When I first became co-director of an archaeological project at Jebel Barkal in northern Sudan in 2018, I was amazed by the site’s pyramids, temples and palaces. It had been an urban center in the ancient empire of Kush, which dominated the Nile Valley off and on for over 2,000 years, from 2000 B.C.E. to 350 C.E.
Panorama of Jebel Barkal with royal pyramids at left.
Gregory Tucker
I was far from alone in admiring the ruins – European and American travelers have visited and archaeologists had documented the site for the past two centuries. More recently, Jebel Barkal was recognized as a UNESCO World Heritage site in 2003.
But researchers still know so little about the ancient city and its residents, particularly compared with other ancient cities of Egypt, Assyria, Greece and Rome. Where did nonroyal people live? What did they eat? We don’t even know how they got their water, since the site is about a mile away from where the Nile flows today. Could there have been a nearby channel of the Nile that has since filled in? What was this landscape like when Jebel Barkal was a major urban center? More broadly, how did changes in climate over the past 4,000 years affect the growth of the city?
Some of these questions can be studied by a field called geomorphology, the study of how the Earth’s surface changes, especially by erosion. To learn more about how the landscape around Jebel Barkal had changed over millennia, I invited two Dutch geomorphologists, Jan Peeters and Tim Winkels, who had previously worked on Nile landscapes in Egypt, to come to Sudan to design a study.
The Nile as a source of life
The Nile runs through Sudan, past the ancient city of Jebel Barkal and then through Egypt before reaching the Mediterranean Sea.
Peeters et al PNAS 2026, CC BY
The Nile floods at the end of every summer, as rains from the Indian Ocean monsoon fall on the highlands of East Africa. The ancient historian Herodotus famously called Egypt “the gift of the Nile” because in Egypt. the rich silt the floods deposited every year made for fertile fields. Egyptians retained the floodwaters in ponds and basins to use later for irrigation.
Upstream in Sudan, however, the underlying geology and geomorphological setting is different. This stretch of the Nile is interrupted by bedrock outcrops that break the flow of the river by what are called cataracts: islands, rapids and even small waterfalls.
The Nile also cuts more deeply into the bedrock and is more confined to the riverbed in Sudan than in Egypt. The floodplains here are generally more limited. As a result, it’s harder to hold onto water to use for irrigation after the annual flood has passed.
Our team wanted to understand how the ancient city interacted with the Nile and how that relationship developed through time as climate and the local environment shifted. Our recent study, published in the Proceedings of…
