2. Elements
The elements of something are the different parts that make it up.
Do you remember the parts of a river?
The source, the mouth, and the channel
3. Source
The source of a river is where it emerges from the earth to become a river.
Or, where the river begins.
Most rivers begin in the mountains.
The Manzanares River in Madrid has its source in the Navacerrada mountain
pass in the Guadarrama mountain range. If you want to see the source, you
can visit it from Manzanares el Real.
4. Mouth
The mouth of a river is where the river ends. It can empty into an ocean, sea,
lake, or another river.
The Manzanares is a tributary, which means that it ends in another river, the
Jarama. The Jarama is a tributary of the Tajo (Tagus River).
Some rivers have a landform called a delta at the mouth.
Ebro Delta
5. Channel
The channel is where the river flows.
The path of a river is called its course, and it can be divided into three
sections:
The upper course (close to the source); the middle course (the central
section), and the lower course (close to the mouth).
6. Characteristics
A characteristic gives us information about something. When we describe
people, we can use physical characteristics (tall, strong, agile) and personal
characteristics (intelligent, kind, funny, etc.)
When we talk about rivers, we mention three characteristics. These give us
information about the river.
The characteristics are: Length, Regime, and Discharge.
7. Length
The length of a river is the distance from its source to its mouth.
The rivers of Spain have their source in mountain ranges. If the mountain
range is close to the mouth, the rivers are short. Ex. Cantabrian basin
8. The rivers of the Meseta and the Guadalquivir Depression have their source in
mountain ranges far from the sea. This means that the rivers are long.
The Tagus River (Tajo) has its source in the Sierra de Albarracín in Teruel and
travels a long way before it finally empties into the Atlantic Ocean.
9. Discharge
The discharge is the amount of water passing through the river at a given
time.
The discharge of a river can change from one season to another.
10. Regime
The regime is the discharge variation throughout the year.
A river has got a stable regime when its discharge is constant (the same all
year.)
It has a variable regime if the flow changes a lot. There is more water during
periods of heavy rain, and less during dry periods.
11. The characteristics of a river depend on
two main factors:
The relief affects a river’s length and speed. If the source in the mountains is
far from the sea where the river drains (its mouth), the rivers are long. When
a river starts in mountains close to the sea, it is short.
The climate affects a river’s flow (discharge) and regime. Rivers that travel
trhough rainy regions have greater flow (more voluminous) and rivers that
pass through dry regions have got variable regimes.
12. Now you know how these factors affect
the characteristics of the rivers.
Look at the map. Which rivers are longer? Which are shorter? Which are
stable? Which have a variable regime? Which have a heavy discharge (a lot of
water)?