Students can Download Chapter 16 Water: A Precious Resource Questions and Answers, Notes Pdf, KSEEB Solutions for Class 7 Science, Karnataka State Board Solutions help you to revise complete Syllabus and score more marks in your examinations.
Karnataka State Syllabus Class 7 Science Chapter 16 Water: A Precious Resource
Class 7 Science Water: A Precious Resource NCERT Textbook Questions and Answers
Question 1.
Mark ‘T’ if the statement is true and T’ if it is false:
(a) The freshwater stored in the ground is much more than that present in the rivers and lakes of the world. (T/F)
Answer:
True
(b) Water shortage is a problem faced only by people living in rural areas. (T/F)
Answer:
False
(c) Water from rivers is the only source for irrigation in the fields. (T/F)
Answer:
False
(d) Rain is the ultimate source of water. (T/F)
Answer:
True
Question 2.
Explain how groundwater is recharged?
Answer:
Rainwater and water from other sources such as rivers and ponds seeps through the soil and fills the empty spaces and cracks deep below the ground. This process is called infiltration. Then the groundwater is stored between layers of hard rock below the water table. This is known as an aquifer. Thus, the groundwater gets recharged by this process.
Question 3.
There are ten tubewells in a lane of fifty houses. What could be the long term impact on the water table?
Answer:
If the people of the fifty houses use the ten tube wells, then the water required by them is drawn from the ground. If these tube wells are used for a long time, then the groundwater would be reduced and the water table would go down.
Question 4.
You have been asked to maintain a garden. How will you minimise the use of water?
Answer:
To maintain a garden, water is necessary. Therefore to minimize the use of water, we can apply the drip irrigation method. In this method, water is supplied directly to the base of the plants using narrow pipes, thereby reducing the loss of water and also minimise the use of water.
Question 5.
Explain the factors responsible for the depletion of the water table.
Answer:
The following factors are responsible for the depletion of the water table :
1. Increasing population – as a result of the increasing population, all the facilities such as houses, shops, roads, offices, pavements, etc increase to fulfill the increasing demands. This, in turn decreases the open area for seepage of water into the ground.
2. Industrialization – Most of the stages of manufacturing processes in industries require water. If the number of industries increases, then the water required by them will also increase. Therefore, increase of industries contributes to the depletion of the water table.
3. Agricultural activities – India is an agricultural country and agriculture is impossible without water. The water for agriculture is mainly utilized from groundwater, rainwater and canal water. As there is no rainfall in many places, agriculture cannot be entirely dependent on rainwater. Also, canal water is available in a few places only. Therefore, groundwater is the main source of water for agricultural activities and this causes depletion of water table.
Question 6.
Fill in the blanks with the appropriate answers:
(a) People obtain groundwater through Wells and tubewells.
(b) Three forms of water are solid, liquid and gas.
(c) The water bearing layer of the earth is Water table.
(d) The process of water seepage into the ground is called infiltration.
Question 7.
Which one of the following is not responsible for water shortage?
(i) Rapid growth of industries
(ii) Increasing population
(iii) Heavy rainfall
(iv) Mismanagement of water resources
Answer:
(iii) Heavy rainfall.
Question 8.
Choose the correct option. The total water
(i) in the lakes and rivers of the world remains constant.
(ii) under the ground remains constant.
(iii) in the seas and oceans of the world remains constant.
(iv) of the world remains constant.
Answer:
(iv) of the world remains constant.
Question 9.
Make a sketch showing groundwater and water table. Label it.
Answer:
Class 7 Science Water: A Precious Resource Additional Important Questions and Answers
Question 1.
Which are the Sources of Water on Earth?
Answer:
Almost all the Water on the Earth is contained in the seas, Oceans, rivers, lakes, ice caps, groundwater and in the atmosphere.
Question 2.
When is world water day is celebrated? What is its importance?
Answer:
Every year 22 March is celebrated as the world water day to attract the attention of ev¬erybody towards the importance of conserving Water.
Question 3.
What is the meaning of “Jalhai to Kalhai”
Answer:
The meaning of the slogan is if you have water, you can think of the future. There can be no life without it.
Question 4.
Define fresh water.
Answer:
The water which is fit for human consumption is called freshwater.
Question 5.
Which year is celebrated as “International year of freshwater”
Answer:
The year 2003 was observed as the International year of freshwater to make the people about the scarcity of freshwater.
Question 6.
Define the Water cycle and draw a neat diagram and table the parts.
Answer:
The earth has been maintained for millions of years by various processes which make the
water cycle.
The continuous cycling of water among its three forms keeps the total amount of water on the earth constant even when the whole world is using it.
Question 7.
Define an aquifer.
Answer:
The places where the groundwater is stored between layers of hard rock below the water table is known as an aquifer.
Question 8.
What is infiltration?
Answer:
The process of seeping water into the ground is called infiltration.
Question 9.
Define the water table and groundwater. Write a neat diagram to show both.
Answer:
The upper level of the groundwater layer is called the water – table. The Water found below the water – table is groundwater.
Question 10.
What is the source of groundwater?
Answer:
The rainwater is the main source of groundwater. Water from other sources such as riv¬ers, ponds seeps through the soil and fills the empty spaces and cracks deep below the ground.
Question 11.
What is Water – shortage?
Answer:
Because of various reasons the water shortage has become a matter of concern throughout the world. It is estimated that in a few years from now more than 1/3 of the people in the world could face water scarcity.
Question 12.
Define rainwater harvesting.
Answer:
The rainwater can be used to recharge the groundwater is known as rainwater harvesting. The rainfall is the main source of water, so we should not waste the rainwater.
Question 13.
Drip irrigation is necessary. Why?
Answer:
A former using water in the field can also use water economically by this method. It is a technique of watering plants by making use of narrow tubings which deliver water directly at the base of the plant.
Question 14.
How the Scarcity of water in Rajasthan could be solved?
Answer:
Rajasthan is a hot and dry place. The challenge of natural scarcity of water was solved by a band of social workers. They transformed a dry area in the Alwar district into a green place. They have revived five dried – up rivers by constructing water harvesting structures.
Question 15.
What will be the effect of the plant, if it is not watered for a few days?
Answer:
The plant will die, without water, no living organisms can survive. So water is very much essential for all living things.