Integrating spatial and legacy data to understand archaeological sites in their landscape. A case study from Unguja Ukuu, Zanzibar

Abstract

Spatial analysis is paramount for understanding, monitoring, and conserving ancient settlements and cultural landscapes. Advancing remote sensing and prospection techniques are expanding the methodological frame of archaeological settlement analysis by enabling remote, landscape-scale approaches to mapping and investigation. Whilst particularly effective in arid lands and areas with sparse or open ground cover, such as vegetation and buildings, these approaches remain peripheral in tropical environments because of technical and contextual challenges. In tropical Eastern Africa, for example, scales, resolution and visibility are often compromised by thick vegetation cover, inadequate access to, if not lack of, imagery resources and technologies, and the availability of comparative archaeological data for interpretation. This

Open-Access Archaeological Predictive Modeling Using Zonal Statistics: A Case Study from Zanzibar, Tanzania

“…Research on the Swahili Coast has definitively revealed the scale, complexity, and interconnectedness of non-elite, rural settlement (Kusimba et al 2013;LaViolette and Fleisher 2018). Increasingly, archaeologists have sought to investigate the environmental dynamics of Swahili settlement landscapes (Faulkner et al 2022;Fitton et al 2023;Kotarba-Morley et al 2022;Pawlowicz et al 2014;Prendergast et al 2017;Quintana Morales et al 2022;Walshaw and Stoetzel 2018). This paper contributes to this growing body of research by modeling and testing the environmental affordances that influenced regional settlement trends.…”

“…In African archaeology, recent studies have used a combination of remote sensing and spatial analysis for site detection, predictive modeling, and for understanding archaeological landscapes (Biagetti 2017;Davis and Douglass 2021;Fitton et al 2023Harrower et al 2020Klehm et al 2019;Ochungo et al 2022;Pawlowicz et al 2020;Reid 2016Reid , 2020Thabeng et al 2020). Creating models for site detection with multispectral imagery is increasingly accessible, with resources like Landsat, Planet, and Sentinel 2 imagery becoming available at increasingly high spatial, spectral, and temporal resolutions.…”

“…To work around this problem, this paper presents a case study for an alternative method: predictive modeling through zonal statistical analyses of environmental raster images in comparison to training data, which are used to the weight a final summative model (see Fitton et al 2023 for another regional study integrating multiple geospatial and legacy datasets on Zanzibar). This method is based around quantifying the most suitable spatial zones for the occurrence of specific phenomena by summing weighted raster datasets using raster calculations (e.g., Behr et al 2017;Kuria et al 2011).…”

“…The island of Zanzibar is environmentally diverse, with two major ecological zones: an agriculturally fertile northwestern region with deep soils and above-ground streams, and a rocky, agriculturally marginal karstic limestone landscape in the south and east, where water does not persist above ground (Alders 2023). Archaeologists have increasingly investigated ecological relationships between Swahili people and their landscapes on Zanzibar Fitton et al 2023;Kotarba-Morley et al 2022;Prendergast et al 2017;Quintana Morales et al 2022). This study builds on this recent research, contributing to an understanding of the environmental affordances that structured long-term settlement and social change.…”