Reading comprehension

Causes of Floods Floods are second only to fire as the most common of all-natural disasters. They occur almost everywhere in the world, resulting in widespread damage and even death. Consequently, scientists have long tried to perfect their ability to predict floods. So far, the best that scientists can do is to recognize the potential for flooding in certain conditions. There are a number of conditions, from deep snow on the ground to human error, that cause flooding.When deep snow melts it creates a large amount of water. Although deep snow alone rarely causes floods, when it occurs together with heavy rain and sudden warmer weather it can lead to serious flooding. If there is fast snowmelt on top of frozen or very wet ground, flooding is more likely to occur than when the ground is not frozen. Frozen ground or ground that is very wet and already saturated with water cannot absorb the additional water created by the melting snow. Melting snow also contributes to high water levels in rivers and streams. Whenever rivers are already at their full capacity of water, heavy rains will result in the rivers overflowing and flooding the surrounding land.Rivers that are covered in ice can also lead to flooding. When ice begins to melt, the surface of the ice cracks and breaks into large pieces. These pieces of ice move and float down the river. They can form a dam in the river, causing the water behind the dam to rise and flood the land upstream. If the dam breaks suddenly, then a large amount of water held behind the dam can flood the areas downstream too.Broken ice dams are not the only dam problems that can cause flooding. When a large human-made dam breaks or fails to hold the water collected behind it, the results can be devastating. Dams contain such huge amounts of water behind them that when sudden breaks occur, the destructive force of the water is like a great tidal wave. Unleashed dam waters can travel tens of kilometers, cover the ground in meters of mud and debris, and drown and crush everything and creature in their path.Although scientists cannot always predict exactly when floods will occur, they do know a great deal about when floods are likely, or probably, going to occur. Deep snow, ice-covered rivers, and weak dams are all strong conditions for potential flooding. Hopefully, this knowledge of why floods happen can help us reduce the damage they cause.Definitions:natural disasters - things caused by mother nature that have potential dangerconsequently - as a resultsaturated - soaked completely throughabsorb - to use upoccur - to happencontributes - to providecapacity - the maximum amountdevastating - dangeroustidal wave - extremely large wavedebris - loose material that can cause damageUnleashed - to releasedestructive - devastating, dangerous Which of the following words are natural disasters? (More than one answer may be correct). flood earthquake plane crash hurricane Which of the following are included as causes for floods in the reading passage? droughts large lakes poorly built roads melting snow How does deep snow cause flooding? melting snow causes flooding too much rain causes flooding sudden warm temperatures combined with heavy rains causes flooding freezing water causes flooding A broken human-made dam is compared to what? a tsunami a tidal wave a broken ice dam overflowing Which of the following best describes how a frozen river can cause a flood. The ice in the river melts too quickly and causes a flood. The ice in the river cracks causing the water to overflow. The ice in the river cracks into piecesthat eventually create a dam causing the water to overflow. The water behind the ice dam collects and when the dam breaks, it causes flooding upstream. How far can dam water travel when it is unleashed from a broken dam? less than 10 kilometers tens of kilometers thousands of kilometers tens of thousands of kilometers downstream Why does saturated ground contribute to flooding problems? the ground cannot absorb more moisture the ground is too hard, so the water runs off the ground forms a kind of dam it remains frozen What kinds of problems can floods cause? death widespread damage destruction of plants and animals all of the above What is the most common natural disaster? flood fire wind damage rain How does melting snow cause problems related to flooding? it makes the rivers run too fast it makes the water too cold it causes pieces of ice to block the river it makes the level of the river rise fill in the blank Floods cause widespread damage. Unfortunately, there is little we can do to prevent flooding in some situations. There are several causes for flooding including deep snowmelt, icy rivers, and broken dams. First, when deep snow melts it creates large amounts of water. When heavy rain and sudden warm temperatures combine with the deep snow, floods can occur. Second, rivers that are covered in ice can cause floods when the ice melts. The ice pieces form dams that break and cause flooding. Third, human-made dams can break and cause devastating damage. The water from these dams can be as powerful as a tidal wave. Our best plan of attack against flooding is to recognize the potential for flooding in certain conditions. lightning drought storm rock slide tornado Tidal Wave volcano earthquake fire Which disasters are made of humans? / Which disasters are made of nature? human-made disasters fire pollution war animal extinction deforestation natural disasters hurricane tornado tsunami flood earthquake drought parched soil avalanche masses of snow tsunami tidal wave earthquake movements of Earth's crust tornado rotating column of air hurricane extremely strong wind