1. Rivers
SEC ONE TEXTBOOK
PAGE 101

3. What is a river?
A river is a natural watercourse,
usually freshwater, flowing
towards the sea.
Without the hydrological cycle,
rivers cannot be formed.

4. Is this a river?

5. HYDROLOGICal CYCLE

7. HYDROLOGICal CYCLE

8. HYDROLOGICALHYDROLOGICAL
CYCLECYCLE
SURFACE
RUNOFF
INFILTRATION
CONDENSATION
TRANSPIRATION AND
EVAPORATION
PRECIPITATION

9. HYDROLOGICAL CYCLE
• Precipitation – water
from clouds come to the
Earth’s surface as rain,
snow and hail
• Transpiration – plants
release water vapour into
atmosphere

10. HYDROLOGICAL CYCLE
•Surface Run-off – rain
that falls on Earth’s
surface flows over land
• Condensation – water
vapour rises, cools and
changes into tiny water
droplets

11. HYDROLOGICAL CYCLE
• Infiltration – water
that soaks into the soil
subsurface
• Percolation – water
moves further down
into the underlying soil
after infiltration

12. HYDROLOGICAL CYCLE
•Throughflow –
infiltrated water that
flows sideways in
the soil subsurface
• Interception –
water is absorbed
by trees

13. Water flows from highlands to lowlands due to the
pull of gravity.
River System
River sourceRiver source: The place at which the river
begins. Usually found in mountainous areas or
highland.
TributaryTributary: Streams and rivers that join the
main river
Rivercourse River mouthRiver mouth:
The place at
which a river ends
into the sea

14. RIVER SYSTEM
• Source – the
starting point of a
river
• Mouth – the ending
point of a river
• Drainage Basin –
The area drained by
a river and its
tributaries

15. RIVER SYSTEM
•Confluence – the
point at which a
tributary joins the
main river
• Watershed – The
boundary formed
by the edges of the
drainage basin