Which one of the following is the best example of repeated falls in sea level, giving rise to present-day extensive marshland?

(a) Bhitarkanika Mangroves
(b) Marakkanam Salt Pans
(c) Naupada Swamp
(d) Rann of Kutch ✓ UPSC's answer

Why the answer is (d)

• The Rann of Kutch in Gujarat was once a shallow arm of the Arabian Sea; repeated falls in sea level, silting by the Indus and Luni systems and tectonic uplift (notably after the 1819 earthquake) turned it into the vast salt marsh seen today.

• It floods in the monsoon and dries into a white salt crust in summer — the world's largest salt desert, with the Great and Little Rann covering about 30,000 sq km.

• Bhitarkanika is a river-delta mangrove swamp in Odisha, Marakkanam salt pans in Tamil Nadu are man-made evaporation ponds, and Naupada swamp in Andhra Pradesh is a coastal wetland — none is a product of marine regression on this scale.

• Hence option (d).

Why the other options are wrong

(a) Bhitarkanika Mangroves: Bhitarkanika is a deltaic mangrove swamp, not a product of sea-level fall.
(b) Marakkanam Salt Pans: Marakkanam salt pans are artificial evaporation ponds.
(c) Naupada Swamp: Naupada is a coastal wetland, not a marine-regression marsh.

Asked in the GS Paper I of the UPSC Civil Services Preliminary Examination 2023, held on 28 May 2023. Question and answer key: Union Public Service Commission. Explanation: UPSC Answer Check.