Topography and wind play an important role in the distribution of precipitation. The terms Ghats is derived from Hindi which means “river landing stairs” or “mountain pass”. 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. Before moving on to the discussion, firstly know that “What are Western Ghats and Eastern Ghats?”
It 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.
It is 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.
The reason why do the Western Ghats receive more rain than the Eastern Ghats are discussed below:
1. The winds from Arabian Sea climb the slopes of the Western Ghats from 900-1200 m. Soon, they become cool, and as a result, the windward side of the Western Ghats receive very heavy rainfall ranging between 250 cm and 400 cm. After crossing the Western Ghats, these winds descend and get heated up. This reduces humidity in the winds. As a result, these winds cause little rainfall in the Eastern Ghats.
2. The Western Ghats block rain-bearing winds which cause rainfall on the western slopes. Whereas South-west monsoon moves parallel to the Eastern Ghats, which cause less rainfall because in the Eastern Ghats unable to block moisture-laden winds.
3. The Western Ghats lies in rain-fed area of the Arabian Sea branch of the south-west monsoon whereas Eastern Ghats lies in the rain shadow area of the Arabian Sea branch of the south-west monsoon.
4. The Western Ghats have gentle slope that provides a greater area for sunlight absorption whereas the Eastern Ghats have an abrupt slope.