- Introduction
- Rest time! Have fun
- Physics
- Chemistry
- BIOLOGY
- Reaching the age of Adolescence
- CROP PRODUCTION AND MANAGMENT
- Cells : The basic structural unit of life
- Nutrition in human beigns
- RESPIRATION IN HUMAN BEIGNS
- TRANSPORTATION IN HUMAN BEIGNS
- excretory system in human beigns
- NERVOUS SYSTEM
- PHOTOSYNTHESIS
- Respiration in plants
- REPRODUCTION IN PLANTS
- MOVEMENTS IN PLANTS
- Forest our lifeline
- WASTE WATER STORY
- WEATHER,CLIMATE AND ITS ADAPTATION .
- Reaching the age of Adolescence
- Model tests
- Animation time
water
WATER DAY
22 March is celebrated as the world water day!
Water is essential for all living begins .
SOURCES OF WATER
71% of the earth’s surface is covered with water. Almost all the water on the earth is contained in the seas and oceans, rivers, lakes, ice caps, as groundwater and in the atmosphere .
Forms of water
when water circulates through the water cycle it can be found in all the three forms,
1.Solid
2.Liquid
3.Gas
Solids
The solid form, snow an dice, is present as ice caps at the poles of the earth, snow-covered mountains and glaciers.
They cannot be compressed .
Liquids
Liquid water is present in oceans, lakes, rivers, and even underground.
They can be compressed to some extent .
Gases
The gaseous form is the water vapour present in the air around us.
They are highly compressible .
Water table
When we dig a hole in the ground near a water body we may find that the soil is moist. The moisture in the soil indicates the presence of water underground. If we dig deeper and deeper, we would reach a level where all the space between particles of soil and gaps between rocks are filled with water The upper limit of this layer is called the water table. nThe water table varies from place to place, and it may even change at a given place.
Ground water
The water table may beat a depth of less than a metre or maybe several metres below the ground.
The water found below the water table is called groundwater.
Infiltration
The process of seeping of water into the ground is called Infiltration .
The ground water gets recharged by this process
Aquifer
Places where ground water is stored between the layers of hard rock below water table is known as Aquifer .
Depletion of water table
Water drawn from under the ground gets replenished by seepage of rainwater. The water table does not get affected as long as we draw as much water as is replenished by natural processes. However, water table may go down if the water is not sufficiently replenished. This may happen due to many reasons. Increase in population, industrial and agricultural activities are some common factors affecting water table. Scanty rainfall is another factor that may deplete the water table. Yet another factor affecting water table could be deforestation and decrease in the effective area for seepage of water.
Increase in population
Increasing population creates demand for construction of houses, shops, offices, roads and pavements. This decreases the open areas like parks, and playgrounds. This, in turn, decreases the seepage of rainwater into the ground. What could be the consequence? Recall that a pukka floor does not allow water to seep in easily, while in a grass lawn water seeps through in no time. Moreover a huge amount of water is required for construction work. Often groundwater is used for this purpose. So, on the one hand we are consuming more groundwater, and on the other we are allowing lesser water to seep into the ground. This results in depletion of water table. In fact, the water table in some parts of many cities has gone down to alarmingly low levels.
Increasing industries
Water is used by all the industries. Almost everything that we use needs water somewhere in its production process. The number of industries is increasing continuously. Water used by most of the industries is drawn from the ground
22 March is celebrated as the world water day!
Water is essential for all living begins .
SOURCES OF WATER
71% of the earth’s surface is covered with water. Almost all the water on the earth is contained in the seas and oceans, rivers, lakes, ice caps, as groundwater and in the atmosphere .
Forms of water
when water circulates through the water cycle it can be found in all the three forms,
1.Solid
2.Liquid
3.Gas
Solids
The solid form, snow an dice, is present as ice caps at the poles of the earth, snow-covered mountains and glaciers.
They cannot be compressed .
Liquids
Liquid water is present in oceans, lakes, rivers, and even underground.
They can be compressed to some extent .
Gases
The gaseous form is the water vapour present in the air around us.
They are highly compressible .
Water table
When we dig a hole in the ground near a water body we may find that the soil is moist. The moisture in the soil indicates the presence of water underground. If we dig deeper and deeper, we would reach a level where all the space between particles of soil and gaps between rocks are filled with water The upper limit of this layer is called the water table. nThe water table varies from place to place, and it may even change at a given place.
Ground water
The water table may beat a depth of less than a metre or maybe several metres below the ground.
The water found below the water table is called groundwater.
Infiltration
The process of seeping of water into the ground is called Infiltration .
The ground water gets recharged by this process
Aquifer
Places where ground water is stored between the layers of hard rock below water table is known as Aquifer .
Depletion of water table
Water drawn from under the ground gets replenished by seepage of rainwater. The water table does not get affected as long as we draw as much water as is replenished by natural processes. However, water table may go down if the water is not sufficiently replenished. This may happen due to many reasons. Increase in population, industrial and agricultural activities are some common factors affecting water table. Scanty rainfall is another factor that may deplete the water table. Yet another factor affecting water table could be deforestation and decrease in the effective area for seepage of water.
Increase in population
Increasing population creates demand for construction of houses, shops, offices, roads and pavements. This decreases the open areas like parks, and playgrounds. This, in turn, decreases the seepage of rainwater into the ground. What could be the consequence? Recall that a pukka floor does not allow water to seep in easily, while in a grass lawn water seeps through in no time. Moreover a huge amount of water is required for construction work. Often groundwater is used for this purpose. So, on the one hand we are consuming more groundwater, and on the other we are allowing lesser water to seep into the ground. This results in depletion of water table. In fact, the water table in some parts of many cities has gone down to alarmingly low levels.
Increasing industries
Water is used by all the industries. Almost everything that we use needs water somewhere in its production process. The number of industries is increasing continuously. Water used by most of the industries is drawn from the ground