Early human settlements and mobility patterns in the Sichuan–Chongqing region from the late Neolithic to the Bronze Age

The Sichuan-Chongqing region is among the key regions hosting human activities in Southwest China. Although archeological excavations in the region have been on the rise, providing insights into the regional cultural sequence, research on the evolution process of sites from a twin-city perspective remains limited. In this study, geographic information system (GIS) analysis was used to examine the spatiotemporal distribution of settlements in the region from the Neolithic to Bronze Age. Correlations between the distribution of archeological sites and environmental factors and the directionality of human mobility were wxplored. The results indicate that settlement distribution is strongly influenced by environmental factors. Ancient societies considered moderate elevation, convenient distance from rivers without flooding risk, and suitable soil for cultivation as the three main factors when selecting settlement sites. Sites respond to environmental change in different periods based on various factors, such as the slope, aspect, distance from the river, and soil type, and are mainly located in areas with slopes <10°, facing south or west, and within a 2 km radius of rivers. As human reliance on water resources increases with improved productivity, limitations imposed by the natural environment decrease. Notably, since the Neolithic period, soil fertility, water, and topography have been key factors affecting the distribution of settlements. Compared with single factors, interactions among the factors exhibit greater explanatory power for the regional spatial distribution characteristics of settlement sites in the Sichuan-Chongqing region. The distribution of sites from the Neolithic Age to the Western Zhou Dynasty show a decrease in migration patterns along rivers in the Eastern Zhou Dynasty in the Chongqing region, while also demonstrating enhanced clustering. In addition, the dual-center trend intensified gradually in the Sichuan–Chongqing region.