The Terai (Hindi: तराई Nepali: तराइ) is a lowland region in southern Nepal and northern India that lies south of the outer foothills of the Himalayas, the Siwalik Hills, and north of the Indo-Gangetic Plain. This lowland belt is characterised by tall grasslands, scrub savannah, sal forests and clay rich swamps. In northern India, the Terai spreads from the Yamuna River eastward across Himachal Pradesh, Haryana, Uttarakhand, Uttar Pradesh and Bihar. The Terai is part the Terai-Duar savanna and grasslands ecoregion. The corresponding lowland region in West Bengal, Bangladesh, Bhutan and Assam in the Brahmaputra River basin is called 'Dooars'. In Nepal, the Terai stretches over 33,998.8 km2 (13,127.0 sq mi), about 23.1% of Nepal's land area, and lies at an altitude of between 67 and 300 m (220 and 984 ft). The region comprises more than 50 wetlands. North of the Terai rises the Bhabhar, a narrow but continuous belt of forest about 8–12 km (5.0–7.5 mi) wide.
In Hindi the region is called तराई, 'tarāī' meaning "foot-hill". In Nepali, the region is called तराइ 'tarāi' meaning "the low-lying land, plain" and especially "the low-lying land at the foot of the Himālayas". The region's name in Urdu is ترائي 'tarāʼī' meaning "lands lying at the foot of a watershed" or "on the banks of a river; low ground flooded with water, valley, basin, marshy ground, marsh, swamp; meadow".
The Terai is crossed by the large perennial Himalayan rivers Yamuna, Ganges, Sarda, Karnali, Narayani and Kosi that have each built alluvial fans covering thousands of square kilometres below their exits from the hills. Medium rivers such as the Rapti rise in the Mahabharat Range. The geological structure of the region consists of old and new alluvium, both of which constitute alluvial deposits of mainly sand, clay, silt, gravels and coarse fragments. The new alluvium is renewed every year by fresh deposits brought down by active streams, which engage themselves in fluvial action. Old alluvium is found rather away from river courses, especially on uplands of the plain where silting is a rare phenomenon.
A large number of small and usually seasonal rivers flow through the Terai, most of which originate in the Siwalik Hills. The soil in the Terai is alluvial and fine to medium textured. Forest cover in the Terai and hill areas has decreased at an annual rate of 1.3% between 1978 and 1979, and 2.3% between 1990 and 1991. With deforestation and cultivation increasing, a permeable mixture of gravel, boulders and sand evolves, which leads to a sinking water table. But where layers consist of clay and fine sediments, the groundwater rises to the surface and heavy sediment is washed out, thus enabling frequent and massive floods during monsoon, such as the 2008 Bihar flood.
The reduction in slope as rivers exit the hills and then transition from the sloping Bhabhar to the nearly level Terai causes current to slow and the heavy sediment load to fall out of suspension. This deposition process creates multiple channels with shallow beds, enabling massive floods as monsoon-swollen rivers overflow their low banks and shift channels. Many areas show erosion such as gullies.
|Biratnagar, 26°N, 87°E|
|Climate chart (explanation)|
|Chandigarh, 30°N, 77°E|
|Climate chart (explanation)|
In India, the Terai extends over the states of Himachal Pradesh, Haryana, Uttarakhand, Uttar Pradesh, Bihar and West Bengal. These are mostly the districts of these states that are on the Indo-Nepal border:
The Terai in Nepal is differentiated into "Inner" and "Outer" Terai and includes 20 districts.
Most of these valleys are 5–10 km (3.1–6.2 mi) wide (north-south) and up to 100 km (62 mi) long (east-west).
The Outer Terai begins south of the Siwalik Hills and extends to the Indo-Gangetic plain. In the Far-Western Region, Nepal it comprises the Kanchanpur and Kailali districts, and in the Mid-Western Region, Nepal Bardiya and Banke districts. Farther east, the Outer Terai comprises the Kapilvastu, Rupandehi, Nawalparasi, Parsa, Bara, Rautahat, Sarlahi, Mahottari, Dhanusa, Siraha, Saptari, Sunsari, Morang and Jhapa districts.
