Drainage System Class 11 Geography Competency Based Questions and Answers

 Drainage System

Question: What is drainage, and what is a drainage system?

Answer:

• Drainage: Flow of water through a well-defined channel.
• Drainage system: The network created by all channels of drainage.

Question: Important Drainage Pattern

Answer:

There are mainly four types of drainage patterns:

1. Dendritic pattern: The branches of tree-like drainage patterns are known as the dendritic pattern of drainage. These are mainly found in the rivers of the northern Indian plain.
2. Radial Pattern: This type of drainage pattern generally forms when many rivers originate from the same mountain peak and flow in different directions. The rivers formed this type of drainage pattern in the Amarkantak range.
3. Centripetal pattern: This pattern forms when many rivers discharge their water in a same lake or any other water bodies.
4. Trellis pattern: When the main or primary tributaries are parallel to each other and secondary tributaries join the main tributaries in right angle.

Question: Differentiate between a river basin and a catchment area.

Answer: 

The drainage basin and catchment area are both are the areas from where the river gets water. But there are a few differences between these two concepts. These are as follows:

Catchment area	Basin area
A catchment is a specific area from which rain or snowfall water flows into a river, stream or a reservoir.	A river basin is the large area of a whole river system from which the water drains into the river.
The catchment area is small.	The basic area is large.
A catchment is a small unit of a large river basin area.	A river basin area is a large unit that may be a combination of multiple catchments or watersheds.
This concept is mainly used for dam construction, reservoir planning, or watershed management.	This concept is mainly used for studying the whole geographical aspect of that particular area.

Question: Differentiate between the Arabian Sea drainage and the Bay of Bengal drainage.

Answer:

The whole peninsular drainage system is mainly divided into two categories based on the orientation of the landmass and the water discharge into the sea. These are the Arabian Sea drainage and the Bay of Bengal drainage. These two river system is mainly separated by the water divide, namely the Delhi ridge, the Aravalli, and the Sahyadris. The remarkable differences between these two river systems are as follows:

The Arabian Sea drainage	The Bay of Bengal Sea drainage
Rivers drain their water to the Arabian Sea.	Rivers drain their water to the Bay of Bengal.
These rivers are shorter in length.	These rivers are longer in length.
This river system cover very small area of the Indian river system.	This river system cover large area of the Indian river system.
The basin areas of these rivers are very small except for the Narmada and the Tapi.	The basin areas of these rivers are very large, like the basin area of the Godavari, Krishan.
The Narmada, Tapi, Sabarmati, Mahi, Luni, etc., are the main rivers.	The Ganga, Brahmaputra, Mahanadi, Godavari, Krishna, Kaveri, etc., are the main rivers.
These rivers are mostly non-perennial, except the Narmada and the Tapi.	The Himalayan rivers are perennial, and the peninsular rivers are seasonal.
These rivers carry very less sediments, and therefore, these are not favourable for delta formation.	These rivers carry more sediments, and therefore, these are favourable for delta formation.
The coastal plain formed by the Arabian Sea drainage is narrow.	The coastal plain formed by the Bay of Bengal drainage is wide.

Question: Differentiate between the Himalayan drainage and the peninsular drainage.

Answer:

Based on origin, nature and characteristics of the Indian rivers, these are broadly categorised into two categories - The Himalayan drainage and the Peninsular drainage. The differences between these two river systems are as follows:

The Himalayan drainage	The Peninsular drainage
These rivers mainly originate from the mountain peaks of the Himalayas.	These rivers originate from the Indian peninsular hills or mountains.
These rivers are fed by the water of rainfall as well as by the melting of ice.	These rivers are mainly fed by rainwater.
All the Himalayan rivers are longer in length.	These rivers are comparatively shorter in length.
These rivers have many long tributaries.	These rivers have fewer and shorter tributaries.
The Himalayan rivers formed large deltas.	Peninsular drainage formed deltas on the eastern coast and estuaries in the west.
These rivers formed meanders in the plain.	These rivers formed fewer menaders.
The Himalayan rivers are young and active.	These rivers are very old and mature.
The Ganga, Brahmaputra, and Indus are the main rivers.	The Mahanadi, Godavari, Krishna, Kaveri, Narmada, and Tapi are the main rivers.

Question: Why is the Kosi River known as the 'sorrow of Bihar'?

Answer:

The Kosi River is known as the 'sorrow of Bihar' due to some of its notorious characteristics. These are as follows: 

1. Frequent flood:

The Kosi River carries a large volume of water due to huge rainfall in the Himalayan region, especially in the monsoon season. As a result, frequent flood is common in the Kosi River basin area.

2. Huge sediment deposition:

The Kosi River carries a huge amount of sediments from the Himalayan region, and therefore, the speed of the river water decreases, and the river bed rises.

3. Channel shifting:

Due to huge siltation on the river bed, sometimes the river beds blocked by this huge sediment and therefore, the river changes its course frequently, which causes huge damage.

4. Crops and properties destruction:

Due to floods, course shifting, crops or property destruction, life loss becomes more common in this river basin area.

5. Human suffering:

Due to these types of notorious characteristics of the Kosi River, many people suffer every year, especially when it becomes very difficult for the farmers and rural communities to lead a normal life every year.

Question: What is the "Namami Gange Programme"? Explain its main objectives and main pillars of the programme.

Answer:

'Namami Gange Programme is an integrated conservation programme initiated by the Union Government in June 2014. The main twin objectives of this programme were (i) to reduce pollution and conserve the river Ganga, and (ii) to rejuvenate the river Ganga.

The main pillars of the programme:

1. The construction of sewage treatment infrastructure focusing on major cities near the Ganga River.
2. Riverfront development through the construction of ghats, beautification of riverbank areas, etc.
3. River-surface cleaning of the plastics or any other garbage.
4. Afforestation in the riverbank side area and reducing the soil erosion on both sides of the River.
5. Public awareness through campaigning, community participation, promoting cleanliness drives, etc.
6. Ganga-Gram initiatives by making Ganga-Gram near the Ganga Riverbank area to enhance the participation and make the programme a grand success.

NCERT book's Competency-Based Question

Question: "Suppose you are travelling from Haridwar to Siliguri along the Foothills of the Himalayas. Name the important rivers or tributaries you will come across. Describe the characteristics of any one of them."

Answer:

While someone travelling from Haridwar to Siliguri along the foothills of the Himalayas, he/she will come across the following rivers and tributaries: The Ganga River and its tributaries like The Ramganga River, Kali River, Ghaghara River, The Gandak River, The Kosi River and the Teesta River, tributaries of the Brahmaputra. 

Characteristics of the Kosi River: 

Add the answer of the Kosi River mentioned above.

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