RAS question
'Reg' in desert geography means:
Correct answer: (D) Rocky desert/stony waste.
In desert geography, a reg is a rocky or stony desert surface, not a sand sea or sandy desert.
Explanation
Reg refers to a rocky or stony desert surface from which loose sand has been blown away, leaving stones and gravel behind. Britannica supports this meaning by describing regs, also called gibber plains, as stony plains with surfaces covered by coarse gravel and stones. That is why option D is correct: the defining feature is the exposed stony waste or desert pavement, not loose sand. In Rajasthan geography, this matters because parts of the Thar include such rocky or gravelly desert surfaces along with sandy forms. The word therefore identifies a surface type within arid landforms, not the desert as a whole.
Why the other options are wrong
- (A) A sand sea is an erg, where the dominant surface is extensive loose sand, while reg denotes a stony or gravelly desert surface.
- (B) A clay desert is a different arid-land surface; reg is identified by exposed stones and gravel after sand has been removed.
- (C) A sandy desert again points to an erg-like sand-dominated surface, whereas reg is rocky or stony waste.
Concept
This tests desert landform terminology in Rajasthan geography, especially the distinction between sandy and stony arid surfaces. It recurs in RAS because the Thar is studied through its specific geomorphic forms, not just as a generic desert.