India: Physical Environment

Chapter 3: Drainage System

Q. 1 What makes a river system? Explain its components.
 Answer Key Points: -
A river is a natural flow of water from higher elevation to a lower elevation under the influence of gravity. A river system contains one main river and all its tributaries.
 Components of River are: -
1) The Source: - The place from where the river originates is known as the source. Rivers usually originate from lake or melting snow on top of mountains flow downhill.
2) The course: - From the source, the river flows along a path which is known as its course. The course of a river can be divided into three parts, the upper course, the middle course and the lower course.
a) In the upper course, the river flows with great force through a narrow and shallow channel due to steep slopes. Only a small amount of water is transported.
b) In the middle course, the force of the river reduces as it flows through gentle gradient such as plains.
3) Tributaries: - Many small streams or rivers join the main river in the middle course resulting in widening of the river channel. The small streams are known as tributaries.
4) Distributaries: - In the lower course river is divided into of smaller channels, these channels are called distributaries.
5) The River Mouth: - The River finally flows into lake, sea or ocean. The part of the river that enters the sea is known as the river mouth.
Q. 2 What factors affect speed of a river?
 Answer Key Points: -
1) Gradient: - It refers to the drop in elevation of the river channel as the river flows down the hill. If the gradient is steep, the rivers flow quickly, but if the gradient is gentle the river flows slowly.

2) Roughness of the Riverbed: - As water flows through a channel; it encounters obstacles such as rocks, river bed boulders and underwater vegetation etc. All this causes friction between the flowing water and riverbed. Rougher riverbed will reduce the speed of the river due to the higher friction.
3) Wetted Perimeter (Width of the Riverbed): - When the wetted perimeter is large, more water comes in contact with the riverbed causing more friction. When the friction is high the flow of the river becomes slow on the other hand when the wetted perimeter is small, less water flow along the channel causing less friction.
4) Load of River: - Erosion in the upper course of the river leads to presence of lots of sediments which create obstacles for running water and decrease the speed of running water.
Q. 3 Explain the different drainage patterns with a diagram. Or
What are different forms of drainage system?
 Answer Key Points: -
1) Dendritic Pattern: - When number of streams joins the main stream at different points and forms a pattern like branches of a tree is called dendritic pattern. For example, the rivers of northern plain i.e. Ganga, Yamuna, etc.
2) Trellis Pattern: - When all the streams join the mainstream at right angles the pattern is called trellis pattern. For example, Peninsular Rivers such as Godavari, Krishna etc.
3) Radial Pattern: - When streams flow in different directions from a central peak or dome like structure is called radial pattern. For example, the rivers originating from the Amarkantak.
4) Rectangular Pattern: - The drainage pattern marked by right-angled bends and junctions between tributaries and the main stream is known as rectangular drainage. It is more irregular than trellis pattern.
5) Centripetal Drainage Pattern: - It is formed when rivers discharge their waters from all directions into a lake or a depression. It is known as ‘centrifugal’. These rivers form cascades (waterfall)/rapids and waterfalls. For example, Loktak lake in Manipur.
Q. 4 Give the classification of Indian rivers on the basis of discharge of water.
 Answer Key Points: - 
On the basis of discharge of water (orientations to the sea): -
1) The Arabian Sea Drainage: - 23 % of the drainage area comprising the Indus, the Narmada, the Tapi, the Mahi and the Periyar systems discharge their waters in the Arabian Sea.
2) The Bay of Bengal Drainage: - 77 % of the drainage area consisting of the Ganga, the Brahmaputra, the Mahanadi, the Krishna, etc. discharges their waters in the Bay of Bengal.
They are separated from each other through the Delhi ridge, the Aravalis and the Sahyadris (Western Ghats).
Q. 5 Give the classification of Indian rivers on the size of watershed.
 Answer Key Points: -
1) Major River Basins: - This includes the river basins with more than 20,000 sq. km of catchment area. It includes 14 drainage basins such as the Ganga, the Brahmaputra, the Krishna, the Tapi, the Narmada, the Mahi, the Pennar, the Sabarmati, the Barak, etc. and accounts for 83% of the total run off of the country.
2) Medium River Basins: - This includes the river basins with catchment area between 2,000-20,000 sq. km incorporating 44 river basins such as the Kalindi, the Periyar, the Meghna, etc. and accounts for 8% of the total run off of the country.
3) Minor River Basins: - This includes the river basins with catchment area of less than 2,000 sq. km. This includes about 55 river basins flowing in the area of low rainfall and accounts for 9% of the total run off of the country.
Q. 6 Give the difference between Perennial (Himalayan) and Non-Perennial (Peninsular) rivers. Or
Give the classification of Indian Drainage system on the basis of the mode of origin, nature of flow and characteristics.
 Answer Key Points: -

Perennial (Himalayan) Rivers Non-perennial (Peninsular) Rivers
OriginThey originate from Himalayan Mountains and receive water from rain as well as from melted snow. They originate from the Peninsular plateau region of India and receive water from the rainfall.
