## 3 Results  
### Spatial Patterns of Interprovincial Rural Migration  
According to population census data, the scale of interprovincial migration of China's rural population in 2020 increased from 25.80 million in 2000 to 94.71 million, with an average annual growth rate of 6.70%. Over a 10-year period, the average annual growth rate of the scale of interprovincial migration of the rural population reached 9.59% in 2000-2010, while it was only 3.88% in 2010-2020. This implies that the interprovincial migration of China's rural population continued to grow from 2000 to 2020 but showed a slowing trend. Spatially, the scale of rural emigration in each province from 2000 to 2020 is characterized by differentiation along the Heihe-Tengchong Line, with a clear \"center-periphery\" \begin{table}
\begin{tabular}{l l l l} \hline \hline
**Dimension** & **Variable** & **Definition** & **Abbreviation** \\ \hline Regional environment & Per capita GDP & GDP divided by mid-year population (CNY) & _S\_pgdp/D\_pgdp_ \\ \hline Regional environment & Number of beds in health facilities per 1000 people & Number of beds of health care institutions at year-end/population at year-end \(\times\) 1000 (beds) & _S\_health/D\_health_ \\ \hline Regional environment & Internet penetration rate & Number of internet users as a percentage of total resident population (\%) & _S\_internet/D\_internet_ \\ \hline Regional environment & Natural disasters & Total population affected by natural disasters (10,000 person-times) & _S\_disaster/D\_disaster_ \\ \hline Spatial barriers & Topographic relief & Standard deviation of regional DEM rasters (-) & _S\_topo/D\_topo_ \\ \hline Spatial barriers & Spatial distance & Distance between centers of gravity based on administrative maps (km) & _distance_ \\ \hline \hline \end{tabular}
\end{table} 
Table 2: _Cont._pattern, i.e., the central provinces were the high-value area, while the border and eastern coastal provinces were mostly the low-value area (Figure 2). Specifically, the scale of provincial rural emigration in 2000 was generally small, with 17 provinces below 0.50 million, and even 8 provinces less than 0.10 million, including Tibet (8.75 thousand), Beijing (23.70 thousand), Tianjin (28.23 thousand), Shanghai (30.64 thousand), Qinghai (46.03 thousand), Ningxia (48.78 thousand), Xinjiang (54.58 thousand), and Hainan (56.25 thousand). There are 9 provinces exceeding 1 million, of which the largest is Sichuan (3.65 million), followed by Hunan (2.79 million) and Anhui (2.71 million). In 2010, the number of provinces in which rural emigration was greater than 1 million increased to 18, with Anhui, Sichuan, Henan, and Hunan exceeding 5 million, reaching 8.30 million, 7.23 million, 6.98 million, and 5.96 million, respectively; the only provinces with fewer than 0.10 million were Tibet (20.30 thousand), Shanghai (26.37 thousand), Beijing (43.84 thousand), and Tianjin (63.90 thousand). In 2020, the number of provinces with rural emigration greater than 1 million increased to 20, with Henan and Anhui even exceeding 10 million, reaching 11.07 million and 10.82 million, respectively; the provinces lower than 0.10 million were Tibet (55.83 thousand), Shanghai (66.28 thousand), and Beijing (80.97 thousand). This highlights the continued concentration of emigration from central provinces. While rural emigration exhibited a clear spatial pattern, the destinations of these migrants also revealed distinct regional preferences. In terms of destination, the most popular provinces for rural immigration during the research period were primarily the eastern coastal provinces of Beijing, Shanghai, Zhejiang, Jiangsu, Fujian, and Guangdong, and the ratio of interprovincial rural immigration in these six provinces accounted for 70.31%, 77.03%, and 72.59% of the national total in 2000, 2010, and 2020, respectively.