GSEB Class 9 Social Science Solutions Chapter 15 Drainage System

1. Write Short Answer for the Following Questions.

Question 1. Give difference: Himalayan rivers and Peninsular rivers.
Answer:
Himalayan Rivers
1. These rivers always contain water throughout the year.
2. They are long, deep, and have a slow flow.
3. They are often used as waterways.
4. Their river basin areas are quite large.
5. Meanders, which are winding bends, are often seen.
Peninsular Rivers
1. These rivers are seasonal, meaning they have water only at certain times of the year.
2. They are short, shallow, and have a fast flow.
3. They generally cannot be used as waterways.
4. Their river basin areas are relatively smaller.
5. Meanders are typically not seen in these rivers.
In simple words: Himalayan rivers are long, flow all year, and have big basins, while Peninsular rivers are shorter, flow seasonally, and have smaller basins.

Exam Tip: When comparing two types of geographical features, always use a point-by-point format to clearly highlight the differences and make your answer easy to understand for the examiner.

Question 2. Explain Drainage Pattern and Water Divide.
Answer:
1. The term 'drainage system' helps to describe the regular pattern of rivers in a region.
2. It can be seen that one main river, along with its smaller rivers or tributaries, comes from various directions and then joins together into a single river.
3. The water from these rivers flows into a reservoir, a sea, or a desert. So, when a river's water flows through its system in any specific area, that area is called a river basin.
4. When a mountain or elevated land separates the flow of water of two different river systems, it is then known as a 'water divide'.
In simple words: A drainage system is how rivers flow and connect. A water divide is high ground that separates water flowing in different directions.

Exam Tip: Define each term clearly and provide specific examples if possible to illustrate your understanding of the concepts.

Question 3. Explain the utility of lakes.
Answer: The utility of lakes is varied and important:
1. Lakes are used for navigation and for generating hydropower.
2. They assist in controlling the flow of a river, helping to prevent floods.
3. They also help to make the climate of the surrounding areas more moderate.
4. They are crucial for maintaining the aquatic ecosystem, supporting various forms of life.
5. Lakes help to boost tourism in a region.
6. They increase the natural beauty of an area and offer opportunities for recreation.
In simple words: Lakes are useful for travel, making electricity, controlling river flow, balancing weather, helping nature, and for fun activities like tourism.

Exam Tip: When listing utilities, try to categorize them (e.g., economic, environmental, social) to ensure a comprehensive answer.

Question 4. State the remedies to prevent water pollution.
Answer:
1. Water purification projects need to be put into action through programs like the National River Conservation Project.
2. Industrial units should clean harmful substances from the chemical waste they release into rivers.
3. Every citizen should be careful not to mix domestic waste into rivers.
4. Strong rules need to be made to stop industrial units from releasing their waste into rivers.
In simple words: To stop water pollution, we need clean-up projects, industries must filter their waste, people should not dump trash, and strict laws must be enforced.

Exam Tip: When discussing solutions to environmental problems, ensure your points cover different stakeholders like government, industries, and citizens.

Question 5. 'Godavari is named as Ganga of South'. Give reasons.
Answer: Godavari is called the 'Ganga of South' for several reasons:
1. It has the largest basin among all the peninsular rivers.
2. It begins from the slopes of the Western Ghats, near Nasik in Maharashtra.
3. It flows towards the east and joins the Bay of Bengal.
4. About 50% of its basin is located in Maharashtra, with the remaining part in Madhya Pradesh and Andhra Pradesh.
5. The total length of the Godavari is approximately 1465 km. Many smaller rivers, like Puma, Vardha, Pranhita, Manjara, Vainganga, and Penganga, meet the Godavari.
6. Godavari has a longer flow and a large basin, which gives it similar importance to the Ganga, hence its nickname.
In simple words: Godavari is called 'Ganga of South' because it's the biggest river in South India, flowing a long way with a large basin, and many other rivers join it.

Exam Tip: When explaining why something is named a certain way, provide both geographical and historical/cultural reasons if applicable.

