NCERT Geography Book for Class 9: Drainage - Chapter 3 Online Reading and PDF Download
Class 9 Geography Chapter 3 Drainage PDF Download
Drainage is the process of removal of excess water from the land surface or the subsurface by natural or artificial means. A drainage system is a network of watercourses or drains that carry away the surplus water. A drainage basin is an area of land that drains all the water to a common outlet such as a river, lake or sea. A watershed is the boundary that separates one drainage basin from another.
Drainage is an important topic in geography as it influences various aspects of the physical and human environment such as climate, soil, vegetation, agriculture, transportation, etc. In this chapter, we will learn about the different types of drainage patterns, the major rivers of India and their characteristics, and the drainage basins of India and their features.
class 9 geography chapter 3 drainage pdf download
The main objectives of this chapter are to:
Understand the meaning and significance of drainage in geography
Identify and describe the different types of drainage patterns
Recognize and explain the characteristics and courses of the major rivers of India
Analyze and compare the drainage basins of India and their river systems
Develop geographical skills such as map reading, data interpretation and diagram drawing
Types of Drainage Patterns
A drainage pattern is the arrangement or shape of a river system in a region. It depends on various factors such as geological structure, topography, slope, climate, rainfall, vegetation and human activities. There are different types of drainage patterns such as:
Dendritic: This is the most common type of drainage pattern. It resembles a tree with many branches. It develops in areas where the underlying rock is uniform and horizontal or gently sloping. The streams join at acute angles forming a dendritic network. Examples: Ganga river system, Deccan plateau rivers.
Trellis: This type of drainage pattern forms in areas where hard and soft rocks alternate in parallel bands. The main river flows along a valley eroded by a soft rock while its tributaries cut across hard rocks at right angles forming a trellis-like pattern. Examples: Indus river system, Satluj river system.
Radial: This type of drainage pattern develops when streams flow in different directions from a central highland or peak. The streams radiate outwards like spokes of a wheel. Examples: Narmada river system, Amarkantak hills.
Rectangular: This type of drainage pattern forms in areas where rocks are jointed or faulted at right angles. The streams follow rectangular courses along these joints or faults forming right-angled bends. Examples: Chambal river system, Rewa plateau.
Deranged: This type of drainage pattern forms in areas where the original drainage system has been disturbed or destroyed by natural or human factors such as glaciation, volcanism, erosion, deposition, etc. The streams have irregular and disconnected courses forming lakes, swamps and marshes. Examples: Canadian Shield, parts of Rajasthan.
Major Rivers of India
India has a rich and diverse river system that drains almost 75% of its land area. The rivers of India can be classified into two broad categories based on their origin and discharge:
Himalayan rivers: These are the rivers that originate from the Himalayan mountains or the Tibetan plateau. They are perennial, meaning they flow throughout the year due to snowmelt and rainfall. They have long courses, large basins, high discharge and sediment load. They form meanders, oxbow lakes, floodplains, deltas and estuaries. Examples: Indus, Ganga, Brahmaputra.
Peninsular rivers: These are the rivers that originate from the peninsular plateau or the central highlands of India. They are seasonal, meaning they depend on monsoon rainfall for their flow. They have shorter courses, smaller basins, lower discharge and sediment load. They form rapids, waterfalls, gorges, canyons and lagoons. Examples: Narmada, Tapi, Godavari, Krishna, Kaveri.
