Artificial dwelling mounds in Dutch wetlands: Regional archives of human-landscape interactions (500 BCE – Present)

Human-made earthen mounds are known from wetland environments across the globe. Having served a wide variety of purposes, these archaeological mounds are frequently described as heavily understudied yet fragile archives of past human behaviour and paleoenvironments. Furthermore, they often still fulfil important roles in regional cultural identities and social memory. In this paper we focus on dwelling mounds, which are defined as deliberately raised anthropogenic mounds with a dwelling function, created in anticipation of floods and drainage issues in coastal and fluvial wetland areas. We present the first national-scale study of dwelling mounds in the Netherlands. Our inventory identified almost 9000 dwelling mounds, which was far more than expected. They were erected in a wide variety of wetland settings from the Iron Age (c. 500 BCE) onwards. Main forcing agents of mound construction operated on rapid episodic timescales including (1) coastal flooding and storm surges and (2) fluvial flooding and over gradual, continuous timescales including (3) shoreline shifts (e.g. due to regional sea-level rise or changing palaeogeography) and (4) peat/clay-on-peat subsidence. These forcing agents were active in different combinations and exhibited feedbacks with human landscape engineering. Both individual sites and entire wetland areas could follow highly diverse trajectories. Our results show the great potential of dwelling mounds as knowledge archives on past water adaptation strategies, which may inform future developments, and also urge a reassessment of current heritage management strategies.