A diagram of why and how flooding occurs
When water swamps
land that is normally dry, this is called a flood. Floods are caused in lots of
different ways, but the main one in Australia is rainfall. A flood is a` natural
process, but people can affect flooding because of what they do.
Every flood is different in some way. Floods can occur at any
time and very quickly. Some floods may take days, weeks and even months to build
up and then release the water. Floods can come and go whenever they want to and
years can pass before another flood comes again. Big floods can also come in short periods of time.
In Australia, lots of people choose to live on low lying land called a flood plain. Flood plains are where the land is low enough to get flooded. Cities and other buildings have been built on flood plains too for the access to water and good farmland.
When rain falls over an area, some of the water is absorbed by the soil and plants. The rest of the water flows downhill. The water is called a runoff. The runoff flows to a point where it stops. This area is called the catchment.
Floods can also be caused by other things. From international reports, some floods have been caused by tsunamis. Large tides and storm swells can cause coastal flooding. Earthquakes, volcanoes or large landslides can also cause flooding. Dams and levees can also flood when they break or a flood has come but there is a high amount of water in it.
Heavy and powerful rainfall can occur suddenly and very quickly. These floods can occur in minutes or hours. These floods are called flash floods. Flash floods are linked to small catchment areas where there may be not much flow of water. As flash floods occur suddenly and quickly, they can be difficult to manage and dangerous.
In larger catchment areas, floods can take days, weeks and even weeks to build up. The runoff from these floods flow across land and then into gutters, dams, streams and rivers. These floods can cover land with water for a
long time. With these floods, there is more time to react and the things that we do to help are more effective.
Floods are a natural process; and our ecosystems, river systems and inlets have adjusted to depend on a strange pattern of floods. Plant species, like River Red Gums depend on the pattern of dry periods divided by lots of rain and flooding.
People’s activities can affect the way that floods work. People make a lot of changes to catchment areas as they clear land and build dams. This even includes building houses and cities. These things can change the impact of a flood. It could make it worse or help it.
land that is normally dry, this is called a flood. Floods are caused in lots of
different ways, but the main one in Australia is rainfall. A flood is a` natural
process, but people can affect flooding because of what they do.
Every flood is different in some way. Floods can occur at any
time and very quickly. Some floods may take days, weeks and even months to build
up and then release the water. Floods can come and go whenever they want to and
years can pass before another flood comes again. Big floods can also come in short periods of time.
In Australia, lots of people choose to live on low lying land called a flood plain. Flood plains are where the land is low enough to get flooded. Cities and other buildings have been built on flood plains too for the access to water and good farmland.
When rain falls over an area, some of the water is absorbed by the soil and plants. The rest of the water flows downhill. The water is called a runoff. The runoff flows to a point where it stops. This area is called the catchment.
Floods can also be caused by other things. From international reports, some floods have been caused by tsunamis. Large tides and storm swells can cause coastal flooding. Earthquakes, volcanoes or large landslides can also cause flooding. Dams and levees can also flood when they break or a flood has come but there is a high amount of water in it.
Heavy and powerful rainfall can occur suddenly and very quickly. These floods can occur in minutes or hours. These floods are called flash floods. Flash floods are linked to small catchment areas where there may be not much flow of water. As flash floods occur suddenly and quickly, they can be difficult to manage and dangerous.
In larger catchment areas, floods can take days, weeks and even weeks to build up. The runoff from these floods flow across land and then into gutters, dams, streams and rivers. These floods can cover land with water for a
long time. With these floods, there is more time to react and the things that we do to help are more effective.
Floods are a natural process; and our ecosystems, river systems and inlets have adjusted to depend on a strange pattern of floods. Plant species, like River Red Gums depend on the pattern of dry periods divided by lots of rain and flooding.
People’s activities can affect the way that floods work. People make a lot of changes to catchment areas as they clear land and build dams. This even includes building houses and cities. These things can change the impact of a flood. It could make it worse or help it.