In the south-eastern margins of the Zimbabwe plateau sit the ruins of southern Africa’s first major city, Great Zimbabwe. The city was established as the capital of the Karanga kingdom in the 11th century AD, and remained occupied until the 17th century. How Great Zimbabwe successfully kept its residents and surrounding farmland supplied with water, in an area frequently plagued by drought, has puzzled researchers for many years. Now a recent study has taken a multidisciplinary approach to this mystery, using a combination of remote sensing, excavation, and geoarchaeological surveys, as well as ethnographic study of modern groups in the area.
The researchers identified a system of large, circular depressions (c.40m × 10m) in the landscape surrounding Great Zimbabwe, locally referred to as dhaka pits. These depressions had previously been recognised as human-made, but have never been investigated before, and it was thought that they were simply places where clay used in the city’s construction was gathered. However, it appears that this is not the whole story. It seems that the dhaka pits were in fact deliberately placed in locations where they would collect surface water and store ground water for use in dry periods of the year. These reservoirs were part of a wider-scale water management and supply system, that were complemented by springs and wells, some of which are still in use by modern communities in the area today.
While some of the dhaka pits have been dated to between the 16th and the 18th centuries – a period associated elsewhere with the Little Ice Age – precise dating and further study of the pits is needed, but the research shows that Great Zimbabwe had an advanced hydrological system much earlier than previously thought. The study also demonstrates the value of an ongoing dialogue between different disciplines and local knowledge systems, which could inform modern approaches to climate management in the area as well.
The paper has been published in Anthropocene (https://doi.org/10.1016/j.ancene.2022.100357).
Text: Amy Brunskill / Image: Innocent Pikirayi Please send your images to email@example.com. They must be high resolution (300 dpi) and in landscape format, ideally 20cm high by 30cm wide.