Nature of Flow Most of the Himalayan rivers are perennial it means they flow throughout the year. Most of the peninsular rivers are seasonal as they don't flow throughout the year.
Size They have large drainage basins with greater number of tributaries. They have small drainage basins with less number of tributaries.
Usage They are useful for irrigation, cultivation and navigation. They flow over rocky areas and are not much useful for cultivation and navigation.
Erosional Features They have cut through the mountains making gorges and V-shaped valleys. These rivers flow in a large graded and shallow valleys.
Flowing Activities They perform more erosional and depositional activities. The do not perform more erosional and depositional activities as they flow from lower elevations.
Depositional Features Most of them form deltas on their mouth. Most of them form estuaries on their mouth.
Examples The Indus, the Ganga and Brahmaputra are the examples of Perennial Rivers. Narmada Tapi Krishna Kaveri Godavari Mahanadi etc. are the major Peninsular Rivers.

Q. 7 Difference between Delta and Estuary. 
 Answer Key Points: -
Delta
Estuary
1. Shape
Delta is a triangular land mass formed by deposition of material transported by rivers at their river.
It is a partly enclosed body of water along the coast where fresh water from the rivers and streams meets with the saltwater of the oceans.
2. Formation
They are formed on the tide-less sea coast near the mouth of river where sediment brought by the rivers is deposited.
They are result of strong currents and high tides at the mouth of river where no deposition takes place.
3. Suitability
They are rich agriculture ground.
They are rich fishing ground and are suitable for inland transportation.
4. Rivers
Rivers like Krishna, Kaveri, Mahanadi, Godavari form deltas.
Narmada, Tapi and many other westward flowing Peninsular rivers forms estuaries.
Q. 8 Explain the main features of Indus River system.
 Answer Key Points: -
1) Origin: - River Indus rises in Tibet from the Bokhar Chu (glacier) in northern slopes of Mt. Kailash near Mansarowar Lake. In Tibet, it is known as ‘Singi Khamban; or Lion’s mouth.
2) Length: - River Indus is one of the longest rivers in the world having length of 2900 (3180) km. (in India 1114).
3) Direction of Flow: - Flowing west it enters India in the Ladakh union territory.
4) Tributaries: - In Kashmir region it is joined by many tributaries of Zaskar, the Nubra, the Shyok and the Hunza. The Satluj, the Beas, the Ravi, the Chenab and the Jhelum join together to enter the Indus near Mithankot in Pakistan.
5) Get down to Plains: - The Indus flows through Baltistan and Gilgit Region and leaves Himalayas at Attock in Kashmir region and enters into Pakistan near Chilas in the Dardistan region.
6) Depositional Feature: - In Pakistan the Indus flows southwards and forms ‘Sapt Sindhu’ delta in Karachi and drains into the Arabian Sea.
Q. 9 Give the brief description of ‘PanchNad’ tributaries of river Indus.
 Answer Key Points: -
1. Jehlum
The Jhelum, an important tributary of the Indus, rises from a spring at Verinag situated at the foot of the Pir Panjal in the south-eastern part of the valley of Kashmir.
1. The total length of the Jhelum is about 725 km.
2. It flows through Srinagar and the Wular Lake before entering Pakistan through a deep narrow gorge.
3. It joins the Chenab near Jhang in Pakistan.
4. It is navigable between Anantnag and Baramulla and has ‘Tulbul Navigation Project’ near Wular Lake.
2. Chenab
It is formed by two streams, the Chandra (115km) and the Bhaga (60km), which join at Tandi near Keylong in Himachal Pradesh. So, it is known as Chenab or Chandrabhaga.
1. The Chenab is the largest tributary of the Indus with length of 1180 km.
2. It rises in the upper Himalayas in the Lahaul and Spiti district of Himachal Pradesh state and flows between the Pir Panjal and the Greater Himalayas.
3. In India, it flows through the Jammu region of Jammu and Kashmir into the plains of Punjab and Pakistan, before flowing into the Indus River near the city of Uch Sharif.
4. The important hydel projects installed across the Chenab are Salal, Dulhasti and Baglihar.
3. Ravi
It rises west of the Rohtang pass in the Kullu hills of Himachal Pradesh and flows through the Chamba valley of the state.
1. It drains the area between the Pir Panjal and the Dhaola Dhar ranges with the total length of 720 km.
2. In Pakistan it joins the Chenab River near Sarai Sidhu.
3. It enters Punjab Plains near Madhopur and later enters Pakistan below Amritsar.
4. It is also called 'The river of Lahore' since that great city is located on its eastern bank.
4. Beas
The Beas originates from the Beas Kund near the Rohtang Pass, close to the source of the Ravi.
1. It's the only river in the Indus system that lies entirely within the Indian Territory with total length of about 470 km.
2. It drains Pir Panjal and Dhauladhar range and meets the Satluj River near Harike in Punjab.
3. The Beas town in the Amritsar district of Punjab lying at its banks is named after the river.
4. It creates a boundary with the Kangra district, separating the Gurdaspur and Hoshiarpur districts.
5. Sutlej
The Satluj originates in the ‘Raksas tal’ near Mansarovar in Tibet where it is known as Langchen Khambab.
1. Out of its total length of 1,450 km, it flows for 1,050 km in Indian Territory.
2. It flows almost parallel to the Indus for about 400 km before entering India, and comes out of a gorge at Rupnagar (Ropar).
3. It passes through the Shipki La on the Himalayan ranges and enters the Punjab plains.
4. It is a very important tributary as it feeds the canal system of the Bhakra Nangal project in Punjab.
5. From near Ferozepur to Fazilka it forms the boundary between India and Pakistan for nearly 120 km.
6. After receiving the collective drainage of the Ravi, Chenab and Jhelum rivers during its entire journey, it joins the Indus River near Mithankot.
Q. 10 Explain the main features of Ganga River System.
 Answer Key Points: -
1) Origin: - The Ganga River originates from the Gangotri glacier near 'Goumukh/ Gaumukh' in the Uttarkashi district of Uttarakhand, here it is known as the 'Bhagirathi'
2) Main Source of Water: - The Bhagirathi meets the Alaknanda at Devprayag in Uttarakhand, here it is known as the Ganga.
3) Get Down To Plains: - At Haridwar Ganga emerges from the mountains on to the plains.
4) Left Bank Tributaries: - The Ganga is joined by many left bank tributaries from the Himalayas such as the Ghaghara, the Gandak and the Kosi.
5) Right Bank Tributaries: - The Yamuna and the Peninsular Rivers such as the Chambal, the Betwa, and the Son are the main right Bank tributaries of the Ganga.
6) Length: - The length of Ganga River is 2525 km covers about 8.6 lakh sq. km areas in India.
7) Bifurcation (Division): - The Ganga enters Bangladesh and called Padma, here it flows southward and is joined by river Brahmaputra (Jamuna) and is collectively called Meghna. The other distributary called the Bhagirathi flow through West Bengal and finally discharges itself into the Bay of Bengal near the Sagar Island.
8) Depositional Activity: - The Ganga River formed world’s largest delta called Sunderbans in West Bengal.
Q. 11 Give the main features of Yamuna River system.
 Answer Key Points: -
1) Origin: - The Yamuna also known as Yami River originates from the Yamunotri glacier on the western slopes of Banderpunch range in the Uttarkashi district of Uttarakhand.
2) Get down to Plains: - It enters into plains at Dak Pathar in Dehradun district Uttarakhand.
3) Left bank Tributaries: - The Yamuna is joined by many left bank tributaries from the
Himalayas such as the Hindan, the Rind, the Sengar, the Varuna, etc.
4) Right bank Tributaries: - The Peninsular Rivers such as the Chambal, the Sind, the Betwa, and the Ken are the main right Bank tributaries of the Yamuna.
5) Length: - The Yamuna is the second-largest tributary river of the Ganga with 40.2% of the entire Ganga Basin, and the longest tributary in India with total length of 1,376 km.
6) Bifurcation (Division): - At the Hathni Kund Barrage (A concrete barrage located on the Yamuna River in Yamuna Nagar district of Haryana state) its waters are diverted into two large canals: - the Western Yamuna Canal flows towards Haryana and the Eastern Yamuna Canal towards Uttar Pradesh.
7) Other Feature: - It merges with the Ganga at Triveni Sangam, Prayagraj, in Allahabad which is a site of the Kumbh Mela, a Hindu festival held every 12 years.
Q. 12 Give the brief description of major tributaries of River Ganga.
 Answer Key Points: -
Name of River
Features
1. Chambal
1. The 1,024 km. long Chambal River originates from the Singar Chouri peak on the northern slopes of the Vindhyan Range in Wastern Madhya Pradesh.
2. It flows through the Malwa Plateau and is famous for its badlands topography called the Chambal ravines
3. The Gandhi Sagar dam is the first of the four dams built on the Chambal River, located on the Rajasthan-Madhya Pradesh border.
4. The Rana Pratap Sagar dam is a dam located 52 km downstream of Gandhi Sagar dam on across the Chambal River in Chittorgarh district in Rajasthan.
5. It forms the boundary between Rajasthan and Madhya Pradesh before turning southeast to join the Yamuna in Etawah district of Uttar Pradesh.
2. Gandak
1. The Gandak comprises two streams, namely Kali-Gandak and Trishul-Ganga, rises in the Nepal Himalayas between the Dhaulagiri and Mount Everest and drains the central part of Nepal.
2. The Gandaki River, also known as the Narayani and the Gandak, is one of the major rivers in Nepal and a left bank tributary of the Ganga River in India.
3. It enters the Ganga plain in Champaran district of Bihar and joins the Ganga at Sonpur near Patna.
4. Its total length is about 814 km.
5. This river provides water for a major Irrigation cum Hydroelectric power facility at the Indo-Nepal border at Valmikinagar.
3. Ghaghara
1. Ghaghara, also called Karnali in Nepal is a perennial river originating on the Tibetan Plateau near Lake Manasarovar.
2. It cuts through the Himalayas in Nepal and joins the Sharda River at Brahmaghat in India. Here together they form the Ghaghara River.
