Question

Which of the following are the reasons for Tamilnadu remaining dry during the period of South west monsoon?

1. The Eastern ghats and Tamilnadu coast are almost parallel to the direction of southwest monsoon.


2. Tropical cyclones disturb the pattern of south west monsoon.

3. Tamilnadu lies in the rain-shadow area of the Western Ghats.


Select the correct option using the options given below :-
(a) 1 and 2 only
(b) 1 only
(c) 1 and 3 only
(d) 2 and 3 only​

Answer 1

Option C - 1 and 3 Only

• Statement 2 is incorrect :- Disturbance due to tropical cyclones in the pattern of south west monsoon along Tamilnadu coast is not the factor for Tamilnadu remaining dry during the period of South west monsoon.

■ Explanation :-

• The monsoon approaches the landmass in two branches :-

The Arabian Sea branch :- The monsoon winds originating over the Arabian Sea further split into three branches :-

• Its one branch is obstructed by the Western Ghats. The windward side of the Sahyadris and Western Coastal Plain receive very heavy rainfall ranging between 250 cm and 400 cm.

• Another branch of the Arabian Sea monsoon strikes the coast north of Mumbai. Moving along the Narmada and Tapi River valleys, these winds cause rainfall in extensive areas of central India. The Chotanagpur plateau gets 15 cm rainfall from this part of the branch. Thereafter, they enter the Ganga plains and mingle with the Bay of Bengal branch.

• A third branch of this monsoon wind strikes the Saurashtra Peninsula and the Kachch. It then passes over west Rajasthan and along the Aravalis, causing only a scanty rainfall. In Punjab and Haryana, it too joins the Bay of Bengal branch. These two branches, reinforced by each other, cause rains in the western Himalayas.

The Bay of Bengal branch :-

• The Bay of Bengal branch strikes the coast of Myanmar and part of southeast Bangladesh. But the Arakan Hills along the coast of Myanmar deflect a big portion of this branch towards the Indian subcontinent.

• The monsoon, therefore, enters West Bengal and Bangladesh from south and southeast instead of from the south-westerly direction.

• From here, this branch splits into two under the influence of the Himalayas and the thermal low is northwest India. Its one branch moves westward along the Ganga plains reaching as far as the Punjab plains. The other branch moves up the Brahmaputra valley in the north and the northeast, causing widespread rains.

Reasons for Tamil Nadu coast remaining dry during this season :-

• The Tamil Nadu coast is situated parallel to the Bay of Bengal branch of southwest monsoon.

• It lies in the rain-shadow area of the Arabian Sea branch of the south-west monsoon.

Hope It helps you