RIVERS

By: Sergio Gutiérrez

Fernández

River Basin -It is an area of land drained by a river and its

tributaries

Watershed

It is the higher land

which forms the

boundary of the river

basin, and which

separates two river

basins

Source-The point at

which

a river begins

Tributaries

They are small stream or river flowing into the

main river

Confluence The place

where a tributary joins the main river

MouthThe end of

a river

Processes of Erosion:-Attrition: material is moved along the bed of a river

-Corrasion: Fine material rubs against the river bank-Corrosion: Some rocks forming the banks and bed of a river are dissolved by acids-Hydraulic action: The sheer force of water hitting the banks of the river

Processes of

Transportation:-Traction: Large rocks and boulders are rolled along the bed (of the river)-Saltation: Smaller stones bounced along the bed-Suspension: Fine material, light enough in weight to be carried by the river

-Solution: Dissolved material is transported by the river

Results of the rivers shaping the land:

-The rivers can

erode the land

.

-The rivers can transport material.

Oxbow Lake:

Flood Plain: The flat area of land over which

a river meanders.

Levees Delta

-An embankment

raised to prevent

a river from

overflowing.

-The deposited material will slowly build upwards and outwards

Hydorlogical Cycle: -It is the natural recycling of

water between the oceans, atmosphere and land.

Distributaries:

-Deposition blocks the main channel

of the river.

Hydrology-It is the study

of water.

Flooding

Drought

-An extreme surplus of

water on the land

-An extreme shortage of water

How does the river basin system work

Precipitation

-Is the amount of rainwater which will

become the run-off of a river

Discharge:

-It is the amount of

water in a river

channel at a given

time, measured in

cumecs.

The flood hydrograph

-It is the relationship between precipitation and the level of

a river

River Flooding

Causes:

Results:

-Type and amount of precipitation, type of soil and underlying rock, land use of the river basin and the human activity.

-Can put lives in danger, damage

property and disrupt people’s

normal way of life.

How might the flood risk be reduced?

-It often needs

considerable amounts of

money and high levels of

technology.Results of a river flooding in developing countries

-Is a combination of natural factors and human mismanagement. Although flooding normally brings benefits, extreme floods, especially in developing countries, can be disastrous.

TheEnd