7th std lesson ppt

2. Water Footprint
A waterfootprint is an important footprint that a person
leaves on the environment . It is the amount of water
used during the day in the house , at school , as well as in
the food eaten by that person.
Water
footprint
Heavy
footprints
Light
footprints

3. Sources Of Water
 Natural resource
 Renewable
 Cannot live without
 3-quarter of earth’s surface

4. Most water in seas and oceans
is
so
Small fraction available
Salty
so
Use carefully
Ground water
Groundwater is the water found
underground in the cracks and spaces
in soil,sand and rocks.
Aquifers
The spaces with water in the
underground rocks are known as
Aquifers.
Surface water
Surface water is naturally occuring
water on the earth’s surface,ponds
lakes,rivers, and streams.

6. States Of Water
Wate
r
Liquid state
#Calledwater
#0’c-100’c
#Rain,waterbodies
Gaseous
state
#Intheairaswatervapour
#Occursanytime

7. Water Cycle
 Known as Hydrological cycle.
 The water cycle describes how Earth’s water is not only
always changing states between liquid(rain),solid(ice),and
gas (vapour),but also moving on,above,and inside earth.
Evoparation
Transpiration
CondensationPrecipitation
Percolation

9. Availablity of Water In India
Indiaisavastcountryandthe
rainfall isnotthesameeverywhere.
Someregionshaveexcessiverains
whilesomeothershaveverylittle
rainfall. Excessive rainscause
floods,whereastheabsenceof
rainsresultsindroughts.Therefore,
someregionsinourcountrymay
havefloodswhileothersmaysuffer
fromdroughtsatthesametime.

10. Uses of Water
Domestic use
Water is not only used for drinking or cooking food, It is used in so
many works such as washing clothes, need for plant, bathing and
used in many experiments as an agent.
In a house, water is needed for carrying out various activities.
The system of drawing water from treatment plant and making it
available at all appliances (fixtures) for use is known as domestic
water supply system.

12. Commercial and Industrial use
Commercial and Industrial Uses of Water. Besides being
vital for human survival, water is also necessary in
commerce and in industry.
Agricultural Use
Agricultural water is used for irrigation, pesticide and
fertilizer applications , crop cooling (for example,
light irrigation), and frost control.

14. Industrial Agricultural Domestic
Use use use

15. WaterDepletion-Groundwater
Groundwater
depletion, a term
often defined as
long-term water-level
declines caused by
sustained groundwat
er pumping, is a key
issue associated
with groundwater
use.

16. Reasons for Groundwater Depletion
Increasing population
Careless and excessive usage
Increasing
industrialization/commercializati
on
Erratic monsoons
Deforestation
Non-biodegradable waste matter

17. Conservation of Water
• Educatingourpopulation
• Recyclingof water
• Treatingsewageandfactorywaste
• Buildingdamsandreservoirs
• Buildingcheckdams
• Betterwaysof irrigation
• Plantationoftrees
• Encouragingrainwaterharvesting

18. Checkdam Dripirrigation

20. Plants Without Water?
Plants need nutrients from the soil, water, and light from
the sun to grow and stay alive. If plants did not
get water, they would die.

21. -Done by MAANVI.S
7 a5