Consider the following statements about a river : This river originates in the Hindu Kush mountain range and flows into Hamoun wetlands after covering a long stretch of about 1,100 km. There has been serious conflicts between two neighbouring nations regarding the sharing of water from this river. Identify the river from the following :
- (a)Mekong
- (b)Tarim
- (c)Indus
- (d)Helmand
Correct — D, Helmand. Every clue in the stem points to it. The Helmand rises in the Sanglakh range of the Hindu Kush in the north-eastern part of Maidan Wardak province in Afghanistan, about 40 km west of Kabul. It runs roughly 1,150 km, which is the long stretch the question rounds to about 1,100 km, and instead of reaching any sea it ends inland, feeding the Hamun lakes and marshes of the Sistan basin on the Afghanistan-Iran border. And it is the river over which two neighbours argue: its water is essential to farmers in Afghanistan and equally important to farmers in Iran's south-eastern Sistan and Baluchestan province, so how much water crosses the frontier is a standing quarrel between the two governments.
- (a)Mekong — The Mekong rises on the Tibetan plateau in China, not in the Hindu Kush, and runs about ten times the length given here through Myanmar, Laos, Thailand, Cambodia and Vietnam before reaching the sea. Its water disputes involve six riparian states, not two.
- (b)Tarim — The Tarim is an inland river of the Tarim basin in Xinjiang, in western China. It does share the Helmand's most distinctive feature — it never reaches an ocean — but it is entirely within one country, so there are no two neighbouring nations to quarrel over it, and it is nowhere near the Hamun wetlands.
- (c)Indus — The Indus is the answer a candidate reaches from the water-dispute clue alone, since India and Pakistan share it under the Indus Waters Treaty. But the Indus rises in Tibet, not the Hindu Kush, is far longer than 1,100 km, and ends in the Arabian Sea, not in an inland marsh.
The Helmand is Afghanistan's longest river and the lifeline of its arid south-west. Unlike most great rivers it is endorheic — it drains into an inland basin rather than to the sea, spreading out into the Hamun wetlands where Afghanistan meets Iran. That makes the whole basin unusually sensitive: whatever is stored or diverted upstream in Afghanistan shows up directly as less water in the Iranian Sistan, and in a dry year the wetlands themselves shrink.
Riddle questions like this one give three or four clues and expect you to use the one that eliminates fastest. Length and origin are the sharp clues here. The Hindu Kush is an Afghan and Pakistani range, so any river said to rise in it belongs to that neighbourhood, and about 1,100 km is far too short for the Mekong or the Indus. The terminus is the clinching detail: a river that ends in wetlands rather than in a sea is unusual, and the Hamun is the wetland the Helmand feeds. Note also what the stem does not say — it says conflicts between two neighbouring nations, which fits a bilateral basin, and only the Helmand among the four is a two-country river.
- The Helmand originates in the Sanglakh range of the Hindu Kush in Maidan Wardak province, roughly 40 km west of Kabul.
- It stretches about 1,150 km, and feeds the Hamun lakes on the Afghanistan-Iran border rather than reaching any sea.
- Its water is essential to farmers in Afghanistan and to farmers in Iran's Sistan and Baluchestan province, which is what makes its sharing contentious.
- The Mekong rises in China and empties into the sea after passing through six countries; the Indus rises in Tibet and reaches the Arabian Sea.
- Reading water dispute and answering Indus without checking origin, length or terminus.
- Assuming any long Asian river must reach an ocean; the Helmand and the Tarim do not.
- Confusing the Hindu Kush with the Karakoram or the Pamirs when placing a river's source.
Asked as an identify-the-river riddle in which origin, length, terminus and a dispute are handed over together and any one of them should settle it.
Consider the following pairs: River — Flows into 1. Mekong — Andaman Sea 2. Thames — Irish Sea 3. Volga — Caspian Sea 4. Zambezi — Indian Ocean Which of the pairs given above is/are correctly matched?
- (a) 1 and 2 only
- (b) 3 only
- (c) 3 and 4 only
- (d) 1, 2 and 4 only
Answer(c) 3 and 4 only
Exactly the fact this NDA riddle turns on — where a river ends. The Volga pair is right there because it too drains into an inland body of water, which is the Helmand's defining feature as well.
The great Asian river Mekong does not run through
- (a) China
- (b) Malaysia
- (c) Cambodia
- (d) Laos
Answer(b) Malaysia
Rules out the first option here. A river running through five or six countries cannot be the two-nation, 1,100 km river of this stem, and knowing the Mekong's course is what makes that obvious at a glance.
- practice — not a real PYQ
The Hamun wetlands, which receive the waters of the Helmand river, lie on the border of Afghanistan and
- (a)Iran
- (b)Turkmenistan
- (c)Uzbekistan
- (d)Pakistan
Answer(a) Iran — the wetlands sit in the Sistan basin, and the sharing of Helmand water is a long-running issue between Kabul and Tehran.
- practice — not a real PYQ
Which one of the following rivers does NOT drain into a sea or an ocean ?
- (a)Mekong
- (b)Indus
- (c)Helmand
- (d)Irrawaddy
Answer(c) Helmand — it ends in the inland Hamun lakes of the Sistan basin, an endorheic drainage.