East of Banke the Nepalese Outer Terai is interrupted where the international border swings north and follows the edge of the Siwaliks adjacent to Deukhuri Valley. Here the Outer Terai is entirely in Uttar Pradesh's Shravasti and Balrampur districts. East of Deukhuri the international border extends south again and Nepal has three more Outer Terai districts.
Several protected areas were established in the Terai since the late 1950s:
Tharu and Dhimal people are the indigenous inhabitants of the Terai forests. Several Tharu subgroups are scattered over most of the Nepal and Indian Terai. They used to be semi-nomadic, practised shifting cultivation and collected wild fruits, vegetables and medicinal herbs. They have been living in the Terai for many centuries and reputedly had an innate resistance to malaria. Dhimal reside in the eastern Nepal Terai, viz Sunsari, Morang and Jhapa districts. In the past, they lived in the fringes of the forest and conducted a semi-nomadic life to evade outbreaks of diseases. Today, they are subsistence farmers.
Maithils inhabit the Indian Terai in Bihar and the eastern Terai in Nepal. Bhojpuris reside in the central and eastern Terai, and Awadhis live in the central and western Terai. Bantawa people reside foremost in two districts of the eastern Terai in Nepal.
Following the malaria eradication program using DDT in the 1960s, a large and heterogeneous non-Tharu population settled in the Nepal Terai. Pahari people from the mid-hills including Bahun, Chhetri and Newar moved to the plains in search of arable land. In the rural parts of the Nepal Terai, distribution and value of land determine economic hierarchy to a large extent. High caste migrants from the hills and traditional Tharu landlords who own agriculturally productive land constitute the upper level of the economic hierarchy. The poor are the landless or near landless Terai Dalits, including the Musahar, Chamar and Mallah. Several Chepang people also live in Nepal's central and eastern Terai districts.
As of June 2011, the human population in the Nepal Terai totalled 13,318,705 people in 2,527,558 households comprising more than 120 different ethnic groups and castes such as Badi, Chamling, Ghale, Kumal, Limbu, Magar, Muslim, Rajbanshi, Teli, Thakuri, Yadav and Majhi speaking people.
The Muslim invasion of northern India during the 14th century caused Hindu and Buddhist people to seek refuge from religious persecution. Rajput nobles and their entourage migrated to the Himalayan foothills and gained control over the region from Kashmir to the eastern Terai during the next three centuries.
Until the mid 18th century, the Nepal Terai was divided into several smaller kingdoms, and the forests were little disturbed. The Kingdom of Chaudandi ruled by scion of Palpa Kingdom controlled the Terai districts of Saptari, Siraha, Dhanusa, Mahottari and Sarlahi. The Makwanpur Kingdom controlled the central Terai region of present-day Nepal. The Bijayapur Kingdom ruled Sunsari, Morang and Jhapa districts. The Tulsipur State in the Dang Valley of Nepal's western Terai was also an independent kingdom, until it was conquered in 1785 by Bahadur Shah of Nepal during the unification of Nepal. The Shah rulers also conquered land in the eastern Terai that belonged to the Kingdom of Sikkim. Since the late 18th century, they encouraged Indian people to settle in the Terai and supported famine-stricken Bihari farmers to convert and cultivate land in the eastern Nepal Terai. From at least 1786 onwards, the Shah rulers appointed government officers in the eastern Terai districts of Parsa, Bara, Rautahat, Mahottari, Saptari and Morang to levy taxes, collect revenues, and capture elephants and rhinos.
The far-western and mid-western regions of the Nepal Terai called 'Naya Muluk' (new country) lay on the northern periphery of the Awadh dynasty. After Nepal lost the Anglo–Nepalese War in 1816, the British annexed these regions in the Terai when the Sugauli Treaty was ratified. But as reward for Nepal's military aid in the Indian Rebellion of 1857, they returned some of this region in 1860, namely today's districts Kanchanpur, Kailali, Banke and Bardiya.
Indian immigration increased between 1846 and 1950. Immigrants settled in the eastern Nepal Terai together with native Terai peoples. The Indian Terai remained largely uninhabited until the end of the 19th century, as it was arduous and dangerous to penetrate the dense and marshy malarial jungle. The region was densely forested with stands of foremost Sal.
Heavy logging began in the 1920s. Extracted timber was exported to India to collect revenues. Cleared areas were subsequently used for agriculture. But still, the Terai jungles were teaming with wildlife.
