Encyclopædia Britannica, Inc.
Andrzej Wrotek (CC-BY-2.0)

The Indo-Gangetic Plain is a large, flat region in South Asia. It extends more than 1,500 miles (2,400 kilometers) from the Arabian Sea in the west to the Bay of Bengal in the east. The plain covers parts of eastern Pakistan, northern India, and Bangladesh. The Himalayas lie to the north, and the Deccan, a broad plateau in India, is to the south. The Indo-Gangetic Plain has an area of about 270,000 square miles (700,000 square kilometers).

The Indo-Gangetic Plain is named for the two main river systems, the Indus and Ganges, that flow through the area. These rivers and many smaller ones provide plenty of water and help create rich, fertile soil for farming. Because of the good soil, warm weather, and flat land, many people live and farm there.

The Ganges River and its tributaries (branches) flow through the middle and eastern parts of the Indo-Gangetic Plain. The Brahmaputra River passes through northeastern India before joining the Ganges in Bangladesh. The Indus and its tributaries flow through the western part of the plain into the historical Punjab region in the north. Punjab means land of the five rivers. It refers to the five rivers—the Jhelum, Chenab, Ravi, Beas, and Sutlej—that flow through the historical region and join the Indus River. In the far west is the dry Thar, or Great Indian, Desert, which features low hills and shifting sand dunes.

The many rivers on the Indo-Gangetic Plain create alluvial soil. It’s formed when the flowing waters deposit materials such as silt, sand, clay, gravel, and organic matter (broken-down matter from dead plants and animals). The soil is good for growing important crops such as wheat and rice. Irrigation systems capture and distribute both river water and the large reserves of groundwater underneath the region.

Hundreds of millions of people live on the Indo-Gangetic Plain. Some of South Asia’s biggest cities are there, including Delhi and Kolkata (formerly Calcutta) in India, Dhaka in Bangladesh, and Lahore in Pakistan. The region is important for farming, trade, and industry. It also has a rich history. Thousands of years ago, one of the world’s first civilizations—the Indus valley civilization—thrived there. Later, many important religions, including Hinduism, Buddhism, and Sikhism, started or spread in this area.

Even though the Indo-Gangetic Plain is rich in resources, it also faces big challenges. When the monsoon winds arrive in summer, heavy rains often cause floods, especially in eastern India and Bangladesh. Because so many people live in the region, problems such as water pollution and air pollution have increased. In addition, disagreements over sharing river water have arisen between India and Pakistan.