2. Answer the Following.

Question 1. Explain the Ganga River System.
Answer: The Ganga River System is one of India's most significant river systems:
1. River Bhagirathi and Alaknanda emerge from the Gangotri area in the Himalayas and merge near Devprayag (Uttarakhand). From this point, the Ganga river leaves the mountains and enters the plains near Haridwar.
2. Many Himalayan rivers, such as Ghaghra, Gandak, and Kosi, later join the Ganga.
3. The Yamuna river begins from Yamnotri in the Himalayas, flows to the right side of the Ganga, and merges with the Ganga near Allahabad (Prayagraj).
4. The Ghaghra, Gandak, and Kosi rivers all originate in Nepal. Because of these rivers, the northern plain often experiences flood disasters every year.
5. India has been able to achieve agricultural prosperity thanks to the fertile plains formed by these rivers.
6. The Chambal and Betwa rivers originate in the peninsular plateau and meet the Yamuna. The Son river then joins the Ganga.
7. The combined flow of rivers from the north and south divides into two branches further downstream.
8. One branch goes into Bangladesh and is known there as Padma, while the other branch is called Bhagirathi-Hugli in West Bengal. These two branches eventually meet the Bay of Bengal.
9. The flow of the Ganga, known as Padma in Bangladesh, merges there with the Brahmaputra river, and their combined flow is then called 'Meghna'.
10. The Ganga-Brahmaputra delta is considered the most fertile delta in the world and is known as 'Sunderban'.
In simple words: The Ganga system starts when Bhagirathi and Alaknanda join, flowing from the Himalayas into plains. Many rivers like Yamuna, Ghaghra, and Kosi join it. It creates fertile lands but also causes floods. The river eventually splits into two, Padma and Bhagirathi-Hugli, meeting the Bay of Bengal, and forms the famous Sunderban delta.

Exam Tip: When explaining a river system, mention its origin, major tributaries, direction of flow, significant features (like deltas or flood plains), and its importance.

Question 2. Discuss the Narmada Basin.
Answer: The Narmada Basin is an important river system in central India:
1. The Narmada river begins near the Amarkantak plateau in Madhya Pradesh and flows westwards through a rift valley.
2. The Narmada Basin spreads across Madhya Pradesh and Gujarat.
3. The total length of the Narmada river is about 1312 km.
4. Its tributaries are not very long, and most of them meet the main river at right angles.
5. The Narmada river flows through a rocky terrain made of marbles. It flows faster because of the slope. The Dhuadhar falls are located here.
In simple words: The Narmada river starts in Madhya Pradesh, flows west, and covers parts of Madhya Pradesh and Gujarat. It's about 1312 km long, has short tributaries, and flows quickly through rocky areas, creating falls.

Exam Tip: For river basins, include details about origin, length, states covered, and any unique geographical features like waterfalls or rift valleys.

Question 3. Describe in detail Krishna and Kaveri basin.
Answer:
Krishna Basin:
1. The Krishna river starts from Mahabaleshwar in Maharashtra.
2. Its main tributaries include Tungabhadra, Koyna, Ghatprabha, Musi, and Bhima.
3. Its basin covers areas in Maharashtra, Karnataka, and Andhra Pradesh.
4. The total length of its tributaries is approximately 1400 km.
Kaveri Basin:
1. The Kaveri river has its origin in the Brahmagiri Range within the Western Ghats.
2. Amravati, Bhavani, Hemvati, and Kalini are its main tributaries.
3. Its basin spreads over Kerala, Karnataka, and Tamil Nadu.
4. The Kaveri river meets the Bay of Bengal to the south of Cuddalore in Tamil Nadu.
In simple words: The Krishna river starts in Maharashtra and flows through three states with many tributaries. The Kaveri river begins in the Western Ghats, has its own main tributaries, flows through three states, and reaches the Bay of Bengal.

Exam Tip: When describing multiple river basins, maintain a consistent structure (origin, tributaries, states, length/destination) for each to ensure clarity and completeness.

4. Find Out the Correct Option from the Given Options:

Question 1. Which lakes are formed due to meandering of rivers?
(a) Lagoon
(b) Ox-bow
(c) Oval-shape
(d) Square
Answer: (b) Ox-bow
In simple words: Ox-bow lakes are created when a river's bend gets cut off from the main flow.

Exam Tip: Remember that ox-bow lakes are a classic example of fluvial landforms resulting from river meanders and flood events.

