Question

Which of the following statements are true about the variability of rainfall in India?

1. Variability is calculated using the formula: (Standard deviation / Mean) x 100.

2. Higher variability indicates more consistent rainfall patterns.

3. Variability contributes to the occurrence of droughts and floods.

4. The annual average rainfall of India is 250 cm.

• A. 1 & 3
• B. 2 & 4
• C. 1 & 4
• D. 2 & 3

Answer 1

Answer:

A. 1 & 3

• Variability is calculated using the formula: (Standard deviation / Mean) x 100. This is the correct statistical formula for the coefficient of variation, which is used to measure rainfall variability as a percentage.

• Higher variability actually indicates less consistent rainfall patterns, not more consistent ones. Higher variability means there are greater deviations from the mean rainfall, showing unpredictable or irregular patterns. Consistent rainfall would have low variability.

• Variability contributes to the occurrence of droughts and floods. When rainfall patterns are highly variable, some regions may experience excessive precipitation (causing floods) while others face deficient rainfall (causing droughts) during the same period.

• The annual average rainfall of India is approximately 118 cm (or about 1,170 mm), not 250 cm. The figure of 250 cm is an overestimation of the actual average rainfall received in India