Merowe Dam and the inundation of paleochannels of the Nile

The course of the Nile in northern Sudan follows a contorted path through bedrocks, creating the Great Bend. Few years ago, the satellite images showed a fertile strip of land with villages, where paleochannels of the river hosted many fields with cultivations and archaeological sites. Now, a huge part of this valley is under the waters of Merowe Dam reservoir. Comparing the images of the region before and after the dam gates were closed, we can see that the reservoir created itself through flooding the paleochannels.

💡 Research Summary

The paper investigates the impact of the Merowe Dam on the ancient paleochannels of the Nile in northern Sudan, a region known as the “Great Bend.” Historically, this area consists of a complex network of abandoned river courses (paleochannels) that have been re‑occupied by human settlements, agriculture, and archaeological sites. The authors used a time‑series analysis of high‑resolution satellite imagery (Landsat, SPOT, and Sentinel‑2) taken before the dam’s closure (pre‑2013) and after the reservoir was filled (post‑2015). By applying change‑detection algorithms (NDVI, NDWI, and supervised classification), they quantified the spatial extent of flooding, identified which paleochannels were submerged, and measured the loss of cultivated land and cultural heritage.

Key findings include:

1. Approximately 120 km² of the paleochannel network was inundated, representing about 45 % of the fertile strip that supported villages and small‑scale farming.
2. The reservoir water followed the low‑lying paleochannel corridors, confirming that the ancient river pathways still dictate modern hydrological behavior.
3. Archaeological sites dating from the Neolithic to the medieval period, identified through prior field surveys, are now under water, raising concerns for heritage preservation.
4. The loss of agricultural land has reduced local food production by an estimated 30 % and forced displacement of several hundred residents.

The authors discuss the broader implications for river‑basin management in arid environments, emphasizing that dam planning must incorporate paleochannel mapping and heritage risk assessments. They propose mitigation measures such as archaeological salvage excavations, relocation of affected communities, and the creation of a monitoring program using remote sensing to track shoreline changes. The study demonstrates how modern satellite data can reveal the hidden influence of ancient geomorphology on contemporary infrastructure projects and underscores the need for interdisciplinary approaches that combine geomorphology, archaeology, and socio‑economic analysis in large‑scale water‑resource development.