Question 2. What is it called when a mountain or an upland separates the water flow of rivers from one another?
(a) Water formation
(b) Water divide
(c) River system
(d) Basin
Answer: (b) Water divide
In simple words: A water divide is a high area of land, like a mountain, that makes water flow in different directions.

Exam Tip: Understand the basic hydrological terms. A water divide is a geographical feature that separates drainage basins.

Question 3. Which of the following is not a peninsular river?
(a) Godavari
(b) Krishna
(c) Kosi
(d) Kaveri
Answer: (c) Kosi
In simple words: The Kosi river comes from the Himalayas, making it a Himalayan river, not a peninsular one like Godavari, Krishna, or Kaveri.

Exam Tip: Be familiar with the major Himalayan and Peninsular rivers to distinguish between them easily.

Question 4. Which of the following lakes is used for producing salt?
(a) Dhebar
(b) Sambhar
(c) Wuler
(d) Nal
Answer: (b) Sambhar
In simple words: Sambhar Lake is a saltwater lake in India, mainly used for salt production.

Exam Tip: Knowing the characteristics and uses of prominent geographical features like lakes can help answer such questions.

Question 5. Which are the main tributaries of Ganga?
(a) Yamuna, Ghaghra, Gandak and Kosi
(b) Yamuna, Chambal, Ghaghra and Kosi
(c) Yamuna, Ghaghra, Sharavati and Kosi
(d) Narmada, Ghaghra, Gandak and Kosi
Answer: (a) Yamuna, Ghaghra, Gandak and Kosi
In simple words: The Yamuna, Ghaghra, Gandak, and Kosi are all major rivers that join the Ganga.

Exam Tip: It is important to memorize the key tributaries of India's major rivers, especially the Ganga, as this is a common question type.

Gujarat Board Class 9 Social Science Drainage System Additional Important Questions and Answers

I. Answer the Following Questions.

Question 1. What do you mean by drainage system and drainage pattern? Name the types of drainage pattern found in Indian rivers.
Answer: The study of how rivers flow in a region is known as the drainage system. The natural arrangement of a river and its tributaries is called the drainage pattern. The drainage pattern of Indian rivers can be divided into four main types:
1. Dendritic drainage pattern
2. Trellis drainage pattern
3. Rectangular drainage pattern
4. Centrifugal/Radial pattern.
In simple words: A drainage system is how rivers flow, and a drainage pattern is the natural shape formed by a river and its smaller streams. India has four main types of drainage patterns.

Exam Tip: Clearly distinguish between 'drainage system' and 'drainage pattern' in your definitions, and list all types mentioned in the curriculum.

Question 2. Describe different drainage paterns.
Answer: The drainage patterns of Indian rivers can be divided into four parts:
(A) Dendritic Pattern: When a river and its tributaries form a shape similar to the branches of a tree, it is called a dendritic pattern. For instance, the Ganga river exhibits this pattern.
(B) Trellis Pattern: This pattern occurs when streams starting from a mountainous region meet one another, creating a net-like shape due to the slopes. This pattern is often seen where many streams of the Himalayan Mountains meet Himalayan rivers.
(C) Rectangular Pattern: A rectangular pattern is formed when the main river and its tributaries meet each other at right angles. Most rivers flowing through rift valleys, such as the Narmada, form this type of rectangular river system.
(D) Radial (Centrifugal) Pattern: In this drainage pattern, rivers flow outwards from a single central hilly region. A good example of a radial pattern is found in the rivers of Saurashtra.
In simple words: Rivers form different shapes: dendritic (like a tree), trellis (like a net in mountains), rectangular (meeting at right angles), or radial (flowing out from a central point).

Exam Tip: For each drainage pattern, provide a clear description and a relevant example to demonstrate your understanding.

