The Chronology of Helmand Changes in Seistan

The Helmand River has three distinct beds in Seistan: the North Channel, the Trākun River, and the Sanā Rūd. Over the ages, the Helmand has undergone repeated changes and shifted from one bed to the other. This article reconstructs the Helmand channel alterations based on fieldwork observations, existing archeological investigation reports, and the writings of ancient geographers. It seeks to identify ancient cities, locate ancient weirs and main canals, and establish the chronology of changes of the river channel. It shows that the river flowed in the channel of the Sanā Rūd during the period c.3200-c.1800 BC, in the channel of the Trākun River during the periods c.1800-c.1300 BC, c.200 BC-AD c.400, AD c.1100-c.1700 and finally in the North Channel during c.1300-c.200 BC, AD c.400-c.1100, AD c.1700-present.