3. With a length of 507 km, it is the longest river in Nepal. The total length of Ghaghara River up to its confluence with the Ganges at Revelganj in Bihar is 1,080 km.
4. It is the largest tributary of the Ganges by volume and the second longest tributary of the Ganges by length after Yamuna and become a major left bank tributary of the Ganges.
5. The river has a high flood frequency and has shifted its course several times.
1. The Kosi or Koshi is a trans-boundary river which flows through Tibet, Nepal and India.
2. The Kosi River is 720 km long and drains an area in Tibet, Nepal and Bihar.
4. Kosi
3. The main stream of Kosi is called Arun, rises in the north of Mount Everest in Tibet.
4. After crossing the Central Himalayas in Nepal, it is joined by the Son Kosi from the West and the Tamur Kosi from the east. The Kosi River is also known as Saptakoshi after uniting its seven upper tributaries.
5. The Kosi River is known as the "Sorrow of Bihar" as the annual floods affect about 21,000 km2 which disturb the rural economy.
5. Ramganga
1. It rises in the lower Himalayas near the Lohba village in the Garhwal district of Uttarakhand.
2. The river flows entirely in the states of Uttarakhand and Uttar Pradesh with the total length of 596 km.
3. The river enters the plains at Kalagarh near the border of the Garhwal district, where the famous Ramganga dam has been constructed.
4. Beyond Kalagarh, the river flows in a southeasterly direction and finally joins the Ganga on its left bank near Kanauj in the Fategarh district.
6. Damodar
1. The Damodar River rises in the hills of the Chotanagpur plateau and flows through a rift valley.
2. Rich in mineral resources, the valley is home to large-scale mining and industrial activity.
3. Several dams have been constructed in the valley, for the generation of hydroelectric power. The valley is called “the Ruhr of India”.
4. Earlier it was known as the ‘Sorrow of Bengal’ because of creating large scale floods in the plains of West Bengal.
5. With the establishment of Damodar Valley Corporation (DVC) 1948, {an Indian governmental organization which operates in the Damodar River area of West Bengal and Jharkhand states of India.} the devastating river Damodar has turned from a ‘River of Sorrow’ to a ‘River of Opportunities.
6. It follows a generally eastward course for 592 km through West Bengal to join the Hugli (Hooghly) River southwest of Kolkata (Calcutta).
7. Sarda
1. The Sarda or Saryu River rises in the Milan glacier in the Nepal Himalayas where it is known as the Goriganga.
2. Along the Indo-Nepal border, it is called Kali or Chauk, where it joins the Ghaghara.
3. It is known as the Sarda after it reaches the plains near Tanakpur in Champawat district of Uttarakhand.
4. The length of this river is 252 km and it forms the boundary between Nepal and Kumaon region of Uttrakhand.
8. Mahananda
1. The Mahananda is a trans-boundary river that flows through the Indian states of Bihar and West Bengal, and Bangladesh.
2. It is the last left bank tributary of the Ganga rising in the Darjeeling hills.
3. It flows through Mahananda Wildlife Sanctuary and descends to the plains near Siliguri.
4. The total length of the river is 360 km. out of which 324 km. are in India and 36 km. are in Bangladesh.
9. Son
1. The Son or Sone is major right bank tributary of Ganga River, originating in the Amarkantak plateau (Madhya Pradesh) close to the origin of the Narmada.
2. After forming a series of waterfalls at the edge of the plateau, it joins the Ganga near Danapur in Patna district of Bihar.
3. It flows for a distance of 784 km from its source.
Q. 13 Explain the main features of Brahmaputra River System. 
 Answer Key Points: -
1) Origin: - The Brahmaputra River originates in Tibet east of Mansarowar Lake very close to the sources of the River Indus and the River Satluj and is called Tsangpo (Purifier). (From Chemayungdung Glacier).
2) Drainage Area: - It flow eastwards parallel to the Himalayas, on reaching the Namcha Barwa it takes U turn and enters India in Arunachal Pradesh through a Gorge.
3) Sub-Names: - Here it is called the Dihang and it is joined by the River Dibang and the River Lohit and is called Brahmaputra.
4) Length: - Its total length is 2900 km out of which about 1,700km is in Tibet, 900 km is in India and 300 km is in Bangladesh.
5) Source of Water: - In India it passes through a region of high rainfall and receives large amount of water and silt.
6) Depositional Feature: - It has a braided channel in its entire length in Assam and forms world's largest riverine island Majoli (Majuli) here.
7) Flowing Activities: - It is responsible for creating a danger of floods in Assam and Bangladesh.
8) Drained Point: - In Bangladesh it is known as Jamuna, after joining River Padma (Ganga) it is called Meghna and drains its water into Bay of Bengal through Sagar Island (India).
Q. 14 Explain the evolution of Peninsular Drainage System. Or
What are major geological events in the distant past have shaped the present drainage systems of Peninsular India?
 Answer Key Points: -
1) Subsidence of the western side of the Peninsula leading to its submergence below the sea during the early tertiary period.
