River basics
What do we call the place where a river begins?
Name one of the three main parts of a river.
Upper course, middle course or lower course.
Name one source of river water.
Rain, melting snow or groundwater.
Does water usually flow faster on a steep or gentle slope?
Steep slope.
True or false: All rivers flow into the sea.
False. Some flow into lakes or other rivers.
What do we call the place where a river ends?
Mouth
Which comes first: upper course or lower course?
Upper course.
What happens to snow in spring?
It melts.
Which can carry bigger stones: fast water or slow water?
Fast water.
Name one river that flows through Tallinn.
Pirita River is one example.
Name one river in Estonia.
For example: Emajõgi, Pärnu River, Narva River, Võhandu River or Pirita River.
In which part of a river is the land usually steepest?
Upper course.
In which season do Estonian rivers often have floods?
Spring.
What is erosion?
When flowing water wears away rock or soil.
True or false: Rivers always flow in a straight line.
False.
What is a meander (jõelooge)?
A bend or curve in a river.
In which part of a river does it usually become wider and start to bend more?
Middle course.
What is a flood?
When river water overflows its banks and covers normally dry land.
In a river bend, where does sand usually collect: on the inside or the outside?
On the inside of the bend.
A river has very little water after a long dry summer. Give one reason why.
There has been little rain, and less water is entering the river.
What is an oxbow lake?
A lake formed when a river bend is cut off from the main river.
Name two differences between the upper and lower course of a river.
For example: upper course has a steeper slope and narrower channel; lower course has a gentler slope and wider channel.
Why can a river flood after several days of heavy rain?
A lot of rainwater enters the river, causing the water level to rise.
Why does a river bend become bigger over time?
Water erodes the outside bank and deposits material on the inside bank.
A river carries sand and small stones. What may happen when the water slows down?
The sand and stones can settle on the riverbed. This is deposition.