The correct option is (a).
Explanation
Rainfall variability refers to the degree of fluctuation in the amount of rainfall received from the long-term average. In the context of the Indian Monsoon, there is a distinct inverse relationship between the total amount of annual rainfall and its variability (measured by the Coefficient of Variation).
Statement-wise Analysis:
- Statement 1 is Correct: The Indian Monsoon is inherently pulsating and unreliable. Consequently, annual rainfall is highly variable from year to year, influenced by global climatic phenomena such as the El Niño-Southern Oscillation (ENSO) and the Indian Ocean Dipole (IOD).
- Statement 2 is Incorrect: Variability is highest in regions of low rainfall. For instance, regions like Western Rajasthan and the interior Deccan plateau, which receive low rainfall, exhibit very high variability (often exceeding 50%). Conversely, regions with high rainfall, such as the Western Ghats and the North-East, show the lowest variability.
- Statement 3 is Incorrect: Areas of high rainfall are generally reliable and are more liable to be affected by floods rather than droughts. It is the areas of low rainfall (with high variability) that are chronically liable to be affected by droughts, as even a minor deviation in scanty rainfall causes severe distress.
Key Takeaway:
Rainfall variability in India is inversely proportional to the quantity of rainfall. High rainfall areas have high reliability (low variability), while low rainfall areas have low reliability (high variability) and are drought-prone.