Question

Winter rainfall in Tamil Nadu is caused by __________.
A. North-east trade winds.
B. Depression over Arabian Sea.
C. Cold winds coming from Tibet
D. Western disturbances

Answer 1

Hint: The state receives three different periods of rainfall. One of the reasons is the direction of the air. The state has also been categorized into seven agro climatic zones.

Complete answer:
Option A – North-east trade winds is the main reason behind winter rainfall in Tamil Nadu. As the state is situated in the eastern coast of India, the southern portion of India receives rainfall from the Southwest monsoons which are obstructed by the Western Ghats. This leads to rainfall being received from Northeast as well as Retreating monsoons in the state. Also, it is identified that many low pressure systems have been developed in Bay of Bengal in this period which moves towards the east coastal region of Tamil Nadu leading to heavy rainfall.
The state has been classified into three different periods of rainfall namely – advanced rainfall, rainfall from the tropical cyclones which emerge in the Andaman Islands and the North-East monsoon which occur during the months of October-December. When compared to the total annual rainfall the Northeast monsoon contributes 48% of the total rainfall and the Southwest monsoon contributes 32% of the rainfall. The state is mainly dependent entirely on the rains for recharging its resources of water and failure in these monsoon can lead to acute scarcity as well as severe droughts.

Therefore, the correct answer is Option A.

Note:The seven categories of agro-climatic zones in which Tamil Nadu has been divided are:-
North-East
North-West
West
Southern
High Rainfall
High altitude
Cauvery Delta