Distribution of Rainfall in India

The distribution of rainfall in India is highly uneven, with some regions receiving heavy rainfall while others experience scarcity. This uneven distribution can be attributed to various factors, including:

1. Geographical Factors:
- Coastal Areas: Coastal regions such as the Western Ghats and the northeastern states receive heavy rainfall due to their proximity to the sea. The moist winds from the Arabian Sea and Bay of Bengal bring abundant moisture, causing heavy rainfall in these areas.
- Mountain Ranges: Mountain ranges like the Western Ghats and the Himalayas act as barriers for the moisture-laden winds. As the winds ascend the slopes, they cool down, leading to condensation and precipitation. This results in higher rainfall on the windward side of the mountains, while the leeward side experiences a rain shadow effect, causing less rainfall.

2. Monsoon Winds:
- Southwest Monsoon: India experiences a monsoon climate, with the southwest monsoon being the primary source of rainfall. The monsoon winds blow from the Arabian Sea and Bay of Bengal, bringing moisture-laden clouds to different parts of the country. However, the arrival, duration, and intensity of the monsoon vary from region to region, leading to an uneven distribution of rainfall.
- Retreating Monsoon: The retreating monsoon, also known as the northeast monsoon, affects the southeastern coast of India. This period accounts for a significant portion of the annual rainfall in these regions.

3. Topography:
- Plains: Coastal plains and river valleys are more likely to receive higher rainfall due to their low-lying nature, which facilitates the accumulation of moisture-laden clouds.
- Plateaus: Plateaus like the Deccan Plateau have relatively lower rainfall due to their higher elevation and lack of significant water bodies. The plateau acts as a barrier to the monsoon winds, causing them to lose moisture before reaching these regions.

4. Distance from the Equator:
- Regions closer to the equator, such as the southern states, receive more rainfall compared to areas farther north. This is because the equator receives more direct sunlight, leading to higher evaporation rates and the formation of more moisture-laden clouds.

5. El Niño and La Niña:
- The El Niño-Southern Oscillation (ENSO) phenomenon can impact the distribution of rainfall in India. During El Niño, the sea surface temperatures in the Pacific Ocean rise, leading to a weakening of the monsoon winds. This results in reduced rainfall in many parts of India. Conversely, during La Niña, the sea surface temperatures decrease, strengthening the monsoon winds and causing increased rainfall.

In conclusion, the uneven distribution of rainfall in India is influenced by factors such as geographical features, monsoon winds, topography, distance from the equator, and the occurrence of El Niño and La Niña events. These factors combine to create diverse climatic conditions across the country, resulting in varying levels of rainfall in different regions.