Understanding Koppen's Climate Classification in Rajasthan

Koppen's climate classification system is a widely used system for classifying the world's climates based on vegetation, temperature, and precipitation patterns. In Rajasthan, India, different parts of the state fall under various Koppen climate types due to its diverse geography and climate.

The major Koppen climate regions found in Rajasthan include:

• Aw (Tropical Humid or Savanna): Characterized by a hot, wet summer and a dry winter. Found in the southern parts of Rajasthan.
• BWhw (Hot Desert): Very arid with high temperatures and very low rainfall. Found in the extreme western parts of Rajasthan.
• BShw (Semi-arid Steppe): Transitional climate between desert and more humid climates, with low rainfall but enough to support sparse grassland. Covers a large part of western and central Rajasthan.
• Cwg (Humid Subtropical): Characterized by a hot, dry summer and a mild winter with some rainfall, mainly during the monsoon. Found in eastern and southeastern parts of Rajasthan.

Analyzing the Given Pairs of Climate Region and District

Let's examine each pair provided in the options:

• (A) Aw - Banswara: Banswara is located in the southern part of Rajasthan, which is known to fall under the Aw (Tropical Humid) climate region according to Koppen's classification. This pair is generally considered a correct match.
• (B) BWhw - Barmer: Barmer district is located in western Rajasthan. While parts of western Barmer are very arid and border the Hot Desert (BWhw) region, a significant portion and often the majority of Barmer district are classified under the BShw (Semi-arid Steppe) climate. Districts like Jaisalmer are more centrally located within the BWhw climate region. Therefore, pairing Barmer predominantly with BWhw might be considered an incorrect match compared to other districts.
• (C) BShw - Pali: Pali district is located in central/western Rajasthan. This region falls under the BShw (Semi-arid Steppe) climate, which is characterized by less aridity than the true desert but still receives low rainfall. This pair is generally considered a correct match.
• (D) Cwg - Tonk: Tonk district is located in eastern Rajasthan. This area typically falls under the Cwg (Humid Subtropical) climate, experiencing a hot, dry summer followed by monsoon rains. This pair is generally considered a correct match.

Based on the typical distribution of Koppen's climate types in Rajasthan, the pairing where a district is incorrectly matched with its predominant climate region is often considered to be BWhw with Barmer, as Barmer lies more extensively in the BShw region compared to being a core BWhw district like Jaisalmer.

Therefore, the pair that is not a correct match is (B) BWhw - Barmer.