Structure:

Introduction: (upto 30 words) Start by explaining rainfall due to Monsoon winds is a form of Orographic rain.

Body: (upto 100 words) Bring outreasons why there is more rainfall along WG and less along EG and variations along them.

Conclusion: (upto 30 words) Conclude by pointing out that WG receives surplus rain whereas EG receives deficit rain. Therefore there is a need for water management.

Supporting Points:

Topography and wind play an important role in the distribution of precipitation. The Ghats, which mean Western and Eastern Ghats, are two mountain ranges forming the eastern and western edges, respectively, of the Deccan plateau of peninsular India.  The rain received is due to Orographic reasons. Monsoonal winds, coming from Indian Ocean, bifurcates into Arabian and Bay of Bengal branch after clashing with Nilgiri range.

WG extends from the mount of the river Tapi to the Cape of Kanyakumari for a distance of 1600 km. Its average height is 1200 m. It is not a real hill range; rather it is a rift side of the peninsular plateau. The height of the Western Ghats increases from North to South. Nilgiris Hills, Annamalai Hills, and Cardamom Hills are major hills.

EG located along the east coast in Tamil Nadu, Andhra Pradesh and Odisha. The average height of the Eastern Ghats is 600m. Stanley Shevaroy Hills, Javadi Hills, Palkonda Range and Nallamala Hills are major hills.

Western Ghats related:

1. The Arabian branch that enters through Western Ghats make much larger part of the monsoon than that through Eastern side. The Monsoonal Winds move perpendicular to the Western Ghats.
2. First, the mountain topography in Karnataka is broader than the narrow topography of the Ghats in Maharashtra. Due to the greater width of the mountains, the rain bearing winds have to necessarily travel a longer distance and have more time for the drops to coalesce and precipitate as rainfall, resulting in higher rainfall. In contrast, the narrow width of the Ghats in Maharashtra allows the rain-bearing wind to cross over to the leeward side rapidly before precipitation can occur. As for Kerala, the Ghats there are in the form of isolated mountains, where the rain-bearing winds can easily cross over to the leeward side through the gaps in between without precipitation occurring.
3. Second, the slope of the mountain has a direct bearing on the possibility of precipitation. This is borne out by the Ghats of Karnataka where the mountains are gently sloping, compared to the steep slopes of the Ghats in Maharashtra and Kerala. The air parcel will retain its energy and speed for a longer time when the slope is gradual. This will provide sufficient vertical motion to cloud droplets to grow by collision–coalescence process and hence form precipitation.
4. Third, the gentle slope provides a greater area for sunlight absorption and heating leading to greater convection when compared with an abrupt slope i.e. less Ghat area such as that of the Maharashtra and Kerala Ghats.
5. Height of Western Ghats: The average height of Western Ghats is around 1500 metre while the for Eastern Ghats, it is around 900 metre. Thus, Western Ghats successfully blocks wind and causes precipitation.
6. The expansion of Western Ghats: The Western Ghats is broader than Eastern Ghats especially in Karnataka. It makes conducive situation to extended rainfall.

Eastern Ghats related:

1. The direction of Eastern Ghats: Eastern Ghats runs parallel to the direction of south-west monsoon, thus unable to block and get precipitated.
2. The distance: The Arabian branch winds get dried till it reach Eastern coast at some places.
3. The Eastern Ghats not being continuous in nature is not able to successfully block the Bay of Bengal Branch of SW Monsoon Winds.
4. The Bay of Bengal Branch of SW Monsoon Winds is weaker than the Arabian Sea Branch and hence carries less moisture
5. The Eastern Ghats receive most of their rainfall from the retreating monsoon, but it carries lesser moisture in comparison to the south west monsoon.