Areas receiving rainfall over 400cm:
The areas in India that receive rainfall over 400cm are mainly located in the western coast and the northeastern region. These areas experience heavy rainfall due to their proximity to the Arabian Sea and the Bay of Bengal respectively.

1. Western Coast: The western coast of India, also known as the Konkan coast, receives heavy rainfall as it lies in the path of the southwest monsoon winds. The states of Kerala, Karnataka, Goa, and Maharashtra along the coast experience an average annual rainfall of over 400cm. The Western Ghats act as a barrier and force the moist monsoon winds to rise, resulting in significant precipitation.

2. Northeastern Region: The northeastern states of India, including Assam, Meghalaya, Nagaland, Manipur, Mizoram, Tripura, and parts of West Bengal, receive heavy rainfall due to their proximity to the Bay of Bengal and the influence of the northeast monsoon winds. These states are known for their high rainfall, lush green forests, and abundant water resources.

Areas receiving less than 20cm of rainfall:
Certain regions in India receive very low rainfall, less than 20cm annually. These areas are primarily located in the western and northwestern parts of the country, which fall in the rain shadow region of the Western Ghats and the Himalayas.

1. Thar Desert: The Thar Desert in Rajasthan is a prime example of an arid region with scanty rainfall. It falls in the rain shadow of the Aravalli Range and receives less than 20cm of rainfall annually. The lack of vegetation and water scarcity make it a challenging environment for human habitation.

2. Deccan Plateau: The central and southern parts of the Deccan Plateau, including parts of Maharashtra, Karnataka, and Telangana, receive relatively low rainfall. The plateau is surrounded by the Western Ghats and the Eastern Ghats, which block the monsoon winds and result in reduced precipitation.

Direction of the southwest monsoon over India:
The southwest monsoon is the primary rainy season in India, bringing the majority of the country's annual rainfall. It occurs from June to September and moves in a specific direction.

1. The southwest monsoon winds blow from the Arabian Sea towards the Indian subcontinent.
2. These winds are moisture-laden and bring abundant rainfall to various parts of India.
3. The southwest monsoon wind first hits the western coast of India, particularly Kerala, around the end of May or early June.
4. From there, it moves northwards along the western coast, covering states like Karnataka, Goa, and Maharashtra.
5. The monsoon gradually advances towards the northern plains and reaches Delhi by the end of June.
6. It then branches out towards the eastern states such as West Bengal, Bihar, and Jharkhand.
7. The northeast