GRADE 8 GEOGRAPHY
Unit 1: Factors influencing temperature & rainfall
Factors influencing temperature and rainfall
1.1 Distance from the equator (latitude)
1.2 Distance from the sea
1.3 Height above sea level (altitude)
1.4 Ocean currents and winds
1.5 Mountains (relief)
1.1. Distance from the Equator (Latitude)
Temperature
Cooler/Colder
temperatures are
found near the
poles (North and
South Poles).
Hot temperatures
are found near the
equator.
Hot and cool
temperatures are
found near the
Tropics.
Rainfall
In polar areas we
can expect snowfall
because the air is
colder and
descends.
Because it is warmer
around the equator,
we can expect more
rainfall here.
1.2. Distance from the Sea
Inland areas are Hotter in
Summer and Colder in
Winter; and receive LESS
rainfall due to the distance
travelled from the sea.
SEA Temperature changes at a
slower rate than LAND
temperature; therefore
coastal areas will have milder
winters & cooler summers.
1.3. Height above sea level (Altitude)
Temperature:
The higher you go, the colder it becomes because air temperature depends
on air density.
Air at higher altitudes: less dense and colder (convection)
Air at lower altitudes: more dense and warmer (conduction)
Rainfall:
The higher the altitude, the cooler it becomes, therefore cooling moisture
condenses and forms rain droplets.
Mountain areas receive more rainfall than flat or lower areas.
1.4. Ocean Currents and Winds
COLD
BENGUELA
CURRENT
(from the
Poles) cools
down the
WEST COAST
of South
Africa
WARM
AGULHAS
CURRENT
(from the
Tropics &
Equator)
warms up the
EAST COAST
of South
Africa
LESS rainfall
along the
WEST COAST
of South
Africa due to
the COLD
current.
MORE rainfall
along the
EAST COAST
of South
Africa due to
the WARM
current.
1.5. Mountains (Aspect)
1.5. Mountains
Warmer slopes have
higher temperatures so
they receive more rain.
The closer the
slopes are to the
equator, the warmer
they are.
The closer the
slopes are to the
poles, the colder
they are.
Leeward slopes (facing
away from the equator)
have less rainfall.
Slopes close to the poles
have snowfall.