UPSC Prelims 2021 Q54: Didwana, Kuchaman, Sargol, Khatu — Explained
With reference to India, Didwana, Kuchaman, Sargol and Khatu are the names of
- glaciers
- mangrove areas
- Ramsar sites
- saline lakes
Answer: (d) saline lakes
Statement-wise explanation
- a: incorrect — Didwana, Kuchaman, Sargol and Khatu all lie in the hot, dry Thar–Aravalli region of Rajasthan, far from any snowfield. India's glaciers are in the Himalaya and Karakoram, for example Siachen, Gangotri and Zemu. No glacier exists in Rajasthan.
- b: incorrect — Mangroves are salt-tolerant trees of tidal coasts and estuaries, such as the Sundarbans, Bhitarkanika and the Gulf of Kachchh. These four places are inland in central Rajasthan, hundreds of kilometres from the sea, so no tidal mangrove forest can grow there.
- c: incorrect — Sambhar Lake, designated on 23 March 1990, is Rajasthan's Ramsar site in this salt-lake belt, along with Keoladeo National Park. Didwana, Kuchaman, Sargol and Khatu are not on India's Ramsar list. Option (c) works as a trap because these lakes sit near Sambhar.
- d: correct — All four are saline lakes, which are shallow salt playas in the inland-drainage zone of Rajasthan, north-west of Sambhar. Their streams never reach the sea, so the water evaporates and leaves salt behind. Didwana is a known source of salt and sodium sulphate, and its salt is low-grade and used mainly in industry.
How to eliminate
Location alone removes two options. All four places are in the dry interior of Rajasthan, so glaciers (Himalaya) and mangroves (tidal coasts) are both impossible. That leaves Ramsar sites or saline lakes. Remember that Rajasthan has only two Ramsar sites, Sambhar and Keoladeo, and none of these four names is a Ramsar site. Also, a Ramsar site is a legal designation, and UPSC rarely gives four obscure Ramsar sites from one small area. A natural feature they all share is more likely. If 'Didwana' or 'Kuchaman' reminds you of salt, which is often called 'Didwana salt', the answer follows. The fact to remember: Sambhar, Didwana, Kuchaman, Sargol, Khatu, Pachpadra and Lunkaransar are the saline lakes of Rajasthan.
Know more
Why Rajasthan has salt lakes
West of the Aravallis, much of Rajasthan has inland (interior) drainage. Seasonal streams flow into closed hollows instead of reaching the sea. In this hot, dry climate the water evaporates and the dissolved salts are left behind. Over time these hollows become playas: flat-floored, shallow lakes that swell after rain and dry into salt crusts in summer. The salt comes from weathering of the catchment rocks, carried in by floodwater.
Major saline lakes of Rajasthan
| Lake | Notes |
|---|---|
| Sambhar | India's largest inland salt lake, about 230 sq km. Ramsar site since 1990. Major salt producer; flamingo wintering ground |
| Didwana | Low-grade salt used in industry; sodium sulphate works |
| Kuchaman, Sargol, Khatu | Smaller playas in the same belt north-west of Sambhar |
| Pachpadra | Western Rajasthan; high-purity salt, about 98% NaCl |
| Lunkaransar | Bikaner region; small salt output |
Saline vs freshwater lakes of Rajasthan
Pushkar, Jaisamand, Rajsamand, Pichola and Fateh Sagar are freshwater lakes. Most are man-made or fed by the Aravallis, and they lie mainly east and south of the range. The saline lakes lie in the dry interior. When you see a list of Rajasthan lakes, sort them by this east/west split.
Related ideas UPSC links to this
- Centripetal drainage: streams flowing inward into a central depression, as at Sambhar.
- Luni: the main river of the region. Its water is brackish downstream of Balotra, and it ends in the Rann of Kachchh without reaching the sea as a normal river.
- Ramsar sites: Rajasthan has two, Sambhar and Keoladeo. Know which salt lake is a Ramsar site and which are not.
NCERT Concepts to Revise
- Sambhar Lake: Sambhar is the best-known lake of the same Rajasthan belt as Didwana and Kuchaman, so it anchors the answer.
- Inland drainage: Streams in this part of Rajasthan never reach the sea; that drainage type decides what kind of water body forms.
- Ramsar sites of India: One option is Ramsar sites; knowing which Rajasthan wetlands are actually listed helps you test it.