Inner Terai valleys historically were agriculturally productive but extremely malarial. Some parts were left forested by official decree during the Rana dynasty as a defensive perimeter called Char Kose Jhadi, meaning 'four kos forest'; one kos equals about 3 km (1.9 mi). A British observer noted, "Plainsmen and paharis generally die if they sleep in the Terai before November 1 or after June 1." British travelers to Kathmandu went as fast as possible from the border at Raxaul to reach the hills before nightfall.
Malaria was eradicated using DDT in the mid-1950s. Subsequently, people from the hills migrated to the Terai. About 16,000 Tibetan refugees settled in the Nepal Terai in 1959–1960, followed by refugees of Nepali origin from Burma in 1964, from Nagaland and Mizoram in the late 1960s, and about 10,000 Bihari Muslims from Bangladesh in the 1970s. Timber export continued until 1969. In 1970, the king granted land to loyal ex-army personnel in the districts of Jhapa, Sunsari, Rupandehi and Banke, where seven colonies were developed for resettling about 7,000 people. They acquired property rights over uncultivated forest and 'waste' land, thus accelerating the deforestation process in the Terai. Between 1961 and 1991, the annual population growth in the Terai was higher than the national average, which indicates that migration from abroad occurred at a large scale. Deforestation continued, and forest products from state-owned forest were partly smuggled to India. Community forestry was introduced in 1995. Since the 1990s, migration from the Terai to urban centres is increasing and causing sociocultural changes in the region.
The Janatantrik Terai Mukti Morcha is a separatist organisation founded in 2004 by Jay Krishna Goit with the aim of gaining independence for the Terai (Madhesh) region from Nepal. Organisation members have been responsible for various acts of terrorism including bombings and murders. Other armed outfits have appeared that also demand secession through violent means including the "Terai Army", "Madhesh Mukti Tigers" and the "Tharuwan National Liberation Front". There is also movement that is demanding the secession of the region from Republic of Nepal led by CK Raut called the Alliance for Independent Madhesh, a group of activists, parties and organisations.
The most significant border dispute of the Indo-Nepal boundary in the Terai region is the Susta area. In the Susta region, 14,500 hectares of land is generally dominated by Indian side with support of Seema Shashatra Bal (SSB) forces.
After the Nepalese Constituent Assembly election, 2008, Indian politicians kept on trying to secure strategic interests in the Nepal Terai, such as over hydropower energy, development projects, business and trade. The government of Nepal has accused India of imposing an undeclared blockade in 2015. India has denied the allegations, stating the supply shortages have been imposed by Madheshi protesters within Nepal, and that India has no role in it.
The Terai is the most productive region in Nepal with the majority of the country's industries. Agriculture is the basis of the economy. Major crops include rice, wheat, pulses, sugarcane, jute, tobacco, and maize. In the eastern districts from Parsa to Jhapa agro-based industries are supported including: jute factories, sugar mills, rice mills and tobacco factories. The Terai is also known for beekeeping and honey production, with about 120,000 colonies of Apis cerana.
Cities with more than 50,000 inhabitants in Nepal's Terai include:
|Biratnagar||Morang||166,674||agro-industry, education, trade and transport hub|
|Birganj||Parsa||112,484||trade and transport hub, agro- and other industries|
|Dharan||Sunsari||95,332||tourism hub and destination, education, financial services|
|Bharatpur||Chitwan||89,323||agro-industry and food processing, tourism, health care, education|
|Bhim Dutta||Kanchanpur||80,839||transport hub, education, health services|
|Butwal||Rupandehi||75,384||transport hub, retailing, agro-industry, health care, education|
|Hetauda||Makwanpur||68,482||transport hub, cement factory, large and small-scale industries|
|Janakpur||Dhanusa||67,192||transport hub, agro-industry, education, health care, pilgrimage site|
|Nepalganj||Banke||57,535||transport hub, retailing, financial services, health services|
|Siddharthanagar||Rupandehi||52,569||trade and transport hub, retailing, tourist and pilgrim services|
The Mahendra Highway crosses the Nepal Terai from Kankarbhitta on the eastern border in Jhapa District, Mechi Zone to Mahendranagar near the western border in Kanchanpur District, Mahakali Zone. It is the only motor road spanning the country from east to west.
Tourist attractions in the Terai include: