Question

How do the western disturbances affect the crops in India?
A)They cause heavy damage to the standing crops.
B)They bring in locus which destroy the crops.
C)They are beneficial to the crops by causing winter rain.
D)They help in keeping the plants warm to some extent in winter.

Answer 1

Hint: 1)Western disturbances arise in the Mediterranean.
2)Western Disturbances bring heavy snowfall to the Himalayas and also cold waves to the northern Indian plains.
3)Western disturbances impact the weather during the winter season up to Patna.

Complete answer:
Western disturbance is an extratropical storm that brings sudden winter rain to the northwestern part of the Indian subcontinent. It's a non-monsoon precipitation pattern driven by the West. Moisture in these storms typically originates in the Mediterranean Sea, the Caspian Sea and the Black Sea.
Western disturbances, especially those in winter, bring moderate to heavy rain in the low-lying areas of the nation as well as heavy snow to the mountainous areas of the Indian Subcontinent.

They are the source of most of the winter and post-monsoon rainfall in northwest India. Precipitation during the winter season is of great relevance in agriculture especially for the rabi crops. Wheat is one of the most important crops to help meet India's food security needs. Average of four to five western disturbances occur during the winter season. The distribution and amount of rainfall varies with each western disturbance.

Western disturbances are typically associated with cloudy skies, higher night temperatures and unusual rainfall. Excessive precipitation due to Western disturbances can cause crop damage, landslides, floods and avalanches. On the Indo-Gangetic plains, often cold waves and thick fog occur. These conditions remain stable until more western disruptions have been disrupted. As Western disturbances pass through northwest India prior to the start of the monsoon, a temporary increase in monsoon current occurs across the area.
Following are the given options:

1)The western disturbances do not cause heavy damage to the standing crops. Thus, Option A is incorrect.
2)The western disturbances do not bring in locusts which destroy the crops. Thus, Option B is also incorrect.
3)The western disturbances are beneficial to the crops by causing winter rain. Thus, Option C is correct.
4)The western disturbances do not help in keeping the plants warm to some extent in winter. Thus, Option D is incorrect

Hence, the correct answer is option (C)

Note: 1)The strongest western disturbances normally occur in the northern part of Pakistan, where floods are recorded several times during the winter season.
2)The interaction of the monsoon trough with western disturbances can sometimes cause dense clouds and heavy precipitation. The result of one such encounter is said to be the 2013 North India floods, which killed more than 5,000 people in 3 days.
3)Western disturbances tend to decrease in numbers after the winter.