## 3 Results and Discussion  
### Spatial and Temporal Distribution Characteristics of Sites  
This study utilized the kernel density analysis method to investigate the distribution characteristics of archaeological sites from the Paleolithic and Neolithic periods, as well as the Shang to Spring and Autumn periods and the Warring States period in Sichuan Province. The results are presented in Figure 3.  
During the Stone Age, the spatial distribution of sites generally aligned in an EN-WS orientation. The city of Chengdu and its surrounding areas were the most densely distributed regions for site points. This period is represented by sites such as the Baodun Ancient City, Pixian Ancient City, and Chongzhou Zighu Ancient City, which formed the most prominent kernel density hotspots. This indicates that this region was likely a major center of human habitation during the Stone Age. These sites are typical representatives of the Baodun culture (approximately 4800 years ago), the oldest archaeological culture traceable in the Chengdu Plain. Most of these sites were settlements where ancient humans gathered, and they were gradually excavated in the 1990s. Similarly, a significant cluster of sites was observed in the southern part of the Aba Tibetan and Qiang Autonomous Prefecture, suggesting that this area may have been an important location for human activities. In the southern part of the northwestern Sichuan Plateau, counties such as Barkam and Jinchuan in the Aba Tibetan and Qiang Autonomous Prefecture were areas where various ethnic groups settled. Representative sites in this region include the Shenxianbao site and the Shiguangdong site, which are historical and cultural landscapes reflecting the convergence and integration of the Yellow River Basin culture, Yangtze River Basin culture, Central Plains culture, and ethnic cultures. In contrast, other regions, such as eastern, southern, and southwestern Sichuan, had more dispersed sites with lower densities, which could be attributed to the natural environmental conditions or patterns of human activity at the time. During the Shang to Spring and Autumn periods, the distribution of site points became more concentrated. Notable examples include the Sanxingdui site in Guanghan, a core site of the Sanxingdui culture (approximately 4000 years ago), as well as the Jinsha site and Shierqiao site, core sites of the Shierqiao culture (approximately 3200 years ago). These sites formed a distinct cluster around the areas of Chengdu and Mianyang, indicating that this region likely served as a central hub of human activity during the Shang to Spring and Autumn periods. Additionally, Ya'an and Meishan also exhibited a considerable number of site points, and although their density was lower than that of the core areas, they still showed a notable degree of clustering, suggesting a supplementary role in human settlement. In contrast, the eastern and southern parts of the Sichuan Basin, as well as western Sichuan, had fewer site points and did not form clear high-density cores, possibly  
Figure 3: Spatial–temporal distribution characteristics of heritage sites in Sichuan Province: (**a**) Stone Age, (**b**) Shang to Spring and Autumn Period, and (**c**) Warring States Period. due to topographical constraints, indicating that these areas were less significant centers of human activity during this period. During the Warring States period, the distribution of site points displayed a multicenter clustering pattern. A distinct high-density core emerged in the southern part of the Liangshan Yi Autonomous Prefecture, characterized by a dense concentration of site points. This may be attributed to the development of transportation networks, ethnic migration, and intercultural exchanges at the time. Representative sites near Liangshan Prefecture include the Muxigou site and the Wangjiatian site, among others. These sites are closely associated with the Dashi Tomb culture (approximately 3000 years ago) distributed in Liangshan Prefecture.