## 3 Results and Discussion
### Spatial and Temporal Distribution Characteristics of Sites
The area near Chengdu still exhibited a significant high-density clustering of sites, indicating that by the Warring States period, the Chengdu region may have developed relatively mature settlements. However, during this time, new types of burial sites emerged, such as earthen pit tombs and boat-coffin tombs. Examples include the Warring States earthen pit tombs in the Shiren Community on the western outskirts of Chengdu and the boat-coffin tombs on Chengdu's Commercial Street. The diversification of archaeological site types provides more comprehensive evidence for the study of Shu culture. Conversely, the eastern and western regions of Sichuan had relatively sparse site distributions without distinct high-density cores, implying that these areas were not primary centers of human activity during this period. This could be due to geographical limitations, such as the unsuitability of high-altitude regions for habitation, as well as constraints on transportation and social development at the time. In kernel density calculations, varying bandwidths significantly influenced the results. Considering the substantial differences in the spatial distribution of archaeological site points across different historical periods in Sichuan Province, distinct bandwidths were employed for each period's kernel density analysis. Specifically, this study selected bandwidths of 80,000 m for the Stone Age, 12,000 m for the Shang to Spring and Autumn periods, and 60,000 m for the Warring States period. These choices were guided by the unique distribution characteristics and density of site points in each era, ensuring that the results accurately reflected both localized clustering features and overall distribution trends. Overall, from the Stone Age to the Warring States period, the spatial distribution of site points in Sichuan Province transitioned from widespread dispersion to relative concentration. The continuous presence of site distributions from the Stone Age through the Shang, Zhou, Spring and Autumn, and Warring States periods indicates that these regions maintained their significance as areas of human activity over an extended period. Notably, the Chengdu Plain consistently served as a core cluster of archaeological sites. Additionally, the emergence of new high-density site areas in southern Sichuan during the Warring States period may be closely linked to factors such as the natural environment, transportation routes, cultural expansion, and economic development. As shown in Figure 4, the spatial distribution of archaeological sites in Sichuan Province from the Stone Age to the Warring States period demonstrated a significant regional evolution trend. During the Stone Age, sites were extensively dispersed throughout the province, with Aba Prefecture (186 sites), Chengdu (78 sites), Liangshan Prefecture (52 sites), and Ganzi Prefecture (31 sites) hosting the highest concentrations. The selection of settlement locations during this period was likely influenced by natural environmental factors, such as water sources, climate, and resource availability. In the Shang to Spring and Autumn periods, the distribution of sites experienced a marked shift, with the Chengdu Plain emerging as a prominent cultural center. The number of sites in Chengdu increased dramatically to 157, while Deyang (39 sites) and Nanchong (34 sites) also became areas with relatively dense site distributions. Conversely, the number of sites in highland regions, like Aba, Ganzi, and Liangshan Prefectures, significantly decreased. This transformation can be attributed to agricultural development, advancements in social organization, and the establishment of centralized governance, leading to a concentration of human activity in the Chengdu Plain. During the Warring States period, the distribution pattern of sites underwent another adjustment. The number of sites in Chengdu sharply declined to 40, while the number of sites in Liangshan Prefecture surged to 136, forming a new high-density archaeological site area.