Settlement Adaptation to a Changing Coastline: Archaeological Evidence from Tanzania, during the First and Second Millennia AD

Abstract

ABSTRACT Any coastline subject to progradation or regression provides scope for archaeological study of maritime settlement changes through time. The Tanzanian Coast is the focus of this study of Swahili adaptations to geomorphological change in a dynamic marine environment. Archaeological survey around Kilwa Kisiwani and Kaole has yielded extensive evidence of coastal change affecting settlement over the last two millennia. Falling relative sea level in the first and early second millennia AD led to the development of sand terraces and spits upon which settlement developed at both locations. From the late fourteenth century, increased erosion associated with sea level rise or human activity prompted protective measures at Kilwa. In contrast, there is no evidence of erosion at Kaole, where accretion in a deltaic environment extended settlement opportunities seaward and silted former landing places. The constant adaptation of settlement to this changing coastline emphasizes the continuity of concerns with sea level change, erosion and sedimentation through to a modern world focussed upon possible impacts of global warming.