Current Affairs 3rd Class

Category : 3rd Class

                                                               Environment

Environment

Our environment includes living things like plants and animals and non-living things like air, water, soil, sunlight, weather, seasons, etc. All these are the components of environment.

Air

Air is all around us. Air contains water in the form of water vapour. It also contains dust particles, gases like oxygen, hydrogen, carbon dioxide, etc.

Water

Water is very important for life on earth. Rivers, glaciers and lakes are sources of fresh water on earth. Seas and oceans contain salt water.

States of Water

Water occurs in all the three states. Ice is the solid form of water. When ice melts, it changes into liquid form. When water is heated or boiled, it becomes steam. Steam is also called water vapour.

Water Cycle

Water from rivers and ponds goes up as water vapour in day time, when it reaches a great height it forms clouds in the sky. The clouds cannot hold the water inside them.

This water falls back to earth as rain. The rain water runs back to fill the rivers and ponds. This is called water cycle.

Rocks

Our earth is made up of rocks. Rocks are of many kinds and are very useful to us. For example, rocks like marble, granite, sandstone, etc. are used to make buildings. Pebbles, which are the small pieces of rocks, are used in making roads, in railway tracks, etc.    

Some rocks, like diamond, ruby and emerald are used in jewelry.  

Soil

Rain wind and the sunlight are continuously breaking the rocks of earth into smaller and smaller pieces, until they cannot break any further. These very tiny pieces of rocks form the soil on earth.

Soils are of different types and different colures. This is because different types of soils contain different particles.

Soil also contains air and water? Water trapped in the soil is called moisture.

Soil is useful to us in many ways.

(i) Plants take water from the soil to grow.

(ii) In soil, we grow vegetables and build our homes, roads, schools, etc.

(iii) Soil is also home to many animals, such as earthworms, beetles, and snails.

(iv) We get many valuable minerals from soil. For example, iron, gold, silver, etc.

Weather

Changes in weather is due to sun, wind and water vapours in the air.

Sunny Days

Morning and evening are cooler because the sun rays are slanting. Noon time is the hottest part of the day.

Windy and Cloudy Days

When wind blows slowly, it is called as a breeze. Strong winds along with rain or shower is called storm. The sun appears to hide on cloudy days. It is cooler on windy and cloudy days, than on sunny days.

Seasons

Changes in weather after few months are called changing seasons. There are mainly four seasons namely summer, winter, autumn and spring. Summer is the hottest and winter is the coldest time of the year. Leaves fall in autumn. In spring, there are flowers everywhere.

Our environment consists of atmosphere, water bodies, oceans, forests, lands and mountains. All living beings live in this environment. It is our responsibility to keep our environment clean. Keeping environment clean helps us in living healthy and long life. 

Causes of Environment Pollution

(i) Cutting trees or deforestation is one of the reasons responsible for polluting the environment.

(ii) Burning fossil fuels such as petrol or diesel pollutes the environment.         

(iii) Throwing garbage here and there also pollutes the environment.

(iv) Using plastic bags cause serious health hazards.

(v) Disposing chemical wastes in the rivers, pollutes the water bodies and thus causes serious threat to the environment.