2) Upliftment of the Himalayas when the northern side of the peninsular block was subjected to subsidence and the consequent trough faulting.
3) Slight tilting of the peninsular block from north-west to the south-eastern direction gave orientation to the entire drainage system towards the Bay of Bengal during the same period.
Q. 15 Explain the main features of Mahanadi River system.
 Answer Key Points: -
1) Origin: - The Mahanadi rises near Sihawa in Raipur district of Chhattisgarh and runs through Odisha to discharge its water into the Bay of Bengal.
2) Drainage Area: - The Mahanadi basin covers parts of the states of Chhattisgarh, Jharkhand, Odisha and Maharashtra.
3) Length: - It is 851 km long and its catchment area spreads over 1.42 lakh sq. km.
4) Depositional Feature: - It deposits more silt than any other river in the Indian subcontinent.
5) Flowing Activities: - The Mahanadi was known for its devastating flood in Odisha, thus it was called ‘the sorrow of Odisha’.
6) Uses: - Presently, a network of Canals, barrages and Hirakud reservoir keep the river well in control and that water is used for irrigation.
7) Tributaries: - Some important tributaries of Mahanadi are Seonath, Mand, Hasdeo, Ong, Parry River, Jonk, Telen etc.
Q. 16 Explain the main features of Godavari River system.
 Answer Key Points: -
1) Origin: - The Godavari rises from the slopes of Western Ghats in the Nasik district of Maharashtra.
2) Length: - It is the largest Peninsular River with the length of 1465 km so it is also called ‘Dakshin Ganga’.
3) Drainage ßasin: - Its basin covers parts of Maharashtra 49% Madhya Pradesh and Chhattisgarh 20 % and rest in Telangana Andhra Pradesh and Orissa.
4) Tributaries: - Godavari is joined by number of tributaries such as the Purna, the Indravati, the Pranhita, the Manjra, the Wainganga and the Penganga.
5) Depositional Features: - The tributaries of the Godavari River formed Konaseema or God's Own Creation delta in coastal region of Andhra Pradesh.
Q. 17 Explain the main features of Krishna River system. 
 Answer Key Points: -
1) Origin: - The Krishna rises near Mahabaleshwar in Sahyadri. (Western Ghats)
2) Length: - It is the second largest east flowing Peninsular River and 4th largest river of India with total length of 1401 km.
3) Tributaries: - The important tributaries are the Koyna, the Tungabhadra, the Musi, the Ghatprbha and the Bhima.
4) Drainage Area: - Out of total catchment area of the Krishna 27% lies in Maharashtra 44% in Karnataka, 14% in Telangana and 15% in Andhra Pradesh.
5) Dams: - Nagarjuna Sagar Dam is built across the Krishna River at Srisailam and Nagarjuna Sagar which extended the border between Guntur district, Andhra Pradesh and Nalgonda district, Telangana.
Q. 18 Explain the main features of Kaveri/ Cauvery River system. 
 Answer Key Points: -
1) Origin: - The Kaveri rises in Brahmagiri hills of Kogadu district in Karnataka.
2) Length: - Its total length is about 760 km.
3) Drainage ßasin: - It drainage basin falls in Karnataka about 41%, Kerala 03% and Tamil Nadu 56%.
4) Tributaries: - Its main tributaries are the Amravati, the Bhavani, the Hemavati and the Kabini.
5) Drained Point: - It drains its water in Bay of Bengal in the south of Cuddalore district in Tamil Nadu.
Q. 19 Explain the main features of Narmada River System.
 Answer Key Points: -
1) Origin: - The Narmada rises in the Amarkantak hills in Madhya Pradesh and flows towards the West in the rift valley formed due to faulting.
2) Tributaries: - All the tributaries of the Narmada are very short and most of these join the main stream at right angles.
3) Size: - Narmada basin extends over an area of 98,796 sq. km. which is nearly 3% of the total geographical area of the country.
4) Length: - The Narmada Basin covers parts of Madhya Pradesh and Gujarat with the total length of 1,312 km.
5) Features: - It forms a
picturesque gorge in marble rocks and Dhuandhar waterfall near Jabalpur.
6) Depositional Activity: - It forms 27 km long estuary before entering into the Arabian Sea.
7) Dam: - ‘The Sardar Sarovar Project’ has been constructed on this river.
Q. 20 Explain the main features of Tapi (Tapti) River system.
 Answer Key Points: -
1) Origin: - Tapi or Tapti originates from Multai in the Betul district of Madhya Pradesh.
2) Direction of Flow: - The Tapi also flows westward in a rift valley parallel to the Narmada but it is much shorter in length.
3) Tributaries: - Purna, Girna, and Panjhra are the 3 major tributaries of the Tapi River, flow from the south in Maharashtra state.
4) Length: - It is 724 km long and drains an area of 65,145 sq. km.
5) Size: - Nearly 79% of its basin lies in Maharashtra, 15% in
Madhya Pradesh and the remaining 6% in Gujarat.
