基于地理学综合视角的胡焕庸线IPCC复合情景（SSPs-RCPs）模拟和预测

胡焕庸线（简称胡线）是重要的人口分界线,更是一条展现中国自然与人文地理综合视角下的国情分界线。通过构建环境因素影响下的人口潜力模型,结合四组气候系统模式驱动下的作物模型和水文模型,模拟共享社会经济路径（SSPs）和代表性浓度路径（RCPs）复合情景下中国未来近期（2030年）和中期（2050年）人口时空变化趋势。发现：① SSPs情景下中国未来胡焕庸线东西两侧人口比重差距将进一步拉大,而在考虑SSPs-RCPs的复合情景下,胡焕庸线东西两侧人口比重的差距比仅考虑SSPs情景时要有所缩小。前者的原因是胡线东侧地区城市规模和等级远高于胡线西侧地区,在中国人口城市化大背景下,胡线东侧人口占比相对提升。而后者原因是受气候变化影响,胡焕庸线西侧地区的水热条件变化较之东侧有利,从而更进一步提高了人口的环境承载力。② 中国的社会经济发展对胡焕庸线两侧人口比重的影响要远大于气候变化的影响。③ 从胡焕庸的北、中、南三段区域来探讨胡焕庸线突破的可能性,胡线中段区域由于黄河等河流流经区域有较好的水资源条件,有利于推进该区域的城镇化建设,成为人口向胡焕庸线以西迁移的突破口。

Hu Huanyong Line based on geographical synthesis:Simulation and prediction under SSPs-RCPs scenario matrix

In this paper, a population potential model under the influence of environmental factors is constructed, and four sets of the crop model and water model driven by climate system models are combined to simulate the spatiotemporal evolution trend of China's population in the near (2030) and medium (2050) periods under SSPs-RCPs scenario matrix. It is found that under the SSPs scenario, the gap between population proportions on the east and west sides of Hu Huanyong Line (also known as Hu Line) in China will be further enlarged in the future, while under the scenario of SSP-RCPS, the population proportion gap on both sides of the Hu Line will be somewhat narrowed compared with the SSP scenario alone. The reason for the former is that the urbanization development on the east side of the Hu Line is much higher than that on the west side. Under the background of population urbanization in China, the population on the east side of the Hu Line increases. The latter is due to the favorable change of hydrothermal conditions on the west side of the Hu Line under the influence of climate change, which further improves the environmental carrying capacity of the population. The impact of social and economic development on change of population proportion on both sides of the Hu Line is far greater than the impact of climate change. This paper aims to explore the possibility of the breakthrough of the Hu Line from north, middle and south sections. We believe that the middle section will act as the breakthrough point because the region where Yellow River and other rivers flow through have rich water resources, which is favorable to the development of urbanization.