RAS question
Alluvial soils in Rajasthan are primarily found in which region?
Correct answer: (C) Eastern Plains (Alwar-Bharatpur-Dholpur-Karauli).
Alluvial soils in Rajasthan are primarily found in the Eastern Plains, especially the Alwar-Bharatpur-Dholpur-Karauli belt.
Explanation
Alluvial soils belong to Rajasthan's eastern plains rather than its hills, desert or basaltic plateau zones. They occur in the Alwar-Bharatpur-Dholpur-Karauli belt, where rivers such as the Chambal, Banas and their tributaries have deposited old alluvium, or bangar, and new alluvium, or khadar. Rajasthan State Biodiversity Board supports this regional logic: after describing the Thar in the west and the Kota-Bundi tableland in the southeast, the Board notes that farther north the land levels out and the flat plains of northeastern Bharatpur form part of an alluvial basin. That is why the Eastern Plains option best matches the soil type and its depositional setting.
Why the other options are wrong
- (A) Mount Abu hills are part of the Aravalli hill context and have thin rocky soil, so they do not represent Rajasthan's alluvial plains setting.
- (B) Hadoti Plateau, represented by Kota-Bundi, is a tableland and is associated with black cotton soil from basaltic origin, not the alluvial deposits of the eastern plains.
- (D) The Thar Desert around Jaisalmer-Barmer belongs to Rajasthan's sandy western tract, where sandy desert soil is primary rather than alluvial soil.
Concept
This tests the RAS Geography mapping of Rajasthan's soil regions to physiographic divisions. It recurs because many questions ask candidates to connect a soil type with the region, rivers and landform that explain its occurrence.