Q. 21 Explain the main features of Luni River. 
 Answer Key Points: -
1) Introduction: - Luni is the largest river system of Rajasthan, west of Aravali.
2) Origin: - It originates near Pushkar in two branches, i.e. the Saraswati and the Sabarmati, which join with each other at Govindgarh. From here, the river comes out of Aravali and is known as Luni.
3) Etymology: - The Luni derived its name from the Sanskrit lavanavari (“salt river”) and is so called because of its excessive salinity.
4) Tributaries: - The Jowai, Sukri, and Jojari rivers are the major tributaries of the Luni River.
5) Length: - With a total length of 530 km, the Luni is the only major river of the area, and it serves as an essential source of irrigation waters.
6) Nature of Flow: - It is a seasonal river, receives much of the drainage of the southwest slopes of the Aravalli Range.
7) Direction of Flow: - It flows towards
the west till Telwara and then takes a southwest direction to join the Rann of Kuchchh.
Q. 22 Give a brief description of smaller rivers of flowing towards the Western coast of India.
 Answer Key Points: -
1. Shetruniji
1. The Shetruniji is river which rises near Dalkahwa in Amreli district of Gujarat.
2. Its total length is about 277 km. and discharges its water into the Gulf of Cambay (Khabhat).
2. The Bhadra
1. The Bhadra or Bhadar River originates near Aniali village in Rajkot district.
2. Its total length is about 200 km. it empties into the Arabian Sea near Porbandar in Gujarat.
3. Dhadhar
1. The Dhadhar rises near Ghantar village in Panchmahal district from Pavagadh Hill (Part of southern Aravalli Range) in Gujarat.
2. Its total length is about 142 km. it empties into the Gulf of Cambay (Khabhat).
4. Sabarmati
1. The Sabarmati River is one of the major west-flowing rivers in India, originates in the Aravalli Range of the Udaipur District of Rajasthan and meets the Gulf of Khambhat of Arabian Sea.
2. Its total length is about 371 km among which 48 km of the river length is in Rajasthan, and 323 km is in Gujarat.
5. Mahi
1. The Mahi River origin is Minda Village in the western Vindhya Range, which is situated in Dhar district Madhya Pradesh.
2. Its total length is about 580 km. and it enters the sea by a wide estuary before Gulf of Khambhat.
3. This river crosses the Tropic of Cancer twice.
4. Its drainage is shared by the states of Rajasthan and Gujarat also.
5. It is popularly described as Mahisagar due to the vastness of the river. The newly formed Mahisagar district in Gujarat derives its name from this pious (holy) river.
6. Vaitarna
1. The Vaitarna River originates from the Trimbak hills in Sahyadri mountain ranges in Nasik district of Maharashtra.
2. Vaitarna River is just 2 km away from India’s second longest river Godavari.
3. Its total length is about 154 km. and it enters the Arabian Sea through the states of Maharashtra.
4. Jhow and Wadhiv islands lie in its estuary. Arnala Island lies off its mouth.
5. It has three major dams which supply water to Mumbai.
7. Kalinadi
1. The Kalinadi or Kali Nadi rises from Belgaum district of Karnataka and falls in the Karwar Bay.
2. The river is the lifeline to some 4 lakh people in the Uttara Kannada district and supports the livelihoods of 10000 of people including fishermen on the coast of Karwar.
3. There are many dams built across this river for the generation of electricity.
4. The river runs 184 kilometers before joining Arabian Sea.
8. Bedti
1. Gangavalli River also called Bedti River originates from the Western Ghats the south of Dharwad as Shalmala River and flows to meet the Arabian Sea just after the Ganga temple in the village Gangavalli, the River is called the Gangavalli name from the Goddess Ganga.
2. The source of Bedti River lies in Hubli Dharwar and travels a course of 161 km.
3. On its course towards the Arabian Sea, the river falls from a height of 180 meter at a point called Magod and is popularly known as The Magod Falls.
9. Sharavati
1. The Sharavati is another important river in Karnataka flowing towards the west.
2. The Sharavati originates in Shimoga district of Karnataka and drains a total length of 128 km.
3. The famous Jog Falls, the second highest plunge waterfall in India, located about 24 km from Sagara (A taluk in Shimoga district) are formed by this river.
10. Mandovi
1. The Mandovi also known as Mahadayi or Mhadei River (Gomati in a few places) is described as the lifeline of Goa.
2. It originates from a cluster of 30 springs at Bhimgad in the Western Ghats in the Belagavi district of Karnataka.
3. The river has a total length of 81 km among which 35 km in Karnataka, 1 km in Maharashtra and 45 km in Goa.
4. The waters of the Mandovi and Zuari both flush out into the Arabian Sea at Cabo Aguada, a common point forming the Mormugao harbour.
5. Panaji, the state capital and Old Goa, the former capital of Goa, are both situated on the left bank of the Mandovi.
11. Zuari
1. The Zuari or Zuvari River is the largest river in the state of Goa.
2. About 92 km long, Zuari River is a tidal river which originates at Hemad-Barshem in the Western Ghats.
3. The Zuari is also referred to as the Aghanashani in the interior regions.
4. The Cumbarjuem Canal linking the two rivers of the Zuari and Mandovi, has enabled ships navigate to the interior regions to the iron ore mines.
