LIWA

India: Climate, Natural Vegetation, Forests and Wildlife

ICSE Class 8 · Geography · Chapter 10

What this chapter covers

Key definitions

Weather is the condition of the atmosphere at a particular place and time, such as how hot, wet, windy or cloudy it is today.

Climate is the average weather of a large area, worked out from records kept over about thirty years or more.

Latitude is the distance of a place north or south of the Equator, measured in degrees.

Altitude is the height of a place above sea level.

Relief is the shape and height of the land surface, including its mountains, plateaus and plains.

Air pressure is the weight of the air pressing down on the Earth's surface.

Western disturbances are weather systems that travel from the Mediterranean region across Iran and Pakistan in winter and bring light rain to north-west India and snow to the Himalayas.

Kharif crops are crops sown at the start of the south-west monsoon, in June and July, and harvested in autumn, such as rice, cotton and maize.

Rabi crops are crops sown after the monsoon, in October and November, and harvested in spring, such as wheat and mustard.

Natural vegetation is the plant life, such as forests, grasses and shrubs, that grows in an area on its own without being planted or looked after by people.

Thorny vegetation is the scattered vegetation of thorny trees and bushes that grows in regions receiving less than 70 cm of rain a year.

Coniferous trees are trees with needle-shaped leaves and cones, such as pine and fir, that stay green all year and can survive cold and snow.

Key points

Questions answered

How is climate different from weather?
Weather is the condition of the atmosphere at a place and time, and it can change within hours. Climate is the average weather of a large area worked out over about thirty years or more.
Why does Delhi have a continental climate while Mumbai has a maritime climate?
Mumbai is on the coast, and the slowly heating and cooling sea keeps its temperatures mild. Delhi is far inland, so it heats up strongly in summer and cools strongly in winter, giving a large annual range.
Give two ways in which the Himalayas affect the climate of India.
They block the cold winds from Central Asia in winter, keeping north India warmer. They stop the monsoon winds from passing northwards in summer, so the winds drop their rain over India.
Explain why the south-west monsoon winds blow towards India in summer.
In summer the land of north-west India becomes very hot and a low-pressure area forms over it. The Indian Ocean is cooler and has higher pressure. Wind blows from high to low pressure, so moist winds move from the ocean towards the land from the south-west.
Why does Chennai get most of its rain between October and December?
Chennai lies in the rain shadow for the south-west winds. Its rain comes from the retreating monsoon and north-east winds, which pick up moisture over the Bay of Bengal in October to December.
A place 2,000 m above sea level is near a coastal town where the temperature is 32 °C. Estimate the temperature at the higher place.
Fall = 2 × 6.5 °C = 13 °C. Temperature = 32 °C − 13 °C = 19 °C.
Give two ways in which the monsoon helps to unite the people of India.
Farmers across India follow the same kharif and rabi calendar set by the monsoon. Festivals such as Teej, Onam, Pongal and Bihu in different states all celebrate the rains or the harvest that follows them.
Why do trees of deciduous forests shed their leaves, and why do thorny plants have small leaves or thorns?
Deciduous trees shed their leaves in the dry season to reduce the loss of water. Thorny plants have small leaves or thorns for the same reason, because they grow where rain is very scarce.