How the end of malaria remade the Tarai

Nepali has a word for it: aul. The aul was the hot, forested lowland where fever struck anyone who stayed through the monsoon. Hill people travelling to India crossed it quickly in winter; armies feared it. For the rulers in Kathmandu, the malarial forest was a natural wall against invasion from the south.

Life before

Only a few peoples lived permanently in the deep forest belts — above all the Tharu, along with Bote, Majhi, Darai, Kumal and others. In the open plains closer to India, Maithil, Bhojpuri and Awadhi farming communities had long been settled, and the Rana government encouraged forest clearing for timber exports and revenue. But large parts of the inner Tarai, like Chitwan and Dang, remained thinly populated.

The campaign

In the 1950s, with support from the United States and international agencies, Nepal began spraying DDT against the mosquitoes that carried malaria. Within a decade cases had fallen dramatically. At the same time, the government opened the Rapti valley in Chitwan to planned resettlement for hill families, especially those hit by floods and landslides.

A new Tarai

What followed was one of the biggest migrations in Nepal's history. Forests were cleared for farms, highways such as the East–West Highway were built, and towns like Bharatpur, Butwal, Itahari and Dhangadhi grew rapidly. Today about half of Nepal's population lives in the Tarai.

The cost

The change brought prosperity to many, but also loss. Tharu and other indigenous communities saw their land pass to newcomers, the forests shrank, and wildlife such as the rhino nearly disappeared — leading to the creation of Chitwan National Park in 1973. The relationship between hill migrants, Madhesi communities and indigenous peoples remains a central theme of Tarai politics.

Malaria today

Malaria has not vanished entirely, but it is now rare and Nepal aims for elimination. Dengue, spread by a different mosquito, has become the bigger worry in recent years — so repellent is still worth packing.