5. The port city of Vasco da Gama, Goa lies on the mouth of the Zuari River.
12. Bharathapuzha
1. Bharathapuzha also known as the Nila, rises near Annamalai hills (also called Elephant Mountains) in Tamil Nadu. It is also known as Ponnani.
2. With a length of 209 km. it is the second longest river in Kerala after the Periyar.
3. It empties into the Lakshadweep Sea at Ponnani.
13. Periyar
1. Periyar (meaning: big river) is the longest river and the river with the largest discharge potential in the state of Kerala.
2. The Periyar is a perennial river and has a total length of about 244 km, drains into Arabian Sea.
3. The Periyar is an inter-State river seems to have a source lies in the remote forests of the Periyar Tiger Reserve, in the Western Ghats, but there is conflict between the states of Tamil Nadu and Kerala about the origin of the River.
14. Pamba
1. The Pamba River has a total length of about 177 km. it empties into the Vemobanad Lake.
2. The Pamba (also called Pampa River) is the third longest river in the South Indian state of Kerala after Periyar and Bharathappuzha.
3. The Pamba originates at Pulachimalai hill in the Peerumedu plateau in the Western Ghats in Kerala.
Q. 23 Give a brief description of smaller rivers of flowing towards the Eastern coast of India.
 Answer Key Points: -
Name of River
Features
1. Subarnrekha
1. The Subarnarekha River (also called the Swarnarekha River) flows through the Indian states of Jharkhand, West Bengal and Odisha.
2. After originating near piska/nagri, near Ranchi (Jharkhand), it joins the Bay of Bengal near Talsari Beach in the Baleswar district of Odisha.
3. The total length of the river is 395 km.
2. Baitarni
1. The Baitarani (Vaitarani) originates from the Gonasika / Guptaganga (Cow Nose Shaped) hills in Gonasika of Keonjhar district in Odisha.
2. It starts flowing over a stone looking like the nostril of a cow.
3. Afterwards for about half a km the river flows underground and is not visible from outside, so it is called Guptaganga or the Gupta Baitarani.
4. The river travels a distance of 360 km. to drain into the Bay of Bengal after joining of the Brahmani at Dhamra mouth near Chandabali.
5. The river has 65 tributaries, of which 35 join from the left side and 30 join from the right side.
3. Brahmani
1. The Brahmani is formed by the confluence of the rivers South Koel and Sankh near the major industrial town of Rourkela in Odisha.
2. Together with the river Baitarani, it forms a large delta before emptying into the Bay of Bengal at Dhamra.
3. At about 480 kilometres (300 mi) long, the Brahmani is the second longest river in Odisha after the Mahanadi.
4. Vamsadhara
1. The Vamsadhara River originates in the Kalahandi district of Odisha and runs for a distance of about 254 km, and it joins the Bay of Bengal at Kalingapatnam, Andhra Pradesh.
5. Penner
1. The Uttara Pinakini (also known as Pennar, Penner, Penneru and pennar) is a river of southern India.
2. It rises in the Nandi Hills in Chikkaballapur District of Karnataka state, and runs north and east through the states of Karnataka and Andhra Pradesh to empty into the Bay of Bengal.
3. It is 597 km. long, with a drainage basin covering in Karnataka and Andhra Pradesh.
4. The river basin lies in the rain shadow region of Eastern Ghats and receives 500 mm average rainfall annually.
6. Palar
1. The Palar rises in the Nandi Hills in Chikkaballapura district of Karnataka state and confluence into the Bay of Bengal at Vayalur.
2. With a total length of 348 km. it flows 93 km in Karnataka, 33 km in Andhra Pradesh and 222 km in Tamil Nadu.
7. Vaigai
1. The Vaigai River originates in Varusanadu Hills, the Periyar Plateau of the Western Ghats range in the Tamil Nadu.
2. The river empties into the Palk Strait near Uchipuli, close to Pamban Bridge in Ramanathapuram District after covering the total length of 258 km.
Q. 24 What factors determine volume of water in a river?
 Answer Key Points: -
Factors affecting the volume of water in a river are: -
1) Size of the Drainage Basin: - If the drainage basin is large, the volume of water in the river will be more. The amount of rainwater that flows on the ground adds into the river or lake and leads to raise the river bed. But, if the drainage basin is small volume of water in the river will be less because there is less surface area for the rain to fall on.
2) Vegetation: - Grass and leaves of tress reduces flow of rainwater and allow more water to sweep into the ground. As a result, the amount of surface runoff reduces. Therefore, the volume of water in the river is less where vegetation is dense. Less vegetation prevent rainwater from getting trapped, and allowing more water to flow through a surface runoff.
3) Nature of Rocks: - In area with porous rocks, much of the rainwater seeps into the ground. In such areas, surface run off is less and water flowing into the river channel will also be less.