Question 3. Explain the flow of a river in various sections (courses).
Answer: The flow of a river can be divided into three main sections, or 'Courses', each with distinct characteristics:
1. Upper Course
2. Middle Course
3. Lower Course.
(1) Upper Course:
1. When a river begins from a mountainous region, it flows quickly with a lot of energy, causing intense erosion.
2. The upper course carries a large amount of sand and sediments along with it.
(2) Middle Course: In the middle course, the river flows more slowly but spreads over wide areas. This course carries many sediments, which makes the river water appear muddy.
(a) Formation of meanders: The river's path, which began with a fall in the upper course, changes to a sideways movement. The river starts to move right, then left, creating bends or loops that resemble a horseshoe or an animal's hoof. These bends are called meanders.
(b) Formation of lakes: Sometimes, due to meanders and the impact of floods, a loop formed during meandering gets cut off from the main channel. This cut-off loop is known as an ox-bow lake.
(3) Lower Course:
1. The end of a river is called its mouth. The lower course refers to the final part of the river's journey.
2. In the lower course, the river has a high volume of water and discharges a large amount of sediments, even with a low energy level.
3. The river channel becomes deep and wide, and the surrounding landscape is flat.
(a) Formation of delta: At the mouth of a river, there is often a river delta. A delta is a large, muddy area where the river splits into many slow-flowing channels (distributaries). Deltas are highly fertile, triangular-shaped plains.
In simple words: A river's journey has three parts: the upper course is fast and erosive in mountains, the middle course slows down and forms bends (meanders) and ox-bow lakes, and the lower course is wide, flows slowly to the sea, and often forms fertile deltas.

Exam Tip: When describing river courses, link each course to specific landforms (e.g., erosion in upper, meanders in middle, deltas in lower) and explain the processes involved.

Question 4. What is river system? Name the major river systems of Himalayan rivers?
Answer: The large network of streams, lakes, and rivers that are part of a bigger river's network of tributaries and distributaries is collectively called the river system. In the Himalayan river system, there are three main river systems:
1. Sindhu River System
2. Brahmaputra River System
3. Ganga River System
In simple words: A river system includes all the connected streams, lakes, and rivers that flow into a main river. The main Himalayan river systems are Sindhu, Brahmaputra, and Ganga.

Exam Tip: Define the general term "river system" first, then list and briefly identify the major systems when prompted.

Question 5. Write a short note on Sindhu (Indus) River System.
Answer: The Sindhu (Indus) River System is one of the world's most significant rivers:
1. It is one of the longest rivers globally, with a total length of 2900 km.
2. The Sindhu river originates near the Mansarovar region in Tibet.
3. It has formed many deep, inaccessible ravines and passes.
4. About one-third of its basin is located in the mountainous region of Jammu and Kashmir.
5. First, the Sindhu flows north, then turns westwards, and enters India through Ladakh in Jammu and Kashmir.
6. Here, the Zaskar, Nubara, Shyok, and Hunza rivers meet the Sindhu.
7. From Jammu and Kashmir, the Sindhu river begins flowing towards Pakistan.
8. In Punjab, Pakistan, its main tributaries — Jhelum, Chenab, Ravi, Beas, and Satluj — meet the Sindhu at a place called Mithankot.
9. Then, the combined flow of all these rivers eventually flows southwards and joins the Arabian Sea.
10. These rivers move at a slower speed in the plains.
11. In 1960, a Treaty was signed with Pakistan regarding the distribution of the Sindhu river water.
12. According to this treaty, India can only use 20% of its water.
13. The waters of the Satluj, Ravi, and Beas rivers are used for irrigation in the states of Punjab, Haryana, and the south-western part of Rajasthan.
In simple words: The Sindhu river is a very long river starting in Tibet. It flows through parts of India and then through Pakistan, where many rivers join it before it reaches the Arabian Sea. A treaty limits India's water usage from it, with its waters mainly used for farming in certain Indian states.

Exam Tip: When writing a short note on a river system, include its origin, length, flow path, major tributaries, and any significant historical or political context (like the Indus Waters Treaty).

Question 6. What is delta region of Ganga called? Why did it get this name?
Answer:
- A large number of 'Sundari' trees grow in the delta region of the Ganga. For this reason, this region is called the Sundarban delta.
- It is also very famous for its mangrove forests, which thrive in brackish water.
In simple words: The Ganga delta is called Sundarban because many 'Sundari' trees grow there, and it's also known for its mangrove forests.

Exam Tip: Connect the name of the delta directly to its unique flora (Sundari trees) and the type of ecosystem (mangrove forests) that makes it distinct.

