Maharashtra Board Class 11 Geography Chapter 4 Climatic Regions PDF Download

4. Climatic Regions

Use Your Brain Power!

Have you ever thought why there is difference in the skin colour of various peoples in the world?

Why all the people in the world do not eat same food?

Why there is a variety in clothing pattern and types too?

Even our houses are different.

How come flora and fauna are restricted to particular region?

Why different fruits are found in different places?

Geographical Explanation

As you know, there are five spheres namely atmosphere, lithosphere, hydrosphere, biosphere and magnetosphere.

You have studied about them in earlier classes.

Out of these, atmosphere is the one which is actually related with climate and weather.

The climate of any region is decided by detailed study and observation for longer period of time such as 30 years.

These observations give us an idea about the trends in the weather and its elements.

Multiple occurrences of any phenomena of weather with consistency help us to decide the climate of the region.

The climate of a place is responsible for the variety in so many factors including our food, our occupations, our houses, our clothes and many activities.

Teacher's Note

Climate decides why people in Kerala eat rice and fish while people in Rajasthan eat wheat and eat less fish. This is because different places have different climates.

Exam Trick

Remember: Climate = 30 years of weather data. Weather = today's temperature. Just like your marks depend on many exams, climate depends on many years of weather.

Points to Remember

Climate is studied for at least 30 years.
Weather and climate are different things.
Atmosphere controls the climate of a place.
Climate affects food, clothes, houses and all human activities.

Can You Tell?

Make a list of the human activities you think that are not influenced by climatic elements.

Let us see how far you can proceed.

Geographical Explanation

Climate directly or indirectly influence not only our physiology but all human activities.

Climate has enormous influence on the pedological processes.

Climate and soils in a region determine the land cover condition of the region.

Its effect on the vegetal growth in the region is obvious.

Agriculture, that determines the food habits of the population in a region, is greatly influenced by the climate.

Teacher's Note

In India, farmers grow rice in rainy areas like Kerala because the climate is wet. In Rajasthan, farmers grow wheat because the climate is dry. This shows how climate affects agriculture.

Exam Trick

Remember: Climate = soil + plants + animals + human life. All things in one place depend on climate.

Points to Remember

Climate affects agriculture and food habits.
Climate influences soils in a region.
Climate determines what plants and animals live in an area.
Different climates have different types of vegetation.

Classification Of Climate And Identifying Climatic Regions (Natural Regions)

During the second half of the 19th century and early 20th century, when geographers debated the concept of region and regionalization, climate got primacy over any other criteria for defining the macro regions of the world.

There have been many attempts to define macroregions of the world on the basis of climatic conditions.

We will divide these regions on the basis of latitudinal locations.

Let us look at each region in detail.

Refer to the given map in fig. 4.1 simultaneously.

Locate the places on the map.

You are advised to use an atlas too.

Find Out!

Use Internet or reference books to find out about the attempts at classification of climates.

Do You Know?

Why do we call the Climatic Regions also as Natural Regions?

A natural region is a basic geographic unit. Usually it is a region which is distinguished by its common natural features of geography, geology, and climate.

From the ecological point of view, the naturally occurring flora and fauna of the region are likely to be influenced by its geographical and geological factors, such as soil and water availability, in a significant manner.

Thus most natural regions are homogeneous ecosystems.

Teacher's Note

A natural region has its own weather, soil, plants and animals all mixed together. For example, the Amazon Rainforest is a natural region where everything is wet and has tall trees.

Exam Trick

Remember: Natural Region = Climate + Soil + Plants + Animals all together in one place. It is like one big family living together.

Points to Remember

A natural region has common natural features.
Climate, soil and water are important in natural regions.
Flora and fauna depend on geographical factors.
Most natural regions are homogeneous ecosystems.
Natural regions are also called climatic regions.

A) Low-Latitude Regions: 1) Equatorial Rainforests

Can You Tell?

Read the graphs fig. 4.2 a) and b) and answer the following questions.

Locate the places on the map:

1) In which months there is no rainfall?

2) In which month is the temperature highest?

3) In which month is the temperature lowest?

4) What could be the factors which influence the climate of these places?

5) Write a concluding statement about the climate of both the places based on the questions above.

Geographical Explanation

Temperatures are almost the same throughout the year in this region.

As this region is located within 5° to 10° of the equator, the noon rays of the Sun are always close to being directly overhead.

Days and nights are almost of equal length and amount of insolation remains nearly constant throughout the year.

In other words, the concept of summer and winter as being hot and cold seasons do not exist in these parts.

The ITCZ (Inter-Tropical Convergence Zone) is an area of low pressure in equatorial regions.

This is where the northeast and southeast Trade winds converge.

They move north or south with the apparent movement of the Sun.

Heavy precipitation is associated with warm, humid air of the doldrums, the unstable conditions along the ITCZ and the low pressure areas.

Due to convectional currents, moist air rises, condenses and results in heavy rain almost daily.

Although no season can be called dry, during some months it may rain only for 15 or 20 days.

Teacher's Note

In equatorial regions like Congo, it rains almost every day but it is very hot. The temperature never changes much from hot. People there wear light clothes and live in simple houses to stay cool.

Exam Trick

Remember: Equatorial = Always hot and wet. Like a hot bathroom with steam. No winter, no summer, just hot and wet all the time.

Points to Remember

Equatorial regions are between 0° to 10° latitude.
Temperature is always around 27° C throughout the year.
Rainfall is very heavy and happens almost every day.
There is no dry season in equatorial regions.
ITCZ causes heavy rain in these areas.

Use Your Brain Power!

1) What would be the annual range of temperature in this region?

2) Where is this type of climate found in India?

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