lesson - 16 water ( POST 2 )

Good morning boys! In last class you learnt about the avaliability of fresh water on the Earth and the forms of water 
ANSWER THE FOLLOWING QUESTIONS TO CHECK YOUR PREVIOUS KNOWLEDGE-
1. How is water useful to the body ?
2.How much per cent  of fresh water is available on the Earth  for human consumption ?
LEARNING OUTCOMES OF THIS LESSON -
By end of this class you will be able to-
.draw and label the water cycle
.define the terms  water table ,ground water ,infiltration, aquifer. 

WATER CYCLE 
The continuous cycling of water in nature is called water cycle. Water keeps changing its form during the process of the water cycle


From the picture above ,it is clear that the process involved in the water cycle are- evaporation/ transpiration , condensation, precipitation.


 TRY THIS!.

a) In the diagram of  the water cycle given below,which words will you use in place of 1,2,3,4?
b) In which three forms does water exist in nature ?


WATER TABLE
Water table is the minimum depth  or the upper level   in the soil where all the pore spaces are filled with water. 
The water table varies from place to place and season to season.
The water found below the water table is called ground water.
HOTS!
1.Will the water table be higher in the rainy season or in the summer season ?                                    

2.Will the water table rise or fall when the groundwater pumped out is less than the water that seeps in ?

The main source of ground water is rain water and the water in rivers,ponds ,lakes etc
The ground water helps us in the following ways-
.it provides soil moisture for plant growth.
.it supplements water in streams,lakes,wells etc.
The process of seepage and percolation of surface water into the ground is called infiltration.
Huge reservoirs of water that gets collected between the layers of hard rocks below the water table are called aquifer. Water in the aquifer can be pumped out to the earths surface with help of tubewells, handpumps etc. 

HOME WORK

1. Read pages 257-258 of your reader.
EXERCISES TO BE DONE IN YOUR NOTEBOOK-
4. Define the terms given below -
a) Water cycle- Continous cycling of water in nature.
b) Water table- Minimum of depth in the soil where all the pore spaces are filled with water.
c) Aquifer - Huge reservoirs of water inside the earth.
d) Infiltration -The process of seepage and percolation of surface water into the ground.

5. Draw a well -labelled diagram of the water cycle.
ans: Please refer to the diagram of water cycle given above.

6. How does ground water help us?
ans : Ground water helps us in the following ways :
.it provides soil moisture for plant growth.
.it supplements water in streams,lakes,wells etc.