Question 7. Why are there many meanders on Ganga River System between Ambala and Sunderban delta?
Answer: There are many meanders on the Ganga River System between Ambala and the Sunderban delta due to several factors:
1. Ambala city acts as a water-divide between the Ganga and Sindhu rivers.
2. The distance from Ambala to Sunderban is about 1800 km, but the river has a very gentle slope in this stretch.
3. Ambala is located at an altitude of 300 meters above sea level, while Sunderban is at sea-level.
4. Considering this, the slope is approximately 6 km per one meter (1800/300 = 6). This means there is a very gradual drop in elevation.
5. Because of this gentle and continuous slope, the river flows slowly and forms many meanders.
In simple words: The Ganga river has many bends (meanders) between Ambala and Sunderban because the land has a very slight and continuous slope, causing the water to flow slowly and curve a lot.

Exam Tip: When explaining river features like meanders, always relate them to the gradient or slope of the land and the resultant water velocity.

Question 8. State the positive and negative aspects of Ganga River System.
Answer: The Ganga River System has both positive and negative aspects:
1. Several rivers meet the Ganga and collectively form the vast Ganga River system.
2. All these rivers carry a very large volume of water. As a result, the northern plain experiences floods almost every year.
3. These floods lead to a heavy loss of lives and property in some areas.
4. On the positive side, the plains formed by these rivers are extremely fertile, suitable for agriculture.
5. Due to these rivers, India has been able to greatly increase its prosperity in agriculture.
In simple words: The Ganga River System creates fertile land, helping India's farming thrive, but its large water volume also causes yearly floods, leading to loss of life and property.

Exam Tip: For 'positive and negative aspects' questions, ensure you clearly state both sides and provide specific examples for each to support your points.

Question 9. Give a detailed idea about Brahmaputra River System.
Answer: The Brahmaputra River System is a major trans-boundary river:
1. Brahmaputra is the only main river that is traditionally referred to with a masculine name.
2. The Brahmaputra, which is about 2900 km long, is longer than the Sindhu, but most of its flow occurs outside India.
3. It originates in Tibet near the source of the Sindhu and Satluj rivers.
4. In Tibet, it is commonly called Tsang Po.
5. In Tibet, it flows parallel to the Himalayas in an easterly direction.
6. It then makes a 'U' turn at the mountain peak called Namcha Barwa and enters India through Arunachal Pradesh, where it is known as Dihang.
7. This river, along with its tributaries Dihang, Lohit, and Kenula, is collectively known as Brahmaputra in Assam.
8. Brahmaputra is known as Jamuna when it flows into Bangladesh.
9. 'Majuli', an island in the Brahmaputra, is considered the largest riverine island in the world.
10. The Tibetan part of the Brahmaputra carries less sediment.
11. In India, the Brahmaputra flows through areas that receive very heavy rainfall, so the river carries much alluvium.
12. Many tributaries meet this river in Assam.
13. During the monsoon season, the total volume of Brahmaputra river water and its tributaries increases greatly, causing floods in Assam and Bangladesh.
14. Due to the increased sand level in this river at several places, its surface elevation becomes higher. This often leads to frequent changes in the river's course.
In simple words: The Brahmaputra is a long river starting in Tibet. It flows east, enters India as Dihang, becomes Brahmaputra in Assam, and Jamuna in Bangladesh. It carries less sediment in Tibet but much more in India due to heavy rains, causing annual floods and frequently changing its path.

Exam Tip: When describing the Brahmaputra, highlight its trans-boundary nature, different names in various regions, and the impact of heavy rainfall and sediment load in India.

Question 10. Brahmaputra gets flooded heavily during monsoon. Give reason.
Answer: The Brahmaputra river gets heavily flooded during the monsoon season for these reasons:
1. The Brahmaputra originates in the Himalayas, so it naturally contains a lot of water from melting snow and glaciers.
2. This river flows through Arunachal Pradesh and Assam in India, where many smaller rivers join it, adding more water.
3. Moreover, these regions experience very heavy rainfall during the monsoon, which significantly increases the water volume.
4. Therefore, the Brahmaputra river's water level rises greatly, leading to heavy flooding during the monsoon.
In simple words: The Brahmaputra floods during monsoon because it starts in the Himalayas, many smaller rivers join it in India, and the areas it flows through get a lot of rain, all of which greatly increase its water level.

