Water: A Precious Resource
Class 7th Science CBSE Solution
- Mark T if the statement is true and F if it is false: a. The freshwater stored in the…
- Explain how groundwater is recharged?
- There are ten tube wells in a lane of fifty houses. What could be the long-term impact on…
- You have been asked to maintain a garden. How will you minimize the use of water?…
- Explain the factors responsible for the depletion of water table.…
- Fill in the blanks with the appropriate answers: a. People obtain groundwater through…
- Which one of the following is not responsible for water shortage? i. Rapid growth of…
- Choose the correct option. The total water i. in the lakes and rivers of the world remains…
- Make a sketch showing Ground water and Water Table. Label it.
Exercise
Question 1.Mark ‘T’ if the statement is true and ‘F’ 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)
b. Water shortage is a problem faced only by people living in rural areas. (T/F)
c. Water from rivers is the only source for irrigation in the fields. (T/F)
d. Rain is the ultimate source of water. (T/F)
Answer:
a. T
The freshwater stored in the ground is much more than that the present in the rivers and the lakes of the world. Most of the water is present in the form of ice-caps, glaciers and rivers and is unfit for drinking. The water which is used mostly is ground fresh water and moreover, it is much more than that present in rivers and lakes.
b. F
This statement is not true. Water shortage is being faced in rural area as well as in urban areas also. This issue is very alarming. It has been arisen due to overpopulation and misuse of water resources also.
c. F
The only source for irrigation in the fields is not only water from rivers. The other sources are rainwater, underground water through tube-wells.
d. T.
Rain is the ultimate source of water because the water which is discharged into the ground comes from rain and the water in rivers, ponds is also maintained through rainwater.
Question 2.
Explain how groundwater is recharged?
Answer:
Groundwater is recharged through:
1. Rainwater
2. Rivers, Ponds, and other sources
The water from rain or rivers, ponds, etc. seeps through the soil and the empty space and cracks inside the ground are filled by this water. This process is known as Infiltration. The groundwater thus gets stored through the process of infiltrations.
Question 3.
There are ten tube wells in a lane of fifty houses. What could be the long-term impact on the water table?
Answer:
The long-term impacts of ten tube wells in a lane of fifty houses are as follows:
1. The water table gets depleted
2. Water table will fall below the pipe of tube well
3. Water can’t be fetched with the help of tube-wells anymore.
4. There will be shortage of water for the daily needs.
Question 4.
You have been asked to maintain a garden. How will you minimize the use of water?
Answer:
The use of water can be minimized by following steps:
1. Harvesting of rain water and using it for garden.
2. Reusing the water for garden, left after bathing and washing utensils ii. By using water after bath or washing utensils for watering the garden.
Question 5.
Explain the factors responsible for the depletion of water table.
Answer:
The factors which are responsible for the depletion of the water table are as follows:
1. Increasing-Population: Increase in population results in an increase in demand for water. The overpopulation leads to the construction of houses, roads, gardens and thus, in turn, decreases the open area for the seepage of water into the ground.
2. Industrialization: No doubt, industrialization has provided employment but it has also lead to a shortage of resources such as water. There is an increase in the utilization of water in industries. Thus leading to depletion of the water table.
3. Agricultural Activities:
India is an agricultural country and agriculture is generally done through the usage of groundwater during the period of no rainfall and therefore, causing the depletion of the water table.
Question 6.
Fill in the blanks with the appropriate answers:
a. People obtain groundwater through _____ and _____.
b. Three forms of water are _____,______ and _____.
c. The water bearing layer of the earth is ______.
d. The process of water seepage into the ground is called _______.
Answer:
a. Wells and hand pumps
The ground water which have come from rainwater and other sources, is obtained using the wells and hand-pumps.
b. Solid (ice), Liquid (water) and gas (water vapour)
Water is present in three forms: Solid which is in the form of ice, liquid , in form of water and gas i.e. in form of water vapor or steam.
c. aquifer
The layer which bears water inside the Earth is known as Aquifer.
d. infiltration.
The water from rain or rivers, ponds etc. seeps through the soil and the empty space and cracks inside the ground are filled by this water. This process is known as Infiltration. The ground water thus gets stored through the process of infiltrations.
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:
Heavy rainfall is not responsible for water shortage. Instead it is helpful in case when there is shortage of water or drought.
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:
The total water of the world remains constant.
About 71% of Earth is covered with water and water of the world remains constant.
Question 9.
Make a sketch showing Ground water and Water Table. Label it.
Answer:
The sketch showing ground water and water table along with labelling is as follows:
