The Sistan Basin is a closed endorheic depression shared between southeastern Iran and southwestern Afghanistan. It is one of the most wind-exposed and water-stressed regions in the world, with the Hamun lakes at its centre and the 120-day wind a defining ecological force.

The Sistan Basin in southeastern Iran and southwestern Afghanistan was one of the cradles of Bronze Age civilisation. Shahr-e Sukhteh, a city of up to 25,000 people active from 3200 to 1800 BC on the western shore of the Hamun lakes, was a centre of craft production, long-distance trade, and artistic innovation. The basin’s productivity depended entirely on the Helmand River’s annual floods and the storage capacity of the shallow Hamun lakes. Medieval Arab geographers described Sistan as a prosperous and densely settled region. Repeated invasions, including the devastating Mongol campaigns of the 13th century, disrupted its agricultural systems and reduced its population.

The Sistan Basin is one of Iran’s most economically marginalised and environmentally stressed regions. The drying of the Hamun lakes has destroyed the fishing and pastoral economy that sustained rural communities for millennia. Seasonal dust storms driven by the Wind of 120 Days have made agriculture nearly impossible in the immediate basin. The city of Zabol is frequently cited as one of the most polluted cities in Iran by particulate matter. The combination of environmental collapse, ethnic marginalisation of the Baluch population, and proximity to Afghanistan’s instability makes the basin a persistent security and humanitarian concern.