The following table summarizes the characteristics and courses of some of the major rivers of India:
River
Origin
Length (km)
Basin Area (sq km)
Tributaries
Features
Indus
Mansarovar Lake in Tibet
2880 (709 in India)
321289 (114000 in India)
Zanskar, Shyok, Gilgit, Kabul, Chenab, Ravi, Beas, Sutlej
Forms a large delta in Pakistan; flows through Ladakh and Punjab; one of the longest rivers in Asia; part of the Indus Valley Civilization
Ganga
Gangotri glacier in Uttarakhand
2525
861452
Yamuna, Ghaghara, Gandak, Kosi, Son, Gomti, Chambal
Forms a large delta with Brahmaputra in West Bengal; flows through Uttar Pradesh, Bihar and West Bengal; one of the most sacred rivers in Hinduism; one of the most polluted rivers in the world
Brahmaputra
Chemayungdung glacier in Tibet
2900 (916 in India)
194413 (58000 in India)
Dibang, Lohit, Subansiri, Manas, Teesta
Forms a large delta with Ganga in West Bengal; flows through Tibet (as Yarlung Tsangpo), Arunachal Pradesh (as Dihang) and Assam (as Brahmaputra); one of the largest rivers in terms of discharge and sediment load; prone to floods and erosion
Narmada
Amarkantak hills in Madhya Pradesh
1312
98796Banjar, Hiran, Tawa, BurhnerFlows through Madhya Pradesh and Gujarat; forms a rift valley with Vindhya and Satpura ranges; forms a large estuary near Bharuch; one of the westward flowing peninsular rivers; one of the most sacred rivers in Hinduism >TapiSatpura range in Madhya Pradesh724 >65145 >Purna, Girna, Panzara, Bori >Flows through Madhya Pradesh, Maharashtra and Gujarat; forms a rift valley with Satpura and Sahyadri ranges; forms a small estuary near Surat; one of the westward flowing peninsular rivers >GodavariNasik hills in Maharashtra1465 >312812 >
Flows through Maharashtra, Telangana, Chhattisgarh, Andhra Pradesh and Odisha; forms a large delta near Rajahmundry; one of the eastward flowing peninsular rivers; one of the longest rivers in India; known as the Dakshin Ganga or the South Ganga
Krishna
Mahabaleshwar hills in Maharashtra
1400
258948
Bhima, Tungabhadra, Ghataprabha, Malaprabha, Musi
Flows through Maharashtra, Karnataka, Telangana and Andhra Pradesh; forms a large delta near Vijayawada; one of the eastward flowing peninsular rivers; one of the largest rivers in terms of basin area; known for its irrigation potential and hydroelectric projects
Kaveri
Brahmagiri hills in Karnataka
765
81155
Hemavati, Kabini, Bhavani, Amravati, Noyyal
Flows through Karnataka and Tamil Nadu; forms a small delta near Thanjavur; one of the eastward flowing peninsular rivers; one of the most sacred rivers in Hinduism; known for its cultural and religious significance and inter-state water disputes
Drainage Basins of India
A drainage basin is an area of land that drains all the water to a common outlet such as a river, lake or sea. It is also called a catchment area or a river basin. A drainage basin has various features such as source, mouth, tributaries, distributaries, confluence, etc. A water divide is a highland or a ridge that separates one drainage basin from another. It can be continental or local.
India has four major drainage basins based on the direction and destination of the river flow. They are:
Himalayan rivers basin: This basin covers about 33% of the total land area of India. It drains the northern and northeastern parts of India. It includes the Indus, Ganga and Brahmaputra river systems and their tributaries. It drains into the Arabian Sea and the Bay of Bengal. It is characterized by large and perennial rivers, fertile floodplains, extensive deltas and estuaries.
Peninsular rivers basin: This basin covers about 43% of the total land area of India. It drains the central and southern parts of India. It includes the Narmada, Tapi, Godavari, Krishna and Kaveri river systems and their tributaries. It drains into the Arabian Sea and the Bay of Bengal. It is characterized by smaller and seasonal rivers, rocky and uneven terrain, narrow valleys and gorges.
Coastal rivers basin: This basin covers about 7% of the total land area of India. It drains the western and eastern coastal plains of India. It includes several short and swift rivers such as Mahanadi, Subarnarekha, Mahi, Sabarmati, Periyar, etc. It drains into the Arabian Sea and the Bay of Bengal. It is characterized by low discharge and sediment load, saline water intrusion and lagoons.
Inland drainage basin: This basin covers about 17% of the total land area of India. It drains the arid and semi-arid regions of western India such as Rajasthan and Gujarat. It includes several ephemeral streams such as Luni, Ghaggar, Banas, etc. It does not drain into any sea or ocean but ends up in salt lakes or marshes such as Sambhar lake or Rann of Kutch. It is characterized by high evaporation and salinity, low rainfall and vegetation.
Conclusion
In this article, we have learned about the drainage system of India and its various aspect