Answer: Option A. ->
:

Definition: 1 Mark
Methods: 2 Marks
Water conservation is a process of preventing wastage of water, using water carefully and recharging groundwater.
Water conservation can be done by:

1) Repairing leaking pipes and taps.
2) Not wasting water during brushing teeth, shaving, bathing, washing clothes and during other activities.
3) Rainwater harvesting.
4) By drip irrigation of plants.

Answer: Option A. ->
:

Reasoning: 2 Marks
Alternative ways: 1 Mark
Installing hand pumps and deep boring pipes in an area where there is water scarcity is not a good practice. Groundwater is a major source of fresh water for human beings. It is true that groundwater gets recharged through infiltration but the process of infiltration is very slow and if the rate of consumption of groundwater is greater than the rate of infiltration then groundwater will be deplete eventually. So people should use groundwater judiciously. Otherwise, the water table would go down and ultimately we will run out of groundwater.
Other ways in which we can ensure enough water supply are:
i) Rainwater Harvesting - It is a method of collection and storage of rainwater for domestic or agricultural use later. This reduces our dependence on groundwater.  
ii) Bawris are big tanks with steps going down are constructed to store rainwater for a longer time as the amount of water evaporated will be less.

Answer: Option A. ->
:
Each method: 0.5 Mark
The various methods that we can use to prevent groundwater depletion are: 
i) Build Bawris to store rainwater.
ii) Turn off taps while brushing.
ii) Mop the floor instead of washing it.
iv) Use drip irrigation instead of tube wells for agricultural practices.
v) Practice rainwater harvesting.
vi) The roots of a plant hold the soil firmly and prevent soil erosion. The roots of plant absorb and store water in them.

Answer: Option A. ->
:

Statement: 1 Mark
Explanation: 2 Marks
Evaporation is a time taking process and does not happen within seconds.
The water that falls on the ground seeps through the pores on the ground and goes below to form a part of the groundwater.
This process is called infiltration. Even the rainwater that falls on the ground recharges the groundwater through this process.
Some water seeps even below and forms a part of aquifers.

Answer: Option A. ->
:

Effect on Plants: 1.5 Marks
Effect on humans: 1.5 Marks
Plants need water to get nutrients from the soil to prepare their food. So, if water is not present in a proper amount in the soil, plants will not be able to get nutrients.
If plants do not get proper nutrition ultimately they will die.
This will have a catastrophic effect on humans. Without plants, there will be no oxygen, and no food, both of which are essential for the survival of humans. 
These are essential elements for living. Without them, we will die. So, it is necessary for us to ensure that plants get enough water.

Answer: Option A. ->
:
Name and explanation: 1 Mark each
The major sources of water pollution are:
1) Increasing Population
2) Increasing Industries
3) Agricultural activities
Increasing Population: Increasing population creates demands 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.
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.
Agricultural Activities: Farmers have to use groundwater for irrigation. Population pressure on agriculture forces more usage of groundwater day by day. This results in depletion of water table.

Answer: Option A. ->
:

Explanation: 3 Marks
Diagram: 2 Marks
Water cycle is a natural cycle by which water flows across the globe, both above and below the ground. The mass of water on earth remains constant but keeps flowing from one form to another. Starting from the ocean and seas, water gets evaporated and reaches the atmosphere. There, it cools down and forms clouds. These clouds are responsible for precipitation. Rivers, ponds and surface water is derived mainly from rainwater. Rivers also get water from glaciers and snow caps. Rainwater also recharges the groundwater through infiltration. The water then travels back to the seas and oceans either through the rivers (above the ground) or through groundwater runoff (below the ground). Thus, the cycle gets completed and water keeps flowing continuously. A diagram depicting  this cycle is given below,

Answer: Option A. ->
:

Each Point: 1 Mark
(i) Evaporation is a slow process by which water gets converted from the liquid state to the gaseous state. In water cycle, evaporation is an important process for the formation of water vapours. So, "Evaporation” matches with "Generation of water vapour”.

(ii) Infiltration is the process by which groundwater gets recharged, so it matches with "Recharging of groundwater”.

(iii) Condensation is the process by which water gets converted from gaseous state to liquid state. In the water cycle, condensation is responsible for the formation of clouds. So, it matches with "Formation of clouds”.

(iv) Drip irrigation is a method for conservation of water. So, it matches with it in column 2.

(v) Precipitation is responsible for the transfer of water from clouds to the ground. So, it matches with "transfer of water from the atmosphere".

Answer: Option A. ->
:

Explanation of each activity: 1 Mark
Agricultural activities use a lot of water and irrigation by traditional methods leads to wastage of water. Also, use of rainwater for irrigation interferes with the process of infiltration which recharges the groundwater.

Deforestation or cutting of trees also hampers the process of infiltration as trees hold rainwater and allow ample time for seeping of water droplets under the ground. In the absence of trees, the rainwater gets washed off easily and cannot be absorbed by the ground.

Industrial work and factories also use a lot of water and consuming it from the river will decrease the level of water which may lead to drying of the river.

Increase in population creates demand for more water and more construction, which leads to more consumption of water.
Again, construction work consumes a lot of water and blocks pores in the ground from absorbing water.
So, we see that all these activities would lead to further depletion of water and will decrease the water table.

Answer: Option A. -> True
:
A

Excessive irrigation is a loss in two ways, firstly it might damage the entire crop and secondly, it causes wastage of precious freshwater which just flows away.