Why are the western stopes of the Western Ghats covered with thick forests and not the eastern slopes

Western slopes of Western Ghats are covered with thick forests and not eastern slopes because western slopes lie in windward side and receive heavy rainfall as compared to Eastern Ghats which lie in a rainshadow region. It happens in this way:

As the summer (wet) monsoons approach the west coast of India, they rise up the western Ghats (mountains) and the air cools. This cool air is less able to hold moisture and it is released as rainfall. Giving a form of rainfall called OROGRAPHIC RAINFALL . Orographic means that it is related to mountains. By the time the winds make it over the Western Ghats they have lost most of their moisture and very little falls on the Deccan Plateau to the east of the ghats. This reduced rainfall on the leeward side (away from the wind) of mountains is called a RAIN SHADOW EFFECT.