共享社会经济路径下中国各省城市化水平预测

城市化水平预测与减缓及适应气候变化研究息息相关。基于国家统计局2005—2015年全国各省区城镇和乡村人口,以各省区2015年人均地区生产总值为指标进行分组,结合IPCC 5种共享社会经济路径（SSPs）的发展特征设置模型参数,运用Logistic模型预测了我国各省区2016—2050年城市化水平。结果表明,到2050年,各省区（除天津、北京、上海、西藏外）在5种典型SSPs下城市化水平收敛于75%左右。其中,SSP1、SSP3、SSP4、SSP5路径下,各省城市化水平比较趋同。而在SSP2路径下,全国总体上从东部到西部城市化程度逐渐降低,空间分布具有明显梯次递减性。5种SSPs路径下城市化速度方面,基本上呈现出中西部快而东部慢、西南快而东北慢的空间分布格局。同时,高收入省份不同路径下的城市化水平差别小,而中低收入省份的差别较大。

Provincial urbanization projected to 2050 under the shared socioeconomic pathways in China

Urbanization is a key aspect of development that is relevant to studies of mitigation, adaptation to climate change, and its impacts. Based on the data of urban and rural population in 31 provinces of China published by the National Bureau of Statistics from 2005 to 2015 and the data of GDP per capita in each province in 2015, combined with the shared socioeconomic pathways (SSPs) proposed by the IPCC and Logistic model, the levels of urbanization in 31 provinces (autonomous regions and municipalities) in China were projected from 2016 to 2050. This paper will be beneficial to the research of numerous uncertainties in the process of urbanization under different economic development pathways and be helpful for the decision making in different provinces. The results show that by 2050, the urbanization levels of all provinces (excluding Tianjin, Beijing, Shanghai and Tibet) under the five typical SSPs will converge to about 75%. Among them, under SSP1, SSP3, SSP4, and SSP5, the urbanization levels of all provinces will converge. Under SSP2, the overall urbanization level of the country from the east to the west will gradually decrease, and the spatial distribution of urbanization will have obvious step-down. In addition, under the SSPs, it basically shows that the urbanization of the west and the middle will be fast while the eastern slow and the spatial distribution pattern of the southwest is fast but the northeast is slow under SSPs. Differences across SSPs by 2050 may be small in the high-income region where the urbanization level is already high and the uncertainty in future urbanization trend is rather small. In contrast, many middle-income and low-income provinces are in the midst of the urbanization transition, with a big difference across the 5 pathways.