Settlement adaptation and social evolution under mid-holocene environmental duress in the Yellow River Basin

This study aims to elucidate the adaptation mechanisms of prehistoric settlements in the Yellow River Basin to extreme climate events spanning from the pre-Yangshao period (9.0–7.0 cal. ka BP) to the Bronze Age (4.0–2.0 cal. ka BP). By integrating archaeological site data with ancient environmental records and employing spatial statistical methods such as kernel density estimation and nearest neighbor analysis, this research reconstructs the spatial and temporal evolution of settlement patterns under climate stress. Furthermore, it discusses the relationship between these patterns and natural disasters, uncovering the mechanisms of human-land interaction and the adaptive strategies that shaped regional resilience during periods of environmental stress. The results reveal three key findings. Firstly, the distribution of settlements exhibits significant spatial differentiation; while the middle reaches consistently maintained high density, a secondary core emerged in the upper Hehuang Valley during the Yangshao period. Secondly, settlement patterns demonstrate simultaneous trends of expansion in scale and reduction in number, indicating an increase in social complexity and stratification, which laid the groundwork for early state formation. Thirdly, the selection of settlement sites reflects clear climate adaptation: the average elevation rose by 56.98 m from the Yangshao to Longshan periods, and the proportion of settlements located farther from water sources increased by 12.3 % during the late Longshan period, strongly correlating with flood sediment records. Additionally, erosion and sedimentation in downstream areas provided fertile land, playing a crucial role in sustaining social development. This study illustrates that mid-Holocene climate variability, particularly in the form of intensified flooding and environmental pressures, drove adaptive strategies such as elevation migration and spatial differentiation. These dynamics, coupled with emerging sociopolitical structures, facilitated the rise of early complex societies in the middle and lower Yellow River Basin.