🔷 Introduction to Drainage System of India
- The term Drainage refers to the river system of an area.
- A drainage basin is the area drained by a single river system.
- A watershed is the boundary separating two drainage basins.
- Drainage patterns are determined by slope, rock structure, and climatic conditions.
- India’s diverse topography and climate influence the flow, direction, and volume of rivers.
- Rivers play a key role in agriculture, transportation, water supply, hydropower, and ecosystem balance.
🔷 Major Drainage Systems of India
✔️ Broadly classified into two major river systems:
- Himalayan Rivers
- Peninsular Rivers
✅ Himalayan Rivers
- These are perennial rivers – they flow throughout the year.
- Fed by melting snow and monsoon rains.
- Originates in the Himalayas and forms large basins.
- Exhibit youthful features like gorges, V-shaped valleys, waterfalls, and rapids.
- Known for meandering in the plains and forming ox-bow lakes and floodplains.
🔹 Major Himalayan Rivers:
- The Indus River System
- The Ganga River System
- The Brahmaputra River System
🔸 The Indus River System
- Originates near Lake Mansarovar in Tibet.
- Enters India in Jammu & Kashmir.
- Total length: 2,900 km (largest basin in terms of area).
- Major tributaries:
- Jhelum
- Chenab
- Ravi
- Beas
- Sutlej
- Flows through Pakistan, forming the Indus Water System.
- Governed by the Indus Water Treaty (1960) between India and Pakistan.
🔸 The Ganga River System
- Originates from Gangotri Glacier as Bhagirathi in Uttarakhand.
- Joins Alaknanda at Devprayag to form Ganga.
- Length: 2,500 km (longest river in India).
- Major tributaries:
- Right bank: Yamuna, Son
- Left bank: Ghaghara, Gandak, Kosi
- Flows through Uttar Pradesh, Bihar, West Bengal, and merges into the Bay of Bengal.
- Forms the Sundarbans Delta, the largest delta in the world.
🔸 The Brahmaputra River System
- Originates from Tibet as Tsangpo River.
- Enters India through Arunachal Pradesh as Dihang.
- Becomes Brahmaputra in Assam.
- Flows into Bangladesh, merges with Ganga, and forms Meghna River.
- Highly prone to flooding and siltation due to high sediment load.
- Used for navigation, irrigation, and hydropower generation.
✅ Peninsular Rivers
- Mostly seasonal rivers – dependent on monsoon rainfall.
- Flow through older, stable landmass – the Peninsular Plateau.
- Rivers have fixed courses, no meandering, and broad valleys.
- Less erosion and sediment transport compared to Himalayan rivers.
🔹 Major Peninsular Rivers:
- The Narmada River
- The Tapi River
- The Mahanadi River
- The Godavari River
- The Krishna River
- The Kaveri River
🔸 The Narmada River
- Origin: Amarkantak Plateau, Madhya Pradesh
- Flows westward into the Arabian Sea
- Forms beautiful gorges in Marble Rocks near Jabalpur
- Major west-flowing river of Peninsular India
- Forms estuary, not a delta
🔸 The Tapi River
- Origin: Satpura ranges, Madhya Pradesh
- Flows westward into Arabian Sea
- Shorter than Narmada
- Used for irrigation and hydroelectricity
🔸 The Mahanadi River
- Origin: Chhattisgarh
- Flows through Odisha, enters Bay of Bengal
- Forms fertile delta suitable for rice cultivation
- Known for flooding, controlled by Hirakud Dam
🔸 The Godavari River
- Also called Dakshin Ganga (Ganga of the South)
- Originates in Nashik, Maharashtra
- Longest Peninsular River (1,465 km)
- Tributaries: Purna, Wardha, Pranhita, Manjira, Indravati, Sabari
- Forms a large delta in Andhra Pradesh
🔸 The Krishna River
- Origin: Mahabaleshwar, Maharashtra
- Flows through Karnataka and Andhra Pradesh
- Tributaries: Bhima, Tungabhadra, Musi
- Supports agriculture and multipurpose river valley projects
🔸 The Kaveri River
- Origin: Talakaveri, Karnataka
- Flows through Tamil Nadu
- Forms fertile delta in the Bay of Bengal
- Known as lifeline of Tamil Nadu
- Major tributaries: Hemavati, Amravati, Kabini
🔷 Drainage Patterns in India
- Dendritic Pattern – Tree-like shape, common in Ganga system
- Radial Pattern – Rivers flow outward from a central point (e.g., Amarkantak Plateau)
- Trellis Pattern – Rivers and tributaries form a rectangular pattern
- Centripetal Pattern – Rivers flow inward into a basin (e.g., in Rajasthan)
🔷 Lakes in India
- Freshwater Lakes – Formed by glaciers, tectonic activity
- Wular Lake, Dal Lake, Nainital, Bhimtal
- Saltwater Lakes – Found in arid regions
- Sambhar Lake (Rajasthan) – largest inland saltwater lake
- Lakes help in moderating climate, recreation, fishing, and water supply
🔷 Role of Rivers in Economy
- Provide water for irrigation and drinking
- Used in hydroelectric power generation
- Enable inland navigation and transport
- Rivers support agriculture, industry, and fisheries
- Cultural significance – many rivers are sacred in Hinduism
🔷 River Pollution and Conservation
- Rivers in India face severe pollution from:
- Industrial waste
- Domestic sewage
- Religious offerings
- Plastic and chemical dumping
- Consequences:
- Ecosystem degradation
- Waterborne diseases
- Loss of aquatic biodiversity
- Government Initiatives:
- Namami Gange Programme – cleaning Ganga
- National River Conservation Plan (NRCP)
- Promoting public awareness and participation
🔷 Interlinking of Rivers
- Concept of linking rivers to manage floods and droughts.
- Ken-Betwa Project – first step toward river interlinking.
- Pros:
- Equal distribution of water
- Boost to agriculture and economy
- Cons:
- Displacement of people
- Ecological imbalance
- High cost of implementation
🔷 Important Facts & Figures
- Longest river in India: Ganga (2,500 km)
- Largest river basin: Ganga Basin
- Largest delta: Sundarbans Delta
- West-flowing rivers: Narmada, Tapi, Mahi
- Major rivers flowing into Arabian Sea: Narmada, Tapi
- River with highest sediment load: Brahmaputra
- Only river flowing in Rajasthan: Luni River
🔷 Conclusion
- India’s drainage system reflects the diverse geographical and climatic features of the country.
- Both Himalayan and Peninsular rivers play an essential role in shaping the physical and economic landscape.
- Sustainable management of rivers is vital for future generations.
- River conservation, pollution control, and judicious use of water resources are the key priorities.