Projection of Population in Rural Revitalization Areas of China under Climate Change Scenario and Its Application in Drought Disaster Impact Assessment

In this study, 14 rural revitalization areas of China were selected as the study areas. The localized population parameters for the population development environment (PDE) model under different shared socio-economic paths (SSPs) were set by considering China’s population characteristics. Then, the population change characteristics of the 14 rural revitalization areas from 2020 to 2040 were estimated based on the PDE model. Combined with the multimodel drought assessment results under shared socioeconomic pathway–representative concentration pathway (SSP–RCP) scenarios, the change characteristics of drought exposed population in the future were compared with a baseline period (1995–2014). The results show that: (1) The population of China’s rural revitalization areas under SSP1, SSP4, and SSP5 scenarios show a downward trend; the population under the SSP2 remains stable and that under the SSP3 continues to grow; the population under each SSP scenario is projected to be 230–266 million in 2040, accounting for 16.7%–18.1% of China’s population. (2) In terms of the age structure, the proportion of the elderly population in 2040 under SSP1, SSP4, and SSP5 scenarios are relatively higher, and the number of freshmen is very small, which may result in an aging problem; the age structure is relatively balanced under the SSP2 scenario, the newborn population is high, and the working population is relatively large under the SSP3. (3) The annual average drought frequency and exposed population from 2020 to 2040 under all the SSP–RCP scenarios except for SSP3–7.0 are projected to increase compared with the baseline period; the spatial pattern of the change of population exposed to drought is relatively consistent under different SSP–RCP scenarios; more than 60% of the regions are projected to increase compared with the reference period, among which the increased range is the highest in the southwest and central regions. In contrast, the exposed population in Dabie Mountain Area is projected to decrease slightly. (4) Different age groups are affected by drought to varying degrees; children are more exposed to drought under the SSP3–7.0 scenario, while the elderly are more affected under the SSP5–8.5 scenario.