land. One dam failure in the United States of America occurred in 1972 when a dam used to store waste from a coal mine as well as water, collapsed after three days of rain. The flood drowned 118 people and caused $65 million in damages. When floodwaters rise slowly people have time to get ready. They can move themselves and some of their property to higher ground, or build barriers to keep the water out of their homes. Sometimes the water rises quickly and people and cars get caught in the flood. Water gets into buildings causing damage, things are washed away, and people have to leave their homes.