Bronze Age monumental earthworks of the Friuli Plain (NE Italy): from LiDAR-based morphometric analysis to the reconstruction of settlement patterns and organization

In this study, we use high-resolution data from airborne Light Detection and Ranging (LiDAR) acquisitions to comprehensively analyse late prehistoric earthwork structures in the alluvial plain of Friuli (NE Italy). By comparing LiDAR-derived models with direct topographic surveys of the structures carried out in the past we provide a detailed overview of the main characteristics of the structures. The new documentation, including Digital Terrain Models (DTMs), profiles and 3D models of the preserved structures, refines the topographic information collected by previous scholars and offers new insights into the development of sophisticated building techniques by Bronze Age communities. Additionally, by converting earthwork volumes into energetics and combining workforce investment analysis with other archaeological proxies—particularly site size and distribution—we have supported the analysis of settlement patterns and organization. Assuming 100 hypothetical full-time workers, the construction of burial mounds would have required from 1 week to 2 months; phase 3 monumental embankments at Sedegliano, Savalons, and Galleriano forts would have taken 4–10 months while 2.5–4 years at Udine. The Udine mound would have demanded up to 28 times the labour needed for other forts’ embankments, requiring approximately 11 years to complete and likely necessitating additional workforce from nearby settlements. This approach reveals the emergence of a defined hierarchical settlement system in the Friuli plain during the Recent Bronze Age, with the fort of Udine serving as a top-order settlement within a polity of smaller ones, akin to those recognized in the nearby regions of the Po Plain.