Exam Tip: When explaining reasons for flooding, consider factors like source (snowmelt/glaciers), tributaries, and rainfall intensity in the basin area.

Question 11. Name the major peninsular rivers flowing eastwards and westwards.
Answer: The major peninsular rivers flow in two main directions:
1. The Western Ghats are considered the primary water divide for peninsular rivers, directing their flow.
2. Major rivers like Mahanadi, Godavari, Krishna, and Kaveri flow eastwards and meet the Bay of Bengal.
3. Other smaller rivers that flow eastwards and meet the Bay of Bengal include Damodar, Brahmani, Vaitami, and Suvarnarekha.
4. Major rivers such as Narmada, Tapi, Sabarmati, and Mahi (Mahisagar) flow from east to west and meet the Arabian Sea in the west.
In simple words: Major peninsular rivers like Mahanadi, Godavari, Krishna, and Kaveri flow east to the Bay of Bengal. Rivers like Narmada, Tapi, Sabarmati, and Mahi flow west to the Arabian Sea.

Exam Tip: Clearly separate the east-flowing and west-flowing rivers and list several examples for each direction to show comprehensive knowledge.

Question 12. Write a brief note on Tapi Basin.
Answer: The Tapi Basin is an important river system in central India:
1. The River Tapi is approximately 724 km long.
2. It originates from the Satpura ranges in the Betul district of Madhya Pradesh.
3. It flows in a rift valley, running parallel to the Narmada, and eventually meets the Arabian Sea.
4. Its basin covers parts of Madhya Pradesh and Gujarat.
In simple words: The Tapi river is about 724 km long. It starts in Madhya Pradesh's Satpura hills, flows through a rift valley next to the Narmada, and ends in the Arabian Sea, covering parts of Madhya Pradesh and Gujarat.

Exam Tip: For notes on river basins, always include key facts like origin, length, states covered, and the body of water it drains into.

Question 13. Write a brief note on Mahanadi Basin.
Answer: The Mahanadi Basin is a significant river system in eastern India:
1. The Mahanadi originates in the mountainous areas of Chhattisgarh.
2. It is approximately 860 km long.
3. It flows through Odisha and eventually meets the Bay of Bengal.
4. Its basin is spread across Chhattisgarh, Jharkhand, and Odisha.
In simple words: The Mahanadi river starts in Chhattisgarh, flows about 860 km through Odisha, and ends in the Bay of Bengal, with its basin covering parts of Chhattisgarh, Jharkhand, and Odisha.

Exam Tip: Similar to other river basin questions, focus on origin, length, states covered, and the final destination of the river.

Question 14. How are lakes formed?
Answer: Lakes are formed in several ways, reflecting various geological and environmental processes:
1. Some lakes are formed due to the melting of snow, especially in mountainous regions.
2. Other lakes are created when water fills natural depressions or hollows in the land.
3. Some lakes are formed as a result of tectonic movements, such as earthquakes, which can create basins.
4. A few lakes are formed due to wind activity, river actions, and human interventions (e.g., dam construction).
5. Oxbow lakes are formed in rivers that have many meanders, when a bend in the river gets cut off.
6. There are also many man-made (artificial) lakes in India, which are created by building dams.
7. Sea tides can create 'lagoon' lakes, which are coastal bodies of water separated from the ocean by a barrier.
In simple words: Lakes can form from melting snow, water filling holes in the ground, earth movements, wind, rivers, or human-made dams. Also, some are made when river bends get cut off, or by sea tides near the coast.

Exam Tip: When explaining lake formation, provide a diverse set of causes, categorizing them by natural processes (glacial, tectonic, fluvial) and human activities.

