India: relief, rivers & drainage

Answer: (c) 1, 3 and 4 only

Nagarhole, Sathyamangalam and Wayanad are all drained by the Kaveri (Cauvery) and its tributaries, but Papikonda National Park lies along the Godavari in Andhra Pradesh, so 2 is the only one that does not belong.

• ✓ 1. Nagarhole's own stream, the Nagarahole, joins the Kabini, and the Kabini is a right-bank tributary of the Kaveri.
• ✗ 2. Papikonda National Park is in the Papi Hills of Andhra Pradesh, where the Godavari cuts through the range; it belongs to the Godavari basin, not the Cauvery.
• ✓ 3. Sathyamangalam Tiger Reserve in Erode district (Tamil Nadu) is drained by the Bhavani, Moyar and Suvarnavathi, which are Kaveri tributaries.
• ✓ 4. Wayanad Wildlife Sanctuary in Kerala is drained by the Kabini, which rises in Wayanad and joins the Kaveri in Karnataka.

Remember · Nagarhole, Wayanad and Sathyamangalam sit in the Kabini-Bhavani part of the Cauvery basin; Papikonda sits on the Godavari.

Question and answer: UPSC's official GS Paper I (2020, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 1 Oct 2026 (how we verify). Permalink · Report an error

Answer: (d) North of Nubra Valley

Siachen Glacier lies in the eastern Karakoram range, up the Nubra Valley of Ladakh, so it is north of the Nubra Valley. It is not east of Leh, east of Aksai Chin or north of Gilgit.

• ✓ (d) The Nubra Valley runs up towards the Siachen Glacier, which sits at its head in the eastern Karakoram; the glacier is therefore north of the valley.
• ✗ (b) Siachen is north of Leh, across the Ladakh range and the Nubra and Shyok valleys, not to its east.
• ✗ (c) Gilgit lies to the west of the Karakoram range, so Siachen is south-east of Gilgit, not north of it.
• ✗ (a) Aksai Chin is on the plateau to the east of the Karakoram, so Siachen lies west of it.

Remember · Siachen Glacier: eastern Karakoram, at the head of the Nubra Valley, Ladakh; the Nubra River begins from its snout.

Question and answer: UPSC's official GS Paper I (2020, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). Permalink · Report an error

Answer: (b) 2 and 3 only

Why not the tempting option · UPSC's key is (b). Statement 1 looks plausible because 256 of India's roughly 720 districts (about 36%) were chosen as 'water stressed' for Jal Shakti Abhiyan in 2019, but those are districts holding at least one stressed block, picked by the Ministry for a campaign; the official 'overexploited' and 'critical' labels are given to blocks, not districts, by the Central Ground Water Board, not the Authority, and cover about 22% of blocks. In the exam, check the unit (block or district) and the body (CGWB assesses, CGWA regulates) before accepting a statistic.

Statements 2 and 3 are correct. CGWA was constituted in January 1997 under Section 3(3) of the Environment (Protection) Act, 1986, and India, the world's largest user of groundwater, has the largest groundwater-irrigated area. Statement 1 fails on every count: groundwater status is assessed for blocks (assessment units), not districts; the assessing body is the Central Ground Water Board, not the Authority; and the stressed share is nowhere near 36%.

• ✗ 1. The Central Ground Water Board, with the states, classifies assessment units — blocks, mandals, talukas — not districts, and the CGWA is a regulator, not the assessing body. In the 2017 assessment about 17% of units were overexploited and 5% critical, roughly 22% in all. The 36% figure resembles the 256 'water stressed' districts (of about 720) chosen for Jal Shakti Abhiyan in 2019 — districts holding at least one stressed block, a different count made by a different body.
• ✓ 2. On the direction of the Supreme Court, CGWA was constituted in January 1997 under sub-section (3) of Section 3 of the Environment (Protection) Act, 1986, to regulate groundwater development.
• ✓ 3. Groundwater provides about 60 per cent of India's irrigation water and over 80 per cent of its domestic supply, making India the world's largest user of groundwater. The area irrigated from it has grown to more than 35 million hectares — the largest groundwater-irrigated area of any country.

Remember · CGWA: set up January 1997 under Section 3(3), Environment (Protection) Act, 1986. India is the world's largest groundwater user; overexploited/critical labels apply to blocks (by CGWB), not districts.

Question and answer: UPSC's official GS Paper I (2020, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 1 Oct 2026 (how we verify). Permalink · Report an error