The persistence of ancient settlements and urban sustainability

Abstract

We propose a dedicated research effort on the determinants of settlement persistence in the ancient world, with the potential to significantly advance the scientific understanding of urban sustainability today. Settlements (cities, towns, villages) are locations with two key attributes: They frame human interactions and activities in space, and they are where people dwell or live. Sustainability, in this case, focuses on the capacity of structures and functions of a settlement system (geography, demography, institutions) to provide for continuity of safe habitation. The 7,000-y-old experience of urbanism, as revealed by archaeology and history, includes many instances of settlements and settlement systems enduring, adapting to, or generating environmental, institutional, and technological changes. The field of urban sustainability lacks a firm scientific foundation for understanding the long durée, relying instead on narratives of collapse informed by limited case studies. We argue for the development of a new interdisciplinary research effort to establish scientific understanding of settlement and settlement system persistence. Such an effort would build upon the many fields that study human settlements to develop new theories and databases from the extensive documentation of ancient and premodern urban systems. A scientific foundation will generate novel insights to advance the field of urban sustainability.

Keywords: archaeology; cities; persistence; sustainability; urbanism.

Fig. 1.

Persistence (length of occupation) of a sample of premodern settlements. The figure shows the total length of continuous settlement. This is an illustrative sample; it is not random or systematic. See SI Appendix, Fig. 1, for sources of these data and discussion.

Fig. 2.

Histograms showing the distribution of settlement occupation spans for large samples of settlements in the Basin of Mexico (Left) and central Italy (Right). For each histogram, the median value is shown in blue and the mean and 1 and 2 SDs above the mean are shown in red. See SI Appendix, Fig. 2, for sources of these data and discussion.

Fig. 3.

Size trajectories of five long-lasting cities. See SI Appendix, Fig. 3, for sources of these data and discussion.

Fig. 4.

Three hypothesized major causes or determinants of settlement persistence: settlement size (demography), institutions, and geography. These play out at different spatial and social scales, from households to networks to landscapes.