Consider the following sources of world water supply and arrange them in descending order.
1. Oceans
2. Rivers
3. Polar ice and Glaciers
4. Ground water
Select the correct answer from the code given b

Question

Consider the following sources of world water supply and arrange them in descending order.
1. Oceans
2. Rivers
3. Polar ice and Glaciers
4. Ground water
Select the correct answer from the code given below :

UnlockIAS · Accepted Answer

Correct — A, 1, 3, 4, 2 — that is Oceans, then Polar ice and Glaciers, then Ground water, then Rivers. The oceans dominate the hydrosphere so completely that nothing else is close: about 1,338 million cubic kilometres of water, roughly 96.5 per cent of all the water on Earth. Ice caps, glaciers and permanent snow come second at about 24.4 million cubic km (about 1.76 per cent), and groundwater follows very closely at about 23.4 million cubic km (about 1.69 per cent) — a gap of well under a tenth of a percentage point, which is precisely what makes this a testable ordering. Rivers finish last and are not in the same league as anything above them: all the water flowing in the world's river channels at any given moment adds up to only about 2,120 cubic km, roughly 0.0002 per cent of the global total. So the descending sequence is 1, 3, 4, 2.

Why the other options are wrong — (b) This puts Rivers second, immediately after the oceans. Rivers are in fact the smallest of the four stores by a huge margin — about 2,120 cubic km against roughly 24 million cubic km in ice and 23 million cubic km in groundwater. River water is small in volume precisely because it is fast-moving: it is the flow that matters, not the standing stock.  (c) Wrong at both ends of the sequence. It again promotes Rivers to second place, and it pushes Polar ice and Glaciers down to last — yet ice and snow are the single largest store of water after the oceans and hold roughly 68 per cent of all the fresh water on Earth.  (d) The near-miss, and the option most candidates lose the mark to. It gets the first and last places right but swaps the middle two, placing Ground water above Polar ice and Glaciers. The volumes are genuinely close (about 1.69 per cent versus about 1.76 per cent of all water), but ice still edges ahead — and the margin widens if you count only fresh water, where glaciers hold about 69 per cent against groundwater's roughly 30 per cent.

Concept: The hydrosphere holds roughly 1.386 billion cubic kilometres of water, and it is distributed with extreme unevenness. About 96.5 per cent sits in the oceans as salt water. Of the small remainder, most is not available to us: it is locked in polar ice caps, glaciers and permanent snow, or stored deep underground as groundwater (a large part of which is itself saline). Surface fresh water in lakes, rivers, swamps, soil moisture and the atmosphere together account for a tiny sliver of the total, and rivers — the water humans most obviously live off — are the smallest slice of all.

State PCS 2025 Q71 — Geography PYQ with Answer

State PCS 2025 Q71 — Geography PYQ with Answer