Question 15. Write a short note on importance of rivers.
Answer: Rivers have always been a vital part of human life since the dawn of humanity. The importance of rivers is immense:
1. Rivers have been an integral part of our lives since the birth of humanity.
2. They are an extremely important natural source of water and are also valuable for countless human activities.
3. Rivers fulfill various needs of people, providing water for drinking, farming, and daily use.
4. Ancient civilizations often settled and even thrived along rivers, using them for water, transport, and fertile soil.
5. Many important cities have developed along river banks, such as Delhi, Kolkata, Ahmedabad, Bharuch, and Surat.
6. They are considered a foundation for the development of agrarian countries like India, playing a crucial role in the growth of agriculture and industries.
7. River water is also utilized for drinking purposes, generating hydel (hydroelectric) power, and for navigation.
In simple words: Rivers are very important natural water sources for people, supporting farming, industries, and cities. They also provide water for drinking, electricity, and transportation, proving essential for human civilizations.

Exam Tip: When writing about the importance of rivers, cover various aspects like human settlement, agriculture, industry, transportation, energy, and cultural significance.

Question 16. How does a river get polluted? Explain.
Answer: Rivers get polluted through a combination of human activities:
1. River water is widely used for domestic activities, agriculture, and industrial production, often leading to contamination.
2. Despite people worshipping rivers and calling them 'Lokmata' (mother goddess), they contribute to their pollution.
3. In spite of these facts, we release industrial pollutants into the rivers without proper treatment.
4. Untreated sewage water from cities and towns is frequently dumped into rivers.
5. People also dispose of solid waste, religious idols, flowers, coconuts, and other items into rivers in the name of religious rituals. All these human actions contribute to river pollution.
6. The pollution of river water has become a major national problem.
7. The government is trying to prevent river pollution through various initiatives.
8. The public needs to support government initiatives and actively work to prevent river pollution.
In simple words: Rivers get polluted when people dump industrial waste, sewage, and religious offerings into them, even though rivers are important for daily life. Both industries and individuals contribute to this pollution, making it a big problem that needs government and public effort to fix.

Exam Tip: In your explanation, clearly identify the different sources of pollution (domestic, industrial, agricultural, religious) and mention the consequences, along with potential solutions.

Question 17. Rivers are called 'Lokmata'. Why? Or Why are rivers considered lifelines of human civilisation.
Answer: Rivers are often called 'Lokmata' (mother goddess) and are considered the lifelines of human civilization for several reasons:
1. Rivers are an inseparable part of a country, forming the basis of its geography and economy.
2. They transport various minerals dissolved in their waters, which makes the landmass fertile and suitable for agriculture.
3. River mouths, where freshwater meets saline oceanic water, are often the largest bioproductive areas, supporting diverse ecosystems.
4. Many major cities have developed along rivers, benefiting from water supply, transport, and fertile land.
5. People depend on rivers for numerous activities, including cattle rearing, agriculture, and various daily needs.
6. Rivers also serve as an important means for transport, as tourist attractions, and for trade and commerce.
7. Dams built across rivers help in irrigation for agriculture and in generating hydroelectricity.
8. Due to all these significant benefits, rivers are truly considered the lifeline of human civilization and are affectionately called 'Lokmata'.
In simple words: Rivers are called 'Lokmata' and lifelines because they make land fertile, help cities grow, support farming, provide transport, and create electricity, making them crucial for human life and progress.

Exam Tip: To thoroughly answer this, combine the economic, social, ecological, and cultural aspects of rivers' importance, explaining why they are central to human existence.

II. Map-based Question.

Question. On an outline map of India, mark the major.
Answer: To answer this map-based question, you would need an outline map of India. On this map, you should mark the major river systems of India. This includes:
1. **Himalayan Rivers:** The Sindhu (Indus), Ganga, and Brahmaputra river systems, along with their main tributaries.
2. **Peninsular Rivers:** The Narmada, Tapi (Tapti), Mahanadi, Godavari, Krishna, and Kaveri river systems, indicating their origin, flow direction, and eventual drainage into the Arabian Sea or the Bay of Bengal.
Marking these features clearly with proper labels will show your understanding of India's drainage systems.
In simple words: On a map of India, you should draw and label the big rivers from the Himalayas like the Ganga and Brahmaputra, and also the main rivers in the south like Narmada and Godavari, showing where they start and where they flow.

Exam Tip: For map-based questions, ensure you are familiar with the geographical locations of major rivers, their origins, and their drainage patterns. Practice marking these on blank outline maps.