causes of flooding?

Question

i am giving off a presentation on how this disaster ,flooding occurs. pl. help

Answer 1

flooding comes from rain

Answer 2

A very simple answer would be that flooding is caused by too much rain but there's a lot of other factors that play a contributory role.

For example, if there has been a lot of rain recently then the ground may already be saturated and river levels could be high. In such circumstances it doesn't require all that much extra rain to cause flooding. The new rain can't be absorbed by the saturated ground so instead it quickly runs off into the rivers and streams causing them to rise rapidly.

A similar thing happens when intense rain falls, even if it's for a short time and the total amount of rain isn't that much. Because it's raining heavily there's not enough time for the water to soak into the ground so it runs off and quickly fills the rivers, sometimes leading to flooding. This happens more frequently on a local level and is exacerbated by hills, valleys etc where the water quickly enters the river systems.

If there's a lot of snow on the ground and it thaws rapidly this can cause extensive flooding, particularly downstream of where the snow lies. It's quite possible for flooding to occur in one area even when the weather is dry because snow upstream has melted.

A further problem associated with snow melt is that a lot of water can melt in a short space of time and if the ground beneath the snow is frozen then the meltwater doesn't soak into the ground and rapidly makes it's way down to lower ground.

We as humans also have a role to play in causing flooding. When we build parking lots, highways etc we cover the natural ground so again, the water isn't soaked up but instead runs off. In times of heavy rain this can overload the drainage systems and lead to flooding.

In other areas where we cut down woodland and forests it exposes the thin soils, water can quickly erode the exposed soil and once again, there's little ground remaining into which the rainfall can be absorbed.

Some coastal areas are particularly prone to flooding and if the right conditions combine there can be devastating floods. For example, there's approx 2 high and low tides each day, during the spring and fall the tides are higher than winter and summer, in the days after a full moon and new moon tides are higher. At certain times this means that the tides are much higher than normal, if this coincides with a string wind blowing in off the sea and / or an area of low pressure it can cause a 'tidal surge' which can overtop flood defences and lead to massive flooding.

There are other factors as well but I hope this gives you something to go on.

Answer 3

It rains a lot and then the city's drainage system gets backed up, leaving the water nowhere to go. Flooding.

Answer 4

Too much rain. That's one.

But after a while, there will be another reason for flooding. Global warming is melting all the glaciers in the north and south pole. And we caused global warming. so I guess the new reason would be us. We are flooding our homes.

Answer 5

Living in an area devasted by Hurricane Katrina I would have to say poor drainage systems ( improper pumping capacity), pumps can't handle the amount of rain happening all at one time, the trash and debris clog up the system. Oh yeah and can't forget about levees breaking.

Answer 6

Lack of border control, allows Mexicans to keep flooding across the border.

Answer 7

I can only think of one cause of flooding, and that's too much rain.

Answer 8

flooding comes from to much rain in a short period of time.

Answer 9

Too much rain and not enough proper drainage to accomodate the excess.

Answer 10

LOTS & LOTS & LOTS OF RAIN.
Tideal surge
sudden ice melt