Bangladesh is one of the most densely populated countries in the world. There are 57 trans‐frontier rivers in the country, the widest being the Brahmaputra River. The river's channels have frequently changed course, but the relationship between such river migrations and human settlement patterns has remained unstudied. In this paper, optically stimulated luminescence and radiocarbon dating techniques were applied to sedimentary and organic materials in the oldest urban center (Wari‐Bateshwar) in Bangladesh. The results showed that the landscape around the urban center was dominated by floodplain and peatland facies between 7.9–7.6 and 4.7–1.6 ka, respectively. Humans occupied this area at ~3.2 ka, and manufactured delicate semi‐precious gemstone beads between ~2.4 and 1.8 ka. The urban center might be the same as an important city of the Gangaridai described in historical records. Due to fluvial migration at ~1.8 ka, the area surrounding the urban center was covered by fluvial sand. Humans might have been forced to abandon the urban center, leading to the bead processing technology in Bangladesh being lost forever.

中文翻译：

---

孟加拉国最古老的市中心经历的变迁与雅鲁藏布江的迁徙有关

孟加拉国是世界上人口最稠密的国家之一。该国有57条跨境河流，其中最宽的是布拉马普特拉河。河流的河道经常改变航向，但是这种河流迁移与人类住区模式之间的关系尚未得到研究。本文将光激发发光和放射性碳测年技术应用于孟加拉国最古老的城市中心（Wari-Bateshwar）的沉积物和有机物。结果表明，城市中心周围的景观分别以7.9–7.6和4.7–1.6 ka之间的洪泛区和泥炭地为主。人类占领了约3.2 ka的区域，并制造了约2.4至1.8 ka的精致的半宝石珠。市中心可能与历史记录中描述的Gangaridai重要城市相同。由于在〜1.8 ka处的河流运移，市中心周围的区域被河流沙覆盖。人们可能被迫放弃了市中心，导致孟加拉国的珠子加工技术永远消失了。