Terai

The Terai is a lowland region in southern Nepal and northern India that runs along the southern edge of the Himalayas. The term Terai designates a belt of flat, fertile alluvial plains and wetlands between the Himalayan foothills to the north and the northern edge of the Indo-Gangetic Plain to the south. In Nepal, the Terai spans the country’s southern border from the Mechi River in the east to the Mahakali in the west; in India, it covers parts of several states along the northern frontier with Nepal and is often treated as a broad ecological zone rather than a fixed political region.

Geography and climate

The Terai lies at elevations generally around 60 to 100 meters above sea level, with some areas slightly higher. The climate is typically subtropical to tropical, with a pronounced monsoon season, high humidity, and a long growing season. Soils are predominantly alluvial and highly fertile, shaped by the region’s rivers and seasonal floods. River systems such as the Koshi, Gandak, Ghaghara, and Rapti influence drainage, agriculture, and flood dynamics.

Ecology and protected areas

Historically, the Terai supported extensive wetlands, grasslands, and riverine forests. It remains a biodiversity hotspot, home to large mammals and numerous bird species. Notable protected areas include Chitwan National Park and Bardiya National Park in Nepal, and the Dudhwa Tiger Reserve in India. Transboundary conservation initiatives, such as the Terai Arc Landscape, aim to maintain habitat connectivity across national borders.

Economy and society

The Terai is the most densely populated and agriculturally productive zone in both Nepal and India. Principal crops include rice, wheat, maize, sugarcane, and oilseeds. The region hosts major towns, trade corridors, and cross-border commerce, alongside ongoing development and land-use changes. Challenges include floods, earthquakes, land-use pressures, and human-wildlife conflict in areas near protected habitats.