CORE Key Points at a Glance

  1. 1

    Two Broad Drainage Types

    • Himalayan rivers — perennial, glacier+snow fed, antecedent drainage
    • Peninsular rivers — seasonal/rain-fed, consequent drainage following plateau slopes
    • The two regimes are separated by the Indo-Gangetic trough
    • Classification is the foundation for all river questions in the exam
  2. 2

    Ganga — India's Longest River

    • Length: 2,525 km; drains the largest basin — 8.6 lakh sq km (26% of India)
    • Rises from Gangotri glacier (Gaumukh) at 3,892 m in Uttarakhand
    • India's national river (declared 2008)
    • Declared national river status: 2008; Namami Gange programme: ₹20,000 crore
  3. 3

    Indus — Longest in the System

    • Pakistan's national river, but originates in Tibet (near Mansarovar Lake)
    • Passes through Ladakh (India) before entering Pakistan; total length 3,180 km
    • India's share: ~1,114 km; regulated by Indus Waters Treaty (1960)
    • Indus Gorge depth: ~5,200 m — deeper than the Grand Canyon
  4. 4

    Brahmaputra — World Records

    • Originates as Tsangpo in Tibet; enters India through Arunachal Pradesh (Dibang Valley)
    • Flows 918 km in India before entering Bangladesh as Jamuna
    • Forms the world's largest river island — Majuli (880 sq km) in Assam
    • Annual discharge ~585 BCM — 3rd highest in Asia
  5. 5

    Antecedent Drainage and Himalayan Gorges

    • Himalayan rivers are older than the mountains — they cut through rising ranges
    • This creates spectacular gorges: Indus Gorge (5,200 m deep)
    • Brahmaputra's Yarlung Tsangpo Canyon: 5,382 m deep — world's deepest
    • Antecedent rivers: Indus, Sutlej, Brahmaputra
  6. 6

    Godavari — Dakshin Ganga

    • India's longest peninsular river: 1,465 km
    • Rises from Trimbakeshwar (Nashik, Maharashtra); called "Dakshin Ganga"
    • Drains 3.13 lakh sq km — 2nd largest peninsular basin
    • States covered: Maharashtra, Telangana, AP, Chhattisgarh, Odisha
  7. 7

    Krishna River — PYQ 2023 Focus

    • Length: 1,400 km; originates from Mahabaleshwar (Western Ghats, Maharashtra)
    • PYQ 2023 asked for 8 tributaries: Bhima, Tungabhadra, Malprabha, Ghataprabha, Koyna, Musi, Muneru, Yerla
    • Tungabhadra is the largest Krishna tributary; Hampi (UNESCO) is on its banks
    • Nagarjunasagar Dam on Krishna — one of India's largest dams
  8. 8

    Narmada and Tapi — West-Flowing Exceptions

    • Both flow westward into the Arabian Sea through rift valleys (grabens)
    • Unlike other peninsular rivers flowing east toward Bay of Bengal
    • Narmada: 1,312 km (originates Amarkantak, MP); no delta — forms estuary
    • Tapi: 724 km (originates Satpura range, MP; enters sea at Surat)
  9. 9

    Five Drainage Patterns in India

    • Dendritic — tree-like, most common; Ganga system, uniform substrate
    • Trellis — right-angle tributaries; Peninsular rivers crossing parallel ridges
    • Radial — rivers radiate from a central point; Amarkantak (Narmada, Son, Mahanadi)
    • Centripetal — flow toward a basin; Loktak Lake, Sambhar Lake
    • Parallel — rivers in plains; Punjab rivers (Ravi, Beas, Sutlej)
  10. 10

    Kaveri River — South India's Granary

    • Originates from Brahmagiri Hills (Kodagu, Karnataka) at 1,341 m; length 800 km
    • Major tributaries: Hemavati, Arkavati, Shimsha, Harangi, Kabini (left); Lakshmantirtha (right)
    • Forms Shivanasamudra Falls (98 m) — India's 2nd largest waterfall
    • Cauvery water dispute (Karnataka vs Tamil Nadu): SC final order February 2018
  11. 11

    Interlinking of Rivers (ILR) Project

    • National Perspective Plan: 30 river links (16 peninsular + 14 Himalayan)
    • Goal: transfer water from surplus basins to deficit regions
    • Estimated cost: ₹5.60 lakh crore
    • Ken-Betwa Link — first approved (2021); ₹44,605 crore; passes through Panna Tiger Reserve
  12. 12

    River Basin Coverage — Key Data

    • Ganga: 26% | Indus: 11.5% | Godavari: 9.5% | Krishna: 8%
    • Brahmaputra: 5.9% | Mahanadi: 4.3% | Narmada: 2.9%
    • Kaveri: 1.9% | Tapi: 1.6%
    • Total utilizable water in India: ~1,123 BCM out of 1,869 BCM annual discharge

PREDICTED Predicted RAS Questions

Based on PYQ trends and 2026 syllabus analysis

1 5M Name any eight tributaries of the Krishna River. 5 marks · 50 words

Model Answer

The Krishna River (1,400 km; originates Mahabaleshwar, Maharashtra) has these major tributaries: (1) Bhima (861 km, right); (2) Tungabhadra (right — Hampi); (3) Ghataprabha (right); (4) Malprabha (right); (5) Musi (right — flows through Hyderabad); (6) Koyna (left — Koyna Dam); (7) Yerla (left); (8) Muneru (left). Tungabhadra is its largest tributary.

~50 words • 5 marks