TITLE:
Soil Erosion and Deposition in Engaruka Archaeological Farmland, Northern Tanzania
AUTHORS:
George Watene, Felix Mutua, Yueping Nie, Lijun Yu, Thomas Ngigi, Xianhu Wei, Thomas Biginagwa, Christognas Ngivingivi, Leka Tingitana, Yves Hategekimana
KEYWORDS:
Soil Erosion, USPED, UAV, ALOS-PALSAR-2, Engaruka, Archaeological Terraces
JOURNAL NAME:
Journal of Geoscience and Environment Protection,
Vol.14 No.8,
August
31,
2026
ABSTRACT: Soil erosion is a major hydrogeological hazard in archaeological sites within the East Africa Rift System (EARS). Dating back to the 15th century CE, and with its distinct stone-lined irrigation fields, Engaruka is one of the impressive abandoned Archaeological Islands of Intensive Agriculture in East Africa (AIIAEA). Aggressive arid climate coupled with socioeconomic factors e.g. overgrazing and farmland encroachments has resulted to extensive gullying that threatens to degrade the northern half of the site. In this study, we use the Unit Stream Power-based Erosion Deposition (USPED) model and UAV-derived (Digital Elevation Model) DEM to estimate the soil erosion-deposition spatial patterns in Engaruka North Terraced Area, ENTA. We then estimated the volume of sediment removed by erosion on an active section of Intermediate North Gorge (Gully Site), ENTA based on 2023 UAV data. We found the mean soil erosion-deposition rates (Mg∙ha−1∙yr−1) to be 33.9 and 31.1 respectively. Intensive erosion processes are dominant along the EARS foot slope while gullying is concentrated in the low-sloping alluvial areas. The eroded volume was measured to be 5936.4 m3 with a total length of 145.7 m of ancient terracing material eroded away on the surveyed gorge. These findings can be useful in planning for effective soil conservation measures within the site as well as future erosion pin measurement methods. This study emphasizes the influence of landscape changes on soil erosion in East Africa’s archaeological areas towards attaining Sustainable Development Goal (SDG) 11.4.1.