Module 2: Winter, climate classification and agro-climatic zones
Concept
Subtopic 2.1: Winter, climate classification and agro-climatic zones
- Retreat of Monsoon: by mid-October the plains have received sufficient rain; the monsoon weakens and the wind reverses direction slowly.
- Cold dry westerly winds start, called 'Pachhua' (Bayar), a sign of the arrival of winter.
- Winter begins after mid-October. In November temperature is 19.6°C to 22.2°C; January average minimum is 7.5°C to 10.5°C.
- Cyclonic storms from the Mediterranean in December–January bring heavy rain, making it colder, and the rain is beneficial to the rabi crop.
- Köppen: north Bihar CWg, south AW. Thornthwaite: most of Bihar CA′W, the northern narrow area CB′W. Trewartha: about half the north CA′W, half the south AW.
- Agro-climatic zones (4): (1) North-west plain (W. Champaran, E. Champaran, Siwan, Saran, Muzaffarpur, Vaishali, Sitamarhi, Madhubani, Sheohar, Darbhanga, Samastipur, Gopalganj); (2) East plain (Purnia, Katihar, Saharsa, Madhepura, Supaul, Begusarai, Munger, Khagaria, Bhagalpur, Araria, Kishanganj); (3) South-west plain (Gaya, Nawada, Aurangabad, Jehanabad, Arwal, Patna, Nalanda, Rohtas, Bhojpur, Buxar); (4) Southern plateau (Banka, Jamui, Kaimur, Lakhisarai, Sheikhpura).
- Climate regions (4): NW foothill region, NE region, western low plateau of Rohtas and central region. The north-west foothills get over 1,400 mm of rain.
- Pachhua marks winter's arrival.
- November: 19.6 to 22.2°C.
- It helps the rabi crop.
- North: CWg; South: AW.
- Four zones.
- Rohtas belongs to the south-west plain zone; Banka to the southern plateau.
- Question: The cold dry westerly wind of winter is called: Answer: Pachhua (Bayar).
- Question: Average temperature range in November is: Answer: 19.6–22.2°C.
- Question: Winter rain brought by cyclonic storms is useful for: Answer: Rabi crops.
- Question: Köppen placed north Bihar and south Bihar in respectively: Answer: CWg and AW.
- Question: Number of agro-climatic zones in Bihar: Answer: 4.
- Question: Which district falls in the south-west plain zone? Answer: Rohtas.
MCQs
Answer this question, then use Next.
Question 1: The cold dry westerly wind of winter is called:
Question 2: Average temperature range in November is:
Question 3: Winter rain brought by cyclonic storms is useful for:
Question 4: Köppen placed north Bihar and south Bihar in respectively:
Question 5: Number of agro-climatic zones in Bihar:
Question 6: Which district falls in the south-west plain zone?
One-liners
Write your answer, then submit to see the correct answer.
The cold dry westerly wind of winter is called:
Pachhua (Bayar).Average temperature range in November is:
19.6–22.2°C.Winter rain brought by cyclonic storms is useful for:
Rabi crops.Köppen placed north Bihar and south Bihar in respectively:
CWg and AW.Number of agro-climatic zones in Bihar:
4.Which district falls in the south-west plain zone?
Rohtas.