4) Climate: - In areas with hot and wet climate such as equatorial area, volume of water rivers will be high. However, the amount of water will be less in areas with dry climate receiving less rainfall.
Q. 25 Explain about flood prone areas of India.
 Answer Key Points: -
1) The intense monsoon rains from south-west increases the water level in rivers like Brahmaputra, Ganga, Yamuna etc. which in turn leads to floods in the nearby areas.
2) The states falling within the category of “India Flood Prone Areas” are West Bengal, Orissa, Andhra Pradesh, Kerala, Assam, Bihar, Gujarat, Uttar Pradesh, Haryana and Punjab.
3) The major flood prone areas in India are the river banks and deltas of Ravi, Yamuna-Sahibi, Gandak, Sutlej, Ganga, Ghaggar, Kosi, Teesta, Brahmaputra, Mahanadi, Mahananda, Damodar, Godavari, Sabarmati and their tributaries.
4) During the rainy season, much of the water is wasted in floods and flows down to the sea. Similarly, when there is a flood in one part of the country, the other area suffers from drought.
Q. 26 Can the problems of flood and drought be solved or minimised by transferring the surplus water from one basin to the water deficit basins? Do we have some schemes of inter-basin linkage?
 Answer Key Points: -
Yes, these problems be solved or minimised by transferring the surplus water from one basin to the water deficit basins as during the rainy season, much of the water is wasted in floods and flows down to the sea. When there is a flood in one part of the country, the other area suffers from drought.
 We do have such schemes: -
1) Periyar Diversion Scheme
2) Indira Gandhi Canal Project
3) Kurnool-Cuddapah Canal
4) Beas-Satluj Link Canal
5) Ganga-Kaveri Link Canal.
Q. 27 State the advantages of Rivers and Lakes. Or
Why Rivers and Lakes are important for the economy of a country.
 Answer Key Points: -
1. Tourist Attraction: - Lakes are the attraction of tourists as these are the sources of re-creation and enjoyment.
Attraction Of Settlement: - Rives are the attraction of human settlement as these provide water for domestic use and irrigation and fertile soil for agricultural activities.
2. Regulate Flow Of Water: - Lakes can store extra water during heavy rainfall thus control flow of water.
Source Of Energy/Electricity: - Number of multi-purpose projects ad dams are made on rivers which provide cheap hydroelectricity.
3. Provide Water In Dry Season: - Lakes provide regular water supply during dry season.
Provide Water For Irrigation: - Rivers are the main source of water for irrigation.
4. Control Over Climate: - Lakes have a moderate influence over climate of a place.
Source Of Water For Industries And Transportation: - Rivers are medium of transportation and their water
5. Source Of Salt And Other Aquatic Food: - Lakes also provide salt and other aquatic food to people.
Makes Soil Fertile: - Most of the rivers get flooded during rainy season and deposited a large amount of silt which makes soil fertile.
Q. 28 What are the socio-economic advantages of inter-linking of rivers in India? 
 Answer Key Points: -
1) It can solve the problem of water management and its distribution because availability of river water is not equal from the point of view of time and place due to non- regular flow of some Indian Rivers.
2) Inter-linking of rivers also solve the problems of floods during rainy seasons which cause loss of life and property, ruins agriculture and situation of droughts.
3) It will solve the problem of drinking water and millions of rupees will be saved.
4) It will also lead to increase in productivity and will improve economic condition of farmers.
Q. 29 What are some problems in river water usage? Or
What are the problems associated with the use of river water? 
 Answer Key Points: -
1) Water scarcity or lack of water availability in sufficient amount.
2) River water pollution.
3) Load of silt in the river water.
4) Uneven seasonal flow of water.
5) River water disputes between states.
6) Shrinking of channels due to the extension of settlements towards the river banks.
7) Some of these water-borne diseases are Typhoid, Cholera, Paratyphoid Fever, Dysentery, Jaundice, and Malaria.
8) Chemicals in the water also have negative effects on our health. Pesticides – can damage the nervous system and cause cancer because of the carbonates and organophosphates that they contain.
Q. 30 Give sources of Water Pollution? Suggest some ways to prevent River Water pollution.
 Answer Key Points: -
 Sources of Water Pollution: -
1) Waste From Industries: - The factories and industries discharge their wastewater and solid waste nearby rivers which cause water pollution.
2) Sewage Waste: - Disposal of sewage of urban centers into rivers is also responsible for water pollution.
3) Agricultural Runoff: - Heavy rainfall causes agricultural runoff and overuse of fertilizers and pesticides makes it source of water pollution.
4) Leakage of Oil Tankers: - Water in oceans gets polluted by the leakage of oil from oil tankers.
5) Acidic Rain: - Acidic rain also played an important role polluting open sources of water.

 Methods To Control Water Pollution: -
1) The waste product from factories should not be allowed to dump into rivers.
2) The waste material should be treated before it allowed discharging into the river.
3) Sewage of urban Centre should not be allowed to fall into rivers at any cost.
4) Leakage of oil tanker should be reduced.
5) Steps must be taken to control and reduce air pollution.
6) Common public should be aware about the effect of water pollution.