Transcript Chapter 27 Waiting for the Rains: The Effects of Monsoons in South

Waiting for the Rains:
The Effects of Monsoons
in South Asia
Write the definition of monsoon
Winter & Summer Monsoons
Answer box One
Box 2
Box 3
Box 4
a. Changes in Atmospheric Pressure Create
Monsoons
i. Falling cool air creates high pressure areas.
1. Due to the downward pressure, very
little surface air can rise into the upper
atmosphere to form clouds.
2. Typically sunny days and no rain.
ii. Rising warm air creates low pressure areas.
1. If the rising air is moist, clouds form
bringing rain.
a.
b.
c.
d.
Atmospheric Pressure: the weight of the
atmosphere pressing down on any point of the
surface of Earth. Air sinks in high-pressure areas,
and few clouds form. Air rises in low-pressure
areas to form clouds that produce rain.
Monsoon: a seasonal wind. Summer monsoon
winds in South Asia usually bring rain to that
region.
Orographic effect: the precipitation that occurs
when moist air rises up the side of a mountain. As
the air rises, it cools down and releases most of its
moisture as rain or snow.
Rain shadow: a dry area on the downwind side of
a mountain.
Box 5
Box 6
Orographic Effect
Importance of Monsoons
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http://www.bbc.co.uk/learningzone/clips/mon
soon-rains-support-the-indianrainforest/8987.html
Read section 27.3 & determine
which image & picture belong
III. The Wet Months in Dhaka,
Bangladesh
a. One of the World’s Wettest Capitals
i. Most of Bangladesh lies on a river delta that
rises dangerously high during monsoon
rains.
1. Result: possible flooding causing
difficult rice cultivation.
ii. Dhaka:
1. Located in the center of Bangladesh.
2. One of the wettest climates on Earth.
3. Up to 80 inches of rain fall each year.
4. Most rain during summer months.
5. Weather is dry from November to April.
iii. Tropical cyclones (aka Hurricane)
1. City is lashed by high winds and waves
because city is situated at sea level.
b. Life Depends on the Rains
i. Bangladesh’s economy depends on agriculture.
1. 3/5th’s of the population farm the rich delta
soil, relying on hopefully consistent
monsoon rains to water their fields.
a. If late many crops suffer.
b. If too much rain, flooding occurs. In
Dhaka, flooding is an issue.
i. Planting and harvesting becomes
impossible.
ii. Traffic halts.
iii. Schools and businesses shut down.
iv. Floodwaters pollute city’s drinking
supply, encouraging disease to rapidly
spread.
v. Dhaka life lesson: rains that bring life
to local fields can also end life in the city.
Read section 27.4 & determine
which image & picture belong
IV. The Dry Months of Jodhpur,
India
a. A City on the Edge of a Desert
i. Known as the “Blue City” because many of the
houses are painted blue.
ii. Jodhpur sits at the eastern edge of the Thar Desert
in northern India.
iii. Region is leading producer of cattle, spices, and
grains.
iv. Typical semiarid climate, with hot, dry weather
throughout most of the year.
v. Average yearly rainfall = 14 inches
vi. Summer monsoons bring rain from June to
September.
vii. Average temperature stays above 60 degrees.
The “Blue City”
b. Water is a Critical Resource
i. 80% of people around Jodhpur are farmers.
1. Farming is difficult in this dry region.
2. Farmers depend on monsoons for water.
3. If too little water, crops fail and drinking water is in
short supply.
4. When food runs out, some families survive by eating
samas, a wild grass. Disease spreads easier when
people are weak from hunger.
ii. The people of Jodhpur have adapted to their climate.
1. They raise livestock capable of surviving on native
plants when crops fail.
2. Farmers use drip irrigation (drip water directly onto
roots) to conserve water.
a. South Asia:
i. Monsoons affect the climate of South
Asia.
ii. Differences in atmospheric pressure
between the land and sea cause the
Summer Monsoons bringing welcome
rain and deadly floods to coastal cities.
iii. The orographic effect shapes the
climate of South Asia.
b. Other regions also have monsoons:
i. November to April: northern
Australia.
ii. May to July: West African coast.
iii. Middle of summer: Arizona.
c. Everywhere: the climate affects human
activities.
Climate Zones Around the World
 Create
Climagraph on Clarksville &
answer questions
Monsoon- Frog & Mouse
Review for Quiz
Monsoon Definition
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Monsoon- a seasonal wind that hits South Asia
twice a year
Summer Monsoon = wet air, heavy rains
Winter Monsoon = dry air, drought
Orographic Effect
Rain Shadowdroughts
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Take quiz over information
# 2 is